docs: Add more documentation for the CC3200 in the pyb module.

This commit is contained in:
Daniel Campora 2015-06-11 15:53:31 +02:00
parent cdfa11f550
commit ea2cc2b907
10 changed files with 432 additions and 231 deletions

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@ -315,8 +315,9 @@ STATIC void pyb_timer_print(const mp_print_t *print, mp_obj_t self_in, mp_print_
/// Initialise the timer. Initialisation must give the desired mode
/// and an optional timer width
///
/// tim.init(mode=Timer.ONE_SHOT, width=32) # one shot mode
/// tim.init(mode=Timer.PERIODIC) # configure in free running periodic mode
/// tim.init(mode=Timer.ONE_SHOT, width=16) # one shot mode splitted into two 16-bit independent timers
/// split into two 16-bit independent timers
///
/// Keyword arguments:
///
@ -326,7 +327,7 @@ STATIC void pyb_timer_print(const mp_print_t *print, mp_obj_t self_in, mp_print_
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) {
static const mp_arg_t allowed_args[] = {
{ MP_QSTR_mode, MP_ARG_REQUIRED | MP_ARG_INT, },
{ MP_QSTR_width, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 32} },
{ MP_QSTR_width, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 16} },
};
// parse args
@ -405,7 +406,7 @@ STATIC mp_obj_t pyb_timer_deinit(mp_obj_t self_in) {
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_timer_deinit_obj, pyb_timer_deinit);
/// \method channel(channel, *, freq, polarity, duty_cycle)
/// \method channel(channel, *, freq, period, polarity, duty_cycle)
/// Initialise the timer channel. Initialization requires at least a frequency param. With no
/// extra params given besides the channel id, the channel is returned with the previous configuration
/// os 'None', if it hasn't been initialized before.
@ -735,7 +736,7 @@ STATIC mp_obj_t pyb_timer_channel_duty_cycle(mp_uint_t n_args, const mp_obj_t *a
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_timer_channel_duty_cycle_obj, 1, 3, pyb_timer_channel_duty_cycle);
/// \method callback(handler, value, priority)
/// \method callback(handler, priority, value)
/// create a callback object associated with the timer channel
STATIC mp_obj_t pyb_timer_channel_callback (mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
mp_arg_val_t args[mpcallback_INIT_NUM_ARGS];
@ -753,10 +754,21 @@ STATIC mp_obj_t pyb_timer_channel_callback (mp_uint_t n_args, const mp_obj_t *po
goto invalid_args;
}
uint32_t _config = (ch->channel == TIMER_B) ? ((ch->timer->config & TIMER_B) >> 8) : (ch->timer->config & TIMER_A);
// validate and set the value if we are in edge count mode
if (_config == TIMER_CFG_A_CAP_COUNT) {
uint32_t c_value = args[3].u_int;
if (!c_value || c_value > 0xFFFF) {
// zero or exceeds the maximum value of a 16-bit timer
goto invalid_args;
}
MAP_TimerMatchSet(ch->timer->timer, ch->channel, c_value);
}
// disable the callback first
pyb_timer_channel_callback_disable(ch);
uint32_t _config = (ch->channel == TIMER_B) ? ((ch->timer->config & TIMER_B) >> 8) : (ch->timer->config & TIMER_A);
uint8_t shift = (ch->channel == TIMER_B) ? 8 : 0;
switch (_config) {
case TIMER_CFG_A_ONE_SHOT:
@ -778,13 +790,9 @@ STATIC mp_obj_t pyb_timer_channel_callback (mp_uint_t n_args, const mp_obj_t *po
default:
break;
}
// special case for a 32-bit timer
if (ch->channel == (TIMER_A | TIMER_B)) {
// again a special case for the pwm match interrupt
if (_config == TIMER_CFG_A_PWM) {
ch->timer->intflags |= TIMER_TIMB_MATCH;
} else {
ch->timer->intflags |= (ch->timer->intflags << 8);
}
ch->timer->intflags |= (ch->timer->intflags << 8);
}
void (*pfnHandler)(void);
@ -835,6 +843,12 @@ STATIC mp_obj_t pyb_timer_channel_callback (mp_uint_t n_args, const mp_obj_t *po
// create the callback
_callback = mpcallback_new (ch, args[1].u_obj, &pyb_timer_channel_cb_methods);
// reload the timer
uint32_t period_c;
uint32_t match;
compute_prescaler_period_and_match_value(ch, &period_c, &match);
MAP_TimerLoadSet(ch->timer->timer, ch->channel, period_c);
// enable the callback before returning
pyb_timer_channel_callback_enable(ch);
}

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@ -262,9 +262,9 @@ Methods
Return a 5-tuple with the configuration of the pin:
``(name, alternate-function, mode, type, strength)``
.. method:: pin.callback(mode, priority=1, handler=None, wakes=pyb.Sleep.ACTIVE)
.. method:: pin.callback(\*, mode, priority=1, handler=None, wakes=pyb.Sleep.ACTIVE)
Create a callback to be triggered when data is received on the UART.
Create a callback to be triggered when the input level at the pin changes.
- ``mode`` configures the pin level which can generate an interrupt. Possible values are:
@ -286,8 +286,8 @@ Methods
of this pins can be enabled as a wake source at the same time, so, only
the last enabled pin as a ``pyb.Sleep.SUSPENDED`` wake source will have effect.
- If ``wakes=pyb.Sleep.SUSPENDED`` pins ``GPIO2``, ``GPIO4``, ``GPIO10``,
``GPIO11``, GPIO17`` and ``GPIO24`` can wake the board. In this case all this 6
pins can be enabled as a ``pyb.Sleep.HIBERNATE`` wake source at the same time.
``GPIO11``, ``GPIO17`` and ``GPIO24`` can wake the board. In this case all of the
6 pins can be enabled as a ``pyb.Sleep.HIBERNATE`` wake source at the same time.
- Values can be ORed to make a pin generate interrupts in more than one power
mode.

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@ -32,13 +32,23 @@ Methods
date and time. With 1 argument (being an 8-tuple) it sets the date
and time.
The 8-tuple has the following format:
.. only:: port_pyboard
(year, month, day, weekday, hours, minutes, seconds, subseconds)
The 8-tuple has the following format:
(year, month, day, weekday, hours, minutes, seconds, subseconds)
``weekday`` is 1-7 for Monday through Sunday.
``subseconds`` counts down from 255 to 0
.. only:: port_wipy
``weekday`` is 1-7 for Monday through Sunday.
``subseconds`` counts down from 255 to 0
The 8-tuple has the following format:
``(year, month, day, weekday, hours, minutes, seconds, milliseconds)``
``weekday`` is 0-6 for Monday through Sunday.
.. only:: port_pyboard

View File

@ -15,7 +15,7 @@ Example usage::
# data, clk and cmd pins must be passed along with
# their respective alternate functions
sd = pyb.SD('GPIO15', 8, 'GPIO16', 8, 'GPIO17', 8)
sd = pyb.SD('GPIO15', 8, 'GPIO10', 6, 'GPIO11', 6)
sd.enable() # enable and mount the SD card
sd.disable() # disable and unmount it

View File

@ -3,214 +3,339 @@
class Timer -- control internal timers
======================================
Timers can be used for a great variety of tasks. At the moment, only
the simplest case is implemented: that of calling a function periodically.
.. only:: port_pyboard
Each timer consists of a counter that counts up at a certain rate. The rate
at which it counts is the peripheral clock frequency (in Hz) divided by the
timer prescaler. When the counter reaches the timer period it triggers an
event, and the counter resets back to zero. By using the callback method,
the timer event can call a Python function.
Timers can be used for a great variety of tasks. At the moment, only
the simplest case is implemented: that of calling a function periodically.
Each timer consists of a counter that counts up at a certain rate. The rate
at which it counts is the peripheral clock frequency (in Hz) divided by the
timer prescaler. When the counter reaches the timer period it triggers an
event, and the counter resets back to zero. By using the callback method,
the timer event can call a Python function.
Example usage to toggle an LED at a fixed frequency::
tim = pyb.Timer(4) # create a timer object using timer 4
tim.init(freq=2) # trigger at 2Hz
tim.callback(lambda t:pyb.LED(1).toggle())
Example using named function for the callback::
def tick(timer): # we will receive the timer object when being called
print(timer.counter()) # show current timer's counter value
tim = pyb.Timer(4, freq=1) # create a timer object using timer 4 - trigger at 1Hz
tim.callback(tick) # set the callback to our tick function
Further examples::
tim = pyb.Timer(4, freq=100) # freq in Hz
tim = pyb.Timer(4, prescaler=0, period=99)
tim.counter() # get counter (can also set)
tim.prescaler(2) # set prescaler (can also get)
tim.period(199) # set period (can also get)
tim.callback(lambda t: ...) # set callback for update interrupt (t=tim instance)
tim.callback(None) # clear callback
*Note:* Timer 3 is reserved for internal use. Timer 5 controls
the servo driver, and Timer 6 is used for timed ADC/DAC reading/writing.
It is recommended to use the other timers in your programs.
Example usage to toggle an LED at a fixed frequency::
.. only:: port_wipy
tim = pyb.Timer(4) # create a timer object using timer 4
tim.init(freq=2) # trigger at 2Hz
tim.callback(lambda t:pyb.LED(1).toggle())
Timers can be used for a great variety of tasks, calling a function periodically,
counting events, and generating a PWM signal are among the most common use cases.
Each timer consists of 2 16-bit channels and this channels can be tied together to
form 1 32-bit timer. The operating mode needs to be configured per timer, but then
the period (or the frequency) can be independently configured on each channel.
By using the callback method, the timer event can call a Python function.
Example using named function for the callback::
Example usage to toggle an LED at a fixed frequency::
def tick(timer): # we will receive the timer object when being called
print(timer.counter()) # show current timer's counter value
tim = pyb.Timer(4, freq=1) # create a timer object using timer 4 - trigger at 1Hz
tim.callback(tick) # set the callback to our tick function
tim = pyb.Timer(4) # create a timer object using timer 4
tim.init(mode=Timer.PERIODIC) # initialize it in periodic mode
tim_ch = tim.channel(Timer.A, freq=2) # configure channel A at a frequency of 2Hz
tim_ch.callback(handler=lambda t:led.toggle()) # toggle a LED on every cycle of the timer
Further examples::
Example using named function for the callback::
tim = pyb.Timer(4, freq=100) # freq in Hz
tim = pyb.Timer(4, prescaler=0, period=99)
tim.counter() # get counter (can also set)
tim.prescaler(2) # set prescaler (can also get)
tim.period(199) # set period (can also get)
tim.callback(lambda t: ...) # set callback for update interrupt (t=tim instance)
tim.callback(None) # clear callback
tim = Timer(1, mode=Timer.PERIODIC)
tim_a = tim.channel(Timer.A, freq=1000)
led = Pin('GPIO2', af=0, mode=Pin.OUT)
def tick(timer): # we will receive the timer object when being called
print(timer.time()) # show current timer's time value (is microseconds)
led.toggle() # toggle the LED
tim_a.callback(handler=tick)
Further examples::
tim1 = pyb.Timer(2, mode=Timer.EVENT_COUNT) # initialize it capture mode
tim2 = pyb.Timer(1, mode=Timer.PWM) # initialize it in PWM mode
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
tim_ch = tim2.channel(Timer.B, freq=10000, duty_cycle=50) # start the PWM on channel B with a 50% duty cycle
tim_ch.time() # get the current time in usec (can also be set)
tim_ch.freq(20) # set the frequency (can also get)
tim_ch.duty_cycle(30) # set the duty cycle to 30% (can also get)
tim_ch.duty_cycle(30, Timer.NEGATIVE) # set the duty cycle to 30% and change the polarity to negative
tim_ch.event_count() # get the number of captured events
tim_ch.event_time() # get the the time of the last captured event
tim_ch.period(2000000) # change the period to 2 seconds
*Note:* Timer 3 is reserved for internal use. Timer 5 controls
the servo driver, and Timer 6 is used for timed ADC/DAC reading/writing.
It is recommended to use the other timers in your programs.
*Note:* Memory can't be allocated during a callback (an interrupt) and so
exceptions raised within a callback don't give much information. See
:func:`micropython.alloc_emergency_exception_buf` for how to get around this
limitation.
Constructors
------------
.. class:: pyb.Timer(id, ...)
Construct a new timer object of the given id. If additional
arguments are given, then the timer is initialised by ``init(...)``.
``id`` can be 1 to 14, excluding 3.
.. only:: port_pyboard
Construct a new timer object of the given id. If additional
arguments are given, then the timer is initialised by ``init(...)``.
``id`` can be 1 to 14, excluding 3.
.. only:: port_wipy
Construct a new timer object of the given id. If additional
arguments are given, then the timer is initialised by ``init(...)``.
``id`` can be 1 to 4.
Methods
-------
.. method:: timer.callback(fun)
.. only:: port_pyboard
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.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.
.. method:: timer.init(\*, freq, prescaler, period)
Initialise the timer. Initialisation must be either by frequency (in Hz)
or by prescaler and period::
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)
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:
- ``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).

View File

@ -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

View File

@ -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

View File

@ -1,6 +1,4 @@
.. only:: port_pyboard
.. _quickref:
.. _quickref:
Quick reference for the pyboard
===============================

View File

@ -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
------------------

View File

@ -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()