docs: Add more documentation for the CC3200 in the pyb module.
This commit is contained in:
Daniel Campora
parent
cdfa11f550
commit
ea2cc2b907
@ -315,8 +315,9 @@ STATIC void pyb_timer_print(const mp_print_t *print, mp_obj_t self_in, mp_print_
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/// Initialise the timer. Initialisation must give the desired mode
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/// and an optional timer width
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///
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/// tim.init(mode=Timer.ONE_SHOT, width=32) # one shot mode
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/// tim.init(mode=Timer.PERIODIC) # configure in free running periodic mode
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/// tim.init(mode=Timer.ONE_SHOT, width=16) # one shot mode splitted into two 16-bit independent timers
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/// split into two 16-bit independent timers
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///
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/// Keyword arguments:
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///
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@ -326,7 +327,7 @@ STATIC void pyb_timer_print(const mp_print_t *print, mp_obj_t self_in, mp_print_
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STATIC mp_obj_t pyb_timer_init_helper(pyb_timer_obj_t *tim, mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
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static const mp_arg_t allowed_args[] = {
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{ MP_QSTR_mode, MP_ARG_REQUIRED | MP_ARG_INT, },
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{ MP_QSTR_width, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 32} },
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{ MP_QSTR_width, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 16} },
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};
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// parse args
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@ -405,7 +406,7 @@ STATIC mp_obj_t pyb_timer_deinit(mp_obj_t self_in) {
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}
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STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_timer_deinit_obj, pyb_timer_deinit);
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/// \method channel(channel, *, freq, polarity, duty_cycle)
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/// \method channel(channel, *, freq, period, polarity, duty_cycle)
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/// Initialise the timer channel. Initialization requires at least a frequency param. With no
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/// extra params given besides the channel id, the channel is returned with the previous configuration
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/// os 'None', if it hasn't been initialized before.
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@ -735,7 +736,7 @@ STATIC mp_obj_t pyb_timer_channel_duty_cycle(mp_uint_t n_args, const mp_obj_t *a
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}
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STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_timer_channel_duty_cycle_obj, 1, 3, pyb_timer_channel_duty_cycle);
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/// \method callback(handler, value, priority)
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/// \method callback(handler, priority, value)
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/// create a callback object associated with the timer channel
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STATIC mp_obj_t pyb_timer_channel_callback (mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
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mp_arg_val_t args[mpcallback_INIT_NUM_ARGS];
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@ -753,10 +754,21 @@ STATIC mp_obj_t pyb_timer_channel_callback (mp_uint_t n_args, const mp_obj_t *po
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goto invalid_args;
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}
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uint32_t _config = (ch->channel == TIMER_B) ? ((ch->timer->config & TIMER_B) >> 8) : (ch->timer->config & TIMER_A);
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// validate and set the value if we are in edge count mode
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if (_config == TIMER_CFG_A_CAP_COUNT) {
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uint32_t c_value = args[3].u_int;
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if (!c_value || c_value > 0xFFFF) {
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// zero or exceeds the maximum value of a 16-bit timer
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goto invalid_args;
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}
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MAP_TimerMatchSet(ch->timer->timer, ch->channel, c_value);
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}
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// disable the callback first
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pyb_timer_channel_callback_disable(ch);
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uint32_t _config = (ch->channel == TIMER_B) ? ((ch->timer->config & TIMER_B) >> 8) : (ch->timer->config & TIMER_A);
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uint8_t shift = (ch->channel == TIMER_B) ? 8 : 0;
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switch (_config) {
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case TIMER_CFG_A_ONE_SHOT:
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@ -778,13 +790,9 @@ STATIC mp_obj_t pyb_timer_channel_callback (mp_uint_t n_args, const mp_obj_t *po
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default:
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break;
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}
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// special case for a 32-bit timer
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if (ch->channel == (TIMER_A | TIMER_B)) {
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// again a special case for the pwm match interrupt
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if (_config == TIMER_CFG_A_PWM) {
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ch->timer->intflags |= TIMER_TIMB_MATCH;
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} else {
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ch->timer->intflags |= (ch->timer->intflags << 8);
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}
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ch->timer->intflags |= (ch->timer->intflags << 8);
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}
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void (*pfnHandler)(void);
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@ -835,6 +843,12 @@ STATIC mp_obj_t pyb_timer_channel_callback (mp_uint_t n_args, const mp_obj_t *po
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// create the callback
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_callback = mpcallback_new (ch, args[1].u_obj, &pyb_timer_channel_cb_methods);
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// reload the timer
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uint32_t period_c;
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uint32_t match;
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compute_prescaler_period_and_match_value(ch, &period_c, &match);
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MAP_TimerLoadSet(ch->timer->timer, ch->channel, period_c);
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// enable the callback before returning
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pyb_timer_channel_callback_enable(ch);
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}
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@ -262,9 +262,9 @@ Methods
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Return a 5-tuple with the configuration of the pin:
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``(name, alternate-function, mode, type, strength)``
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.. method:: pin.callback(mode, priority=1, handler=None, wakes=pyb.Sleep.ACTIVE)
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.. method:: pin.callback(\*, mode, priority=1, handler=None, wakes=pyb.Sleep.ACTIVE)
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Create a callback to be triggered when data is received on the UART.
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Create a callback to be triggered when the input level at the pin changes.
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- ``mode`` configures the pin level which can generate an interrupt. Possible values are:
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@ -286,8 +286,8 @@ Methods
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of this pins can be enabled as a wake source at the same time, so, only
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the last enabled pin as a ``pyb.Sleep.SUSPENDED`` wake source will have effect.
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- If ``wakes=pyb.Sleep.SUSPENDED`` pins ``GPIO2``, ``GPIO4``, ``GPIO10``,
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``GPIO11``, GPIO17`` and ``GPIO24`` can wake the board. In this case all this 6
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pins can be enabled as a ``pyb.Sleep.HIBERNATE`` wake source at the same time.
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``GPIO11``, ``GPIO17`` and ``GPIO24`` can wake the board. In this case all of the
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6 pins can be enabled as a ``pyb.Sleep.HIBERNATE`` wake source at the same time.
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- Values can be ORed to make a pin generate interrupts in more than one power
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mode.
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@ -32,13 +32,23 @@ Methods
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date and time. With 1 argument (being an 8-tuple) it sets the date
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and time.
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The 8-tuple has the following format:
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.. only:: port_pyboard
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(year, month, day, weekday, hours, minutes, seconds, subseconds)
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The 8-tuple has the following format:
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(year, month, day, weekday, hours, minutes, seconds, subseconds)
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``weekday`` is 1-7 for Monday through Sunday.
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``subseconds`` counts down from 255 to 0
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.. only:: port_wipy
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``weekday`` is 1-7 for Monday through Sunday.
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``subseconds`` counts down from 255 to 0
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The 8-tuple has the following format:
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``(year, month, day, weekday, hours, minutes, seconds, milliseconds)``
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``weekday`` is 0-6 for Monday through Sunday.
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.. only:: port_pyboard
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@ -15,7 +15,7 @@ Example usage::
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# data, clk and cmd pins must be passed along with
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# their respective alternate functions
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sd = pyb.SD('GPIO15', 8, 'GPIO16', 8, 'GPIO17', 8)
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sd = pyb.SD('GPIO15', 8, 'GPIO10', 6, 'GPIO11', 6)
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sd.enable() # enable and mount the SD card
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sd.disable() # disable and unmount it
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@ -3,214 +3,339 @@
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class Timer -- control internal timers
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======================================
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Timers can be used for a great variety of tasks. At the moment, only
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the simplest case is implemented: that of calling a function periodically.
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.. only:: port_pyboard
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Each timer consists of a counter that counts up at a certain rate. The rate
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at which it counts is the peripheral clock frequency (in Hz) divided by the
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timer prescaler. When the counter reaches the timer period it triggers an
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event, and the counter resets back to zero. By using the callback method,
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the timer event can call a Python function.
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Timers can be used for a great variety of tasks. At the moment, only
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the simplest case is implemented: that of calling a function periodically.
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Each timer consists of a counter that counts up at a certain rate. The rate
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at which it counts is the peripheral clock frequency (in Hz) divided by the
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timer prescaler. When the counter reaches the timer period it triggers an
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event, and the counter resets back to zero. By using the callback method,
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the timer event can call a Python function.
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Example usage to toggle an LED at a fixed frequency::
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tim = pyb.Timer(4) # create a timer object using timer 4
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tim.init(freq=2) # trigger at 2Hz
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tim.callback(lambda t:pyb.LED(1).toggle())
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Example using named function for the callback::
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def tick(timer): # we will receive the timer object when being called
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print(timer.counter()) # show current timer's counter value
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tim = pyb.Timer(4, freq=1) # create a timer object using timer 4 - trigger at 1Hz
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tim.callback(tick) # set the callback to our tick function
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Further examples::
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tim = pyb.Timer(4, freq=100) # freq in Hz
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tim = pyb.Timer(4, prescaler=0, period=99)
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tim.counter() # get counter (can also set)
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tim.prescaler(2) # set prescaler (can also get)
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tim.period(199) # set period (can also get)
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tim.callback(lambda t: ...) # set callback for update interrupt (t=tim instance)
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tim.callback(None) # clear callback
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*Note:* Timer 3 is reserved for internal use. Timer 5 controls
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the servo driver, and Timer 6 is used for timed ADC/DAC reading/writing.
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It is recommended to use the other timers in your programs.
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Example usage to toggle an LED at a fixed frequency::
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.. only:: port_wipy
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tim = pyb.Timer(4) # create a timer object using timer 4
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tim.init(freq=2) # trigger at 2Hz
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tim.callback(lambda t:pyb.LED(1).toggle())
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Timers can be used for a great variety of tasks, calling a function periodically,
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counting events, and generating a PWM signal are among the most common use cases.
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Each timer consists of 2 16-bit channels and this channels can be tied together to
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form 1 32-bit timer. The operating mode needs to be configured per timer, but then
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the period (or the frequency) can be independently configured on each channel.
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By using the callback method, the timer event can call a Python function.
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Example using named function for the callback::
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Example usage to toggle an LED at a fixed frequency::
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def tick(timer): # we will receive the timer object when being called
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print(timer.counter()) # show current timer's counter value
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tim = pyb.Timer(4, freq=1) # create a timer object using timer 4 - trigger at 1Hz
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tim.callback(tick) # set the callback to our tick function
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tim = pyb.Timer(4) # create a timer object using timer 4
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tim.init(mode=Timer.PERIODIC) # initialize it in periodic mode
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tim_ch = tim.channel(Timer.A, freq=2) # configure channel A at a frequency of 2Hz
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tim_ch.callback(handler=lambda t:led.toggle()) # toggle a LED on every cycle of the timer
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Further examples::
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Example using named function for the callback::
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tim = pyb.Timer(4, freq=100) # freq in Hz
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tim = pyb.Timer(4, prescaler=0, period=99)
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tim.counter() # get counter (can also set)
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tim.prescaler(2) # set prescaler (can also get)
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tim.period(199) # set period (can also get)
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tim.callback(lambda t: ...) # set callback for update interrupt (t=tim instance)
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tim.callback(None) # clear callback
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tim = Timer(1, mode=Timer.PERIODIC)
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tim_a = tim.channel(Timer.A, freq=1000)
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led = Pin('GPIO2', af=0, mode=Pin.OUT)
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def tick(timer): # we will receive the timer object when being called
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print(timer.time()) # show current timer's time value (is microseconds)
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led.toggle() # toggle the LED
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tim_a.callback(handler=tick)
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Further examples::
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tim1 = pyb.Timer(2, mode=Timer.EVENT_COUNT) # initialize it capture mode
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tim2 = pyb.Timer(1, mode=Timer.PWM) # initialize it in PWM mode
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tim_ch = tim1.channel(Timer.A, freq=1, polarity=Timer.POSITIVE) # start the event counter with a frequency of 1Hz and triggered by positive edges
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tim_ch = tim2.channel(Timer.B, freq=10000, duty_cycle=50) # start the PWM on channel B with a 50% duty cycle
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tim_ch.time() # get the current time in usec (can also be set)
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tim_ch.freq(20) # set the frequency (can also get)
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tim_ch.duty_cycle(30) # set the duty cycle to 30% (can also get)
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tim_ch.duty_cycle(30, Timer.NEGATIVE) # set the duty cycle to 30% and change the polarity to negative
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tim_ch.event_count() # get the number of captured events
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tim_ch.event_time() # get the the time of the last captured event
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tim_ch.period(2000000) # change the period to 2 seconds
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*Note:* Timer 3 is reserved for internal use. Timer 5 controls
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the servo driver, and Timer 6 is used for timed ADC/DAC reading/writing.
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It is recommended to use the other timers in your programs.
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*Note:* Memory can't be allocated during a callback (an interrupt) and so
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exceptions raised within a callback don't give much information. See
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:func:`micropython.alloc_emergency_exception_buf` for how to get around this
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limitation.
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Constructors
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------------
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.. class:: pyb.Timer(id, ...)
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Construct a new timer object of the given id. If additional
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arguments are given, then the timer is initialised by ``init(...)``.
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``id`` can be 1 to 14, excluding 3.
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.. only:: port_pyboard
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Construct a new timer object of the given id. If additional
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arguments are given, then the timer is initialised by ``init(...)``.
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``id`` can be 1 to 14, excluding 3.
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.. only:: port_wipy
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Construct a new timer object of the given id. If additional
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arguments are given, then the timer is initialised by ``init(...)``.
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``id`` can be 1 to 4.
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Methods
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-------
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.. method:: timer.callback(fun)
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.. only:: port_pyboard
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Set the function to be called when the timer triggers.
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``fun`` is passed 1 argument, the timer object.
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If ``fun`` is ``None`` then the callback will be disabled.
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.. method:: timer.channel(channel, mode, ...)
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If only a channel number is passed, then a previously initialized channel
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object is returned (or ``None`` if there is no previous channel).
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Othwerwise, a TimerChannel object is initialized and returned.
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Each channel can be configured to perform pwm, output compare, or
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input capture. All channels share the same underlying timer, which means
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that they share the same timer clock.
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Keyword arguments:
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- ``mode`` can be one of:
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- ``Timer.PWM`` --- configure the timer in PWM mode (active high).
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- ``Timer.PWM_INVERTED`` --- configure the timer in PWM mode (active low).
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- ``Timer.OC_TIMING`` --- indicates that no pin is driven.
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- ``Timer.OC_ACTIVE`` --- the pin will be made active when a compare match occurs (active is determined by polarity)
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- ``Timer.OC_INACTIVE`` --- the pin will be made inactive when a compare match occurs.
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- ``Timer.OC_TOGGLE`` --- the pin will be toggled when an compare match occurs.
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- ``Timer.OC_FORCED_ACTIVE`` --- the pin is forced active (compare match is ignored).
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- ``Timer.OC_FORCED_INACTIVE`` --- the pin is forced inactive (compare match is ignored).
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- ``Timer.IC`` --- configure the timer in Input Capture mode.
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- ``Timer.ENC_A`` --- configure the timer in Encoder mode. The counter only changes when CH1 changes.
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- ``Timer.ENC_B`` --- configure the timer in Encoder mode. The counter only changes when CH2 changes.
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- ``Timer.ENC_AB`` --- configure the timer in Encoder mode. The counter changes when CH1 or CH2 changes.
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- ``callback`` - as per TimerChannel.callback()
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- ``pin`` None (the default) or a Pin object. If specified (and not None)
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this will cause the alternate function of the the indicated pin
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to be configured for this timer channel. An error will be raised if
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the pin doesn't support any alternate functions for this timer channel.
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Keyword arguments for Timer.PWM modes:
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- ``pulse_width`` - determines the initial pulse width value to use.
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- ``pulse_width_percent`` - determines the initial pulse width percentage to use.
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Keyword arguments for Timer.OC modes:
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- ``compare`` - determines the initial value of the compare register.
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- ``polarity`` can be one of:
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- ``Timer.HIGH`` - output is active high
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- ``Timer.LOW`` - output is acive low
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Optional keyword arguments for Timer.IC modes:
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- ``polarity`` can be one of:
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- ``Timer.RISING`` - captures on rising edge.
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- ``Timer.FALLING`` - captures on falling edge.
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- ``Timer.BOTH`` - captures on both edges.
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Note that capture only works on the primary channel, and not on the
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complimentary channels.
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Notes for Timer.ENC modes:
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- Requires 2 pins, so one or both pins will need to be configured to use
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the appropriate timer AF using the Pin API.
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- Read the encoder value using the timer.counter() method.
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- Only works on CH1 and CH2 (and not on CH1N or CH2N)
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- The channel number is ignored when setting the encoder mode.
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.. method:: timer.init(\*, freq, prescaler, period)
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Initialise the timer. Initialisation must be either by frequency (in Hz)
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or by prescaler and period::
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PWM Example::
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timer = pyb.Timer(2, freq=1000)
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ch2 = timer.channel(2, pyb.Timer.PWM, pin=pyb.Pin.board.X2, pulse_width=8000)
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ch3 = timer.channel(3, pyb.Timer.PWM, pin=pyb.Pin.board.X3, pulse_width=16000)
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tim.init(freq=100) # set the timer to trigger at 100Hz
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tim.init(prescaler=83, period=999) # set the prescaler and period directly
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Keyword arguments:
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- ``freq`` --- specifies the periodic frequency of the timer. You migh also
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view this as the frequency with which the timer goes through one complete cycle.
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- ``prescaler`` [0-0xffff] - specifies the value to be loaded into the
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timer's Prescaler Register (PSC). The timer clock source is divided by
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(``prescaler + 1``) to arrive at the timer clock. Timers 2-7 and 12-14
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have a clock source of 84 MHz (pyb.freq()[2] \* 2), and Timers 1, and 8-11
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have a clock source of 168 MHz (pyb.freq()[3] \* 2).
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- ``period`` [0-0xffff] for timers 1, 3, 4, and 6-15. [0-0x3fffffff] for timers 2 & 5.
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Specifies the value to be loaded into the timer's AutoReload
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Register (ARR). This determines the period of the timer (i.e. when the
|
||||
counter cycles). The timer counter will roll-over after ``period + 1``
|
||||
timer clock cycles.
|
||||
|
||||
- ``mode`` can be one of:
|
||||
|
||||
- ``Timer.UP`` - configures the timer to count from 0 to ARR (default)
|
||||
- ``Timer.DOWN`` - configures the timer to count from ARR down to 0.
|
||||
- ``Timer.CENTER`` - confgures the timer to count from 0 to ARR and
|
||||
then back down to 0.
|
||||
|
||||
- ``div`` can be one of 1, 2, or 4. Divides the timer clock to determine
|
||||
the sampling clock used by the digital filters.
|
||||
|
||||
- ``callback`` - as per Timer.callback()
|
||||
|
||||
- ``deadtime`` - specifies the amount of "dead" or inactive time between
|
||||
transitions on complimentary channels (both channels will be inactive)
|
||||
for this time). ``deadtime`` may be an integer between 0 and 1008, with
|
||||
the following restrictions: 0-128 in steps of 1. 128-256 in steps of
|
||||
2, 256-512 in steps of 8, and 512-1008 in steps of 16. ``deadime``
|
||||
measures ticks of ``source_freq`` divided by ``div`` clock ticks.
|
||||
``deadtime`` is only available on timers 1 and 8.
|
||||
|
||||
You must either specify freq or both of period and prescaler.
|
||||
|
||||
.. method:: timer.counter([value])
|
||||
.. only:: port_wipy
|
||||
|
||||
Get or set the timer counter.
|
||||
.. method:: timer.init(mode, \*, width=16)
|
||||
|
||||
Initialise the timer. Example::
|
||||
|
||||
tim.init(Timer.PERIODIC) # periodic 16-bit timer
|
||||
tim.init(Timer.ONE_SHOT, width=32) # one shot 32-bit timer
|
||||
|
||||
Keyword arguments:
|
||||
|
||||
- ``mode`` can be one of:
|
||||
|
||||
- ``Timer.ONE_SHOT`` - The timer runs once until the configured
|
||||
period of the channel expires.
|
||||
- ``Timer.PERIODIC`` - The timer runs periodically at the configured
|
||||
frequency of the channel.
|
||||
- ``Timer.EDGE_TIME`` - Meaure the time pin level changes.
|
||||
- ``Timer.EDGE_COUNT`` - Count the number of pin level changes.
|
||||
|
||||
- ``width`` must be either 16 or 32 (bits). For really low frequencies <= ~1Hz
|
||||
(or large periods), 32-bit timers should be used. 32-bit mode is only available
|
||||
for ``ONE_SHOT`` AND ``PERIODIC`` modes.
|
||||
|
||||
.. method:: timer.deinit()
|
||||
|
||||
Deinitialises the timer.
|
||||
|
||||
Disables the callback (and the associated irq).
|
||||
.. only:: port_pyboard
|
||||
|
||||
Disables the callback (and the associated irq).
|
||||
|
||||
Disables any channel callbacks (and the associated irq).
|
||||
Stops the timer, and disables the timer peripheral.
|
||||
|
||||
.. method:: timer.freq([value])
|
||||
.. only:: port_pyboard
|
||||
|
||||
Get or set the frequency for the timer (changes prescaler and period if set).
|
||||
.. method:: timer.callback(fun)
|
||||
|
||||
Set the function to be called when the timer triggers.
|
||||
``fun`` is passed 1 argument, the timer object.
|
||||
If ``fun`` is ``None`` then the callback will be disabled.
|
||||
|
||||
.. method:: timer.init(\*, freq, prescaler, period)
|
||||
.. only:: port_pyboard
|
||||
|
||||
Initialise the timer. Initialisation must be either by frequency (in Hz)
|
||||
or by prescaler and period::
|
||||
|
||||
tim.init(freq=100) # set the timer to trigger at 100Hz
|
||||
tim.init(prescaler=83, period=999) # set the prescaler and period directly
|
||||
|
||||
Keyword arguments:
|
||||
|
||||
- ``freq`` --- specifies the periodic frequency of the timer. You migh also
|
||||
view this as the frequency with which the timer goes through one complete cycle.
|
||||
|
||||
- ``prescaler`` [0-0xffff] - specifies the value to be loaded into the
|
||||
timer's Prescaler Register (PSC). The timer clock source is divided by
|
||||
(``prescaler + 1``) to arrive at the timer clock. Timers 2-7 and 12-14
|
||||
have a clock source of 84 MHz (pyb.freq()[2] \* 2), and Timers 1, and 8-11
|
||||
have a clock source of 168 MHz (pyb.freq()[3] \* 2).
|
||||
|
||||
- ``period`` [0-0xffff] for timers 1, 3, 4, and 6-15. [0-0x3fffffff] for timers 2 & 5.
|
||||
Specifies the value to be loaded into the timer's AutoReload
|
||||
Register (ARR). This determines the period of the timer (i.e. when the
|
||||
counter cycles). The timer counter will roll-over after ``period + 1``
|
||||
timer clock cycles.
|
||||
|
||||
- ``mode`` can be one of:
|
||||
.. method:: timer.channel(channel, mode, ...)
|
||||
|
||||
If only a channel number is passed, then a previously initialized channel
|
||||
object is returned (or ``None`` if there is no previous channel).
|
||||
|
||||
Othwerwise, a TimerChannel object is initialized and returned.
|
||||
|
||||
Each channel can be configured to perform pwm, output compare, or
|
||||
input capture. All channels share the same underlying timer, which means
|
||||
that they share the same timer clock.
|
||||
|
||||
Keyword arguments:
|
||||
|
||||
- ``mode`` can be one of:
|
||||
|
||||
- ``Timer.PWM`` --- configure the timer in PWM mode (active high).
|
||||
- ``Timer.PWM_INVERTED`` --- configure the timer in PWM mode (active low).
|
||||
- ``Timer.OC_TIMING`` --- indicates that no pin is driven.
|
||||
- ``Timer.OC_ACTIVE`` --- the pin will be made active when a compare match occurs (active is determined by polarity)
|
||||
- ``Timer.OC_INACTIVE`` --- the pin will be made inactive when a compare match occurs.
|
||||
- ``Timer.OC_TOGGLE`` --- the pin will be toggled when an compare match occurs.
|
||||
- ``Timer.OC_FORCED_ACTIVE`` --- the pin is forced active (compare match is ignored).
|
||||
- ``Timer.OC_FORCED_INACTIVE`` --- the pin is forced inactive (compare match is ignored).
|
||||
- ``Timer.IC`` --- configure the timer in Input Capture mode.
|
||||
- ``Timer.ENC_A`` --- configure the timer in Encoder mode. The counter only changes when CH1 changes.
|
||||
- ``Timer.ENC_B`` --- configure the timer in Encoder mode. The counter only changes when CH2 changes.
|
||||
- ``Timer.ENC_AB`` --- configure the timer in Encoder mode. The counter changes when CH1 or CH2 changes.
|
||||
|
||||
- ``callback`` - as per TimerChannel.callback()
|
||||
|
||||
- ``pin`` None (the default) or a Pin object. If specified (and not None)
|
||||
this will cause the alternate function of the the indicated pin
|
||||
to be configured for this timer channel. An error will be raised if
|
||||
the pin doesn't support any alternate functions for this timer channel.
|
||||
|
||||
Keyword arguments for Timer.PWM modes:
|
||||
|
||||
- ``pulse_width`` - determines the initial pulse width value to use.
|
||||
- ``pulse_width_percent`` - determines the initial pulse width percentage to use.
|
||||
|
||||
Keyword arguments for Timer.OC modes:
|
||||
|
||||
- ``compare`` - determines the initial value of the compare register.
|
||||
|
||||
- ``polarity`` can be one of:
|
||||
|
||||
- ``Timer.HIGH`` - output is active high
|
||||
- ``Timer.LOW`` - output is acive low
|
||||
|
||||
Optional keyword arguments for Timer.IC modes:
|
||||
|
||||
- ``polarity`` can be one of:
|
||||
|
||||
- ``Timer.RISING`` - captures on rising edge.
|
||||
- ``Timer.FALLING`` - captures on falling edge.
|
||||
- ``Timer.BOTH`` - captures on both edges.
|
||||
|
||||
Note that capture only works on the primary channel, and not on the
|
||||
complimentary channels.
|
||||
|
||||
Notes for Timer.ENC modes:
|
||||
|
||||
- Requires 2 pins, so one or both pins will need to be configured to use
|
||||
the appropriate timer AF using the Pin API.
|
||||
- Read the encoder value using the timer.counter() method.
|
||||
- Only works on CH1 and CH2 (and not on CH1N or CH2N)
|
||||
- The channel number is ignored when setting the encoder mode.
|
||||
|
||||
PWM Example::
|
||||
|
||||
timer = pyb.Timer(2, freq=1000)
|
||||
ch2 = timer.channel(2, pyb.Timer.PWM, pin=pyb.Pin.board.X2, pulse_width=8000)
|
||||
ch3 = timer.channel(3, pyb.Timer.PWM, pin=pyb.Pin.board.X3, pulse_width=16000)
|
||||
|
||||
- ``Timer.UP`` - configures the timer to count from 0 to ARR (default)
|
||||
- ``Timer.DOWN`` - configures the timer to count from ARR down to 0.
|
||||
- ``Timer.CENTER`` - confgures the timer to count from 0 to ARR and
|
||||
then back down to 0.
|
||||
|
||||
- ``div`` can be one of 1, 2, or 4. Divides the timer clock to determine
|
||||
the sampling clock used by the digital filters.
|
||||
|
||||
- ``callback`` - as per Timer.callback()
|
||||
|
||||
- ``deadtime`` - specifies the amount of "dead" or inactive time between
|
||||
transitions on complimentary channels (both channels will be inactive)
|
||||
for this time). ``deadtime`` may be an integer between 0 and 1008, with
|
||||
the following restrictions: 0-128 in steps of 1. 128-256 in steps of
|
||||
2, 256-512 in steps of 8, and 512-1008 in steps of 16. ``deadime``
|
||||
measures ticks of ``source_freq`` divided by ``div`` clock ticks.
|
||||
``deadtime`` is only available on timers 1 and 8.
|
||||
|
||||
You must either specify freq or both of period and prescaler.
|
||||
.. only:: port_wipy
|
||||
|
||||
.. method:: timer.period([value])
|
||||
.. method:: timer.channel(channel, \**, freq, period, polarity=Timer.POSITIVE, duty_cycle=0)
|
||||
|
||||
If only a channel identifier passed, then a previously initialized channel
|
||||
object is returned (or ``None`` if there is no previous channel).
|
||||
|
||||
Othwerwise, a TimerChannel object is initialized and returned.
|
||||
|
||||
The operating mode is is the one configured to the Timer object that was used to
|
||||
create the channel.
|
||||
|
||||
Get or set the period of the timer.
|
||||
- ``channel`` if the width of the timer is 16-bit, then must be either ``TIMER.A``, ``TIMER.B``.
|
||||
If the width is 32-bit then it **must be** ``TIMER.A | TIMER.B``.
|
||||
|
||||
.. method:: timer.prescaler([value])
|
||||
Keyword only arguments:
|
||||
|
||||
Get or set the prescaler for the timer.
|
||||
- ``freq`` sets the frequency in Hz.
|
||||
- ``period`` sets the period in microseconds.
|
||||
|
||||
.. method:: timer.source_freq()
|
||||
.. note::
|
||||
|
||||
Get the frequency of the source of the timer.
|
||||
Either ``freq`` or ``period`` must be given, never both.
|
||||
|
||||
- ``polarity`` this is applicable for:
|
||||
|
||||
- ``PWM``, defines the polarity of the duty cycle
|
||||
- ``EDGE_TIME`` and ``EDGE_COUNT``, defines the polarity of the pin level change to detect.
|
||||
To detect both rising and falling edges, make ``polarity=Timer.POSITIVE | Timer.NEGATIVE``.
|
||||
- ``duty_cycle`` only applicable to ``PWM``. It's a percentage (0-100)
|
||||
|
||||
.. only:: port_pyboard
|
||||
|
||||
.. method:: timer.counter([value])
|
||||
|
||||
Get or set the timer counter.
|
||||
|
||||
.. only:: port_pyboard
|
||||
|
||||
.. method:: timer.freq([value])
|
||||
|
||||
Get or set the frequency for the timer (changes prescaler and period if set).
|
||||
|
||||
.. only:: port_pyboard
|
||||
|
||||
.. method:: timer.period([value])
|
||||
|
||||
Get or set the period of the timer.
|
||||
|
||||
.. method:: timer.prescaler([value])
|
||||
|
||||
Get or set the prescaler for the timer.
|
||||
|
||||
.. method:: timer.source_freq()
|
||||
|
||||
Get the frequency of the source of the timer.
|
||||
|
||||
class TimerChannel --- setup a channel for a timer
|
||||
==================================================
|
||||
@ -222,37 +347,93 @@ TimerChannel objects are created using the Timer.channel() method.
|
||||
Methods
|
||||
-------
|
||||
|
||||
.. method:: timerchannel.callback(fun)
|
||||
.. only:: port_pyboard
|
||||
|
||||
Set the function to be called when the timer channel triggers.
|
||||
``fun`` is passed 1 argument, the timer object.
|
||||
If ``fun`` is ``None`` then the callback will be disabled.
|
||||
.. method:: timerchannel.callback(fun)
|
||||
|
||||
.. method:: timerchannel.capture([value])
|
||||
Set the function to be called when the timer channel triggers.
|
||||
``fun`` is passed 1 argument, the timer object.
|
||||
If ``fun`` is ``None`` then the callback will be disabled.
|
||||
|
||||
Get or set the capture value associated with a channel.
|
||||
capture, compare, and pulse_width are all aliases for the same function.
|
||||
capture is the logical name to use when the channel is in input capture mode.
|
||||
.. only:: port_wipy
|
||||
|
||||
.. method:: timerchannel.compare([value])
|
||||
.. method:: timerchannel.callback(\**, value, priority=1, handler=None)
|
||||
|
||||
Get or set the compare value associated with a channel.
|
||||
capture, compare, and pulse_width are all aliases for the same function.
|
||||
compare is the logical name to use when the channel is in output compare mode.
|
||||
The behavior of this callback is heaviliy dependent on the operating
|
||||
mode of the timer channel:
|
||||
|
||||
.. method:: timerchannel.pulse_width([value])
|
||||
- If mode is ``Timer.PERIODIC`` the callback is executed periodically
|
||||
with the configured frequency or period.
|
||||
- If mode is ``Timer.ONE_SHOT`` the callback is executed once when
|
||||
the configured timer expires.
|
||||
- If mode is ``Timer.EDGE_COUNT`` the callback is executed when reaching
|
||||
the configured number of events (see ``value`` param below).
|
||||
- If mode is ``Timer.PWM`` the callback is executed when reaching the duty
|
||||
cycle value.
|
||||
|
||||
Get or set the pulse width value associated with a channel.
|
||||
capture, compare, and pulse_width are all aliases for the same function.
|
||||
pulse_width is the logical name to use when the channel is in PWM mode.
|
||||
|
||||
In edge aligned mode, a pulse_width of ``period + 1`` corresponds to a duty cycle of 100%
|
||||
In center aligned mode, a pulse width of ``period`` corresponds to a duty cycle of 100%
|
||||
The accepted params are:
|
||||
|
||||
.. method:: timerchannel.pulse_width_percent([value])
|
||||
- ``priority`` level of the interrupt. Can take values in the range 1-7.
|
||||
Higher values represent higher priorities.
|
||||
- ``handler`` is an optional function to be called when the interrupt is triggered.
|
||||
- ``value`` is **only valid** when in ``Timer.EDGE_COUNT`` mode and is used to set
|
||||
the number of edge events that will trigger the interrupt.
|
||||
|
||||
Get or set the pulse width percentage associated with a channel. The value
|
||||
is a number between 0 and 100 and sets the percentage of the timer period
|
||||
for which the pulse is active. The value can be an integer or
|
||||
floating-point number for more accuracy. For example, a value of 25 gives
|
||||
a duty cycle of 25%.
|
||||
Returns a callback object.
|
||||
|
||||
.. only:: port_pyboard
|
||||
|
||||
.. method:: timerchannel.capture([value])
|
||||
|
||||
Get or set the capture value associated with a channel.
|
||||
capture, compare, and pulse_width are all aliases for the same function.
|
||||
capture is the logical name to use when the channel is in input capture mode.
|
||||
|
||||
.. method:: timerchannel.compare([value])
|
||||
|
||||
Get or set the compare value associated with a channel.
|
||||
capture, compare, and pulse_width are all aliases for the same function.
|
||||
compare is the logical name to use when the channel is in output compare mode.
|
||||
|
||||
.. method:: timerchannel.pulse_width([value])
|
||||
|
||||
Get or set the pulse width value associated with a channel.
|
||||
capture, compare, and pulse_width are all aliases for the same function.
|
||||
pulse_width is the logical name to use when the channel is in PWM mode.
|
||||
|
||||
In edge aligned mode, a pulse_width of ``period + 1`` corresponds to a duty cycle of 100%
|
||||
In center aligned mode, a pulse width of ``period`` corresponds to a duty cycle of 100%
|
||||
|
||||
.. method:: timerchannel.pulse_width_percent([value])
|
||||
|
||||
Get or set the pulse width percentage associated with a channel. The value
|
||||
is a number between 0 and 100 and sets the percentage of the timer period
|
||||
for which the pulse is active. The value can be an integer or
|
||||
floating-point number for more accuracy. For example, a value of 25 gives
|
||||
a duty cycle of 25%.
|
||||
|
||||
.. only:: port_wipy
|
||||
|
||||
.. method:: timerchannel.freq([value])
|
||||
|
||||
Get or set the timer channel frequency (in Hz).
|
||||
|
||||
.. method:: timerchannel.period([value])
|
||||
|
||||
Get or set the timer channel period (in microseconds).
|
||||
|
||||
.. method:: timerchannel.time([value])
|
||||
|
||||
Get or set the timer channel current **time** value (in microseconds).
|
||||
|
||||
.. method:: timerchannel.event_count()
|
||||
|
||||
Get the number of edge events counted.
|
||||
|
||||
.. method:: timerchannel.event_time()
|
||||
|
||||
Get the time of ocurrance of the last event.
|
||||
|
||||
.. method:: timerchannel.duty_cycle([value])
|
||||
|
||||
Get or set the duty cycle of the PWM signal (in the range of 0-100).
|
||||
|
||||
@ -247,7 +247,7 @@ Miscellaneous functions
|
||||
|
||||
.. function:: repl_uart(uart)
|
||||
|
||||
Get or set the UART object that the REPL is repeated on.
|
||||
Get or set the UART object where the REPL is repeated on.
|
||||
|
||||
.. only:: port_pyboard
|
||||
|
||||
@ -269,13 +269,13 @@ Miscellaneous functions
|
||||
|
||||
.. function:: unique_id()
|
||||
|
||||
Returns a string of 12 bytes (96 bits), which is the unique ID for the MCU.
|
||||
Returns a string of 12 bytes (96 bits), which is the unique ID of the MCU.
|
||||
|
||||
.. only:: port_wipy
|
||||
|
||||
.. function:: unique_id()
|
||||
|
||||
Returns a string of 6 bytes (48 bits), which is the unique ID for the MCU.
|
||||
Returns a string of 6 bytes (48 bits), which is the unique ID of the MCU.
|
||||
This also corresponds to the ``MAC address`` of the WiPy.
|
||||
|
||||
Classes
|
||||
|
||||
@ -43,7 +43,7 @@ Constructors
|
||||
:class: attention
|
||||
|
||||
Due to hardware implementation details of the WiPy, data must be buffered before being
|
||||
digested, which would make impossible to calculate the hash of big blocks of data that
|
||||
digested, which would make it impossible to calculate the hash of big blocks of data that
|
||||
do not fit in RAM. In this case, since most likely the total size of the data is known
|
||||
in advance, the size can be passed to the constructor and hence the HASH hardware engine
|
||||
of the WiPy can be properly initialized without needing buffering. If ``block_size`` is
|
||||
|
||||
@ -1,6 +1,4 @@
|
||||
.. only:: port_pyboard
|
||||
|
||||
.. _quickref:
|
||||
.. _quickref:
|
||||
|
||||
Quick reference for the pyboard
|
||||
===============================
|
||||
|
||||
@ -35,12 +35,12 @@ If you power up normally, or press the reset button, the WiPy will boot
|
||||
into standard mode: the ``boot.py`` file will be executed first, then
|
||||
``main.py`` will run.
|
||||
|
||||
You can override this boot sequence by pulling ``GPIO28`` **up** during reset.
|
||||
The heart beat LED will flash slowly 3 times to signal that safe boot is being
|
||||
requested, and then 3 more times quickly to let you know that safe boot is
|
||||
going to be performed. While safe booting, the WiPy runs the factory firmware
|
||||
and skips the execution of ``boot.py`` and ``main.py``. This is useful to
|
||||
recover from any crash situation.
|
||||
You can override this boot sequence by pulling ``GPIO28`` **up** (connect
|
||||
it to the 3v3 output pin) during reset. The heart beat LED will flash slowly
|
||||
3 times to signal that safe boot is being requested, and then 3 more times
|
||||
quickly to let you know that safe boot is going to be performed. While safe
|
||||
booting, the WiPy runs the factory firmware and skips the execution of
|
||||
``boot.py`` and ``main.py``. This is useful to recover from any crash situation.
|
||||
|
||||
The heart beat LED
|
||||
------------------
|
||||
|
||||
@ -1,6 +1,4 @@
|
||||
.. only:: port_wipy
|
||||
|
||||
.. _quickref_:
|
||||
.. _quickref_:
|
||||
|
||||
Quick reference for the WiPy
|
||||
============================
|
||||
@ -20,7 +18,7 @@ See :mod:`pyb`. ::
|
||||
pyb.delay(50) # wait 50 milliseconds
|
||||
pyb.millis() # number of milliseconds since boot-up
|
||||
pyb.freq() # get the CPU frequency
|
||||
pyb.unique_id() # return the 6-byte unique id of the board (it's MAC address)
|
||||
pyb.unique_id() # return the 6-byte unique id of the board (the WiPy's MAC address)
|
||||
|
||||
Pins and GPIO
|
||||
-------------
|
||||
@ -176,7 +174,7 @@ See :ref:`pyb.SD <pyb.SD>`. ::
|
||||
|
||||
# SD card pins need special configuration so we pass 'em to the constructor
|
||||
# data pin, data af, clock pin, clock af, cmd pin, cmd af
|
||||
sd = SD('GPIO15', 8, 'GPIO16', 8, 'GPIO17', 8)
|
||||
sd = pyb.SD('GPIO15', 8, 'GPIO10', 6, 'GPIO11', 6)
|
||||
sd.enable()
|
||||
|
||||
WLAN (WiFi)
|
||||
@ -213,16 +211,16 @@ See ``pyb.Sleep``. ::
|
||||
Sleep.suspend() # everything except for WLAN is powered down (~950uA)
|
||||
# wakes from Pin, RTC or WLAN
|
||||
|
||||
Sleep.hibernate() # deepest sleep mode, mcu starts from reset. Wakes from Pin and RTC.
|
||||
Sleep.hibernate() # deepest sleep mode, MCU starts from reset. Wakes from Pin and RTC.
|
||||
|
||||
Heart beat LED
|
||||
-----------------------------
|
||||
--------------
|
||||
|
||||
See :ref:`pyb.HeartBeat <pyb.HeartBeat>`. ::
|
||||
|
||||
from pyb import HeartBeat
|
||||
|
||||
# disable the heart beat indication (you are free to use this led connected to GPIO25)
|
||||
HeartBeat.disable()
|
||||
# disable the heart beat indication (you are free to use this LED connected to GPIO25)
|
||||
HeartBeat().disable()
|
||||
# enable the heart beat again
|
||||
HeartBeat.enable()
|
||||
HeartBeat().enable()
|
||||
|
||||
Loading…
Reference in New Issue
Block a user