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cc3200: Add period set method to the Timer class.

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This commit is contained in:
Daniel Campora 2015-05-29 15:47:07 +02:00
parent 417205623a
commit 84d11b5e53
2 changed files with 75 additions and 35 deletions
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109
cc3200/mods/pybtimer.c
View File

@ -69,14 +69,15 @@
///
/// 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 PWM on channel B with a 50% duty cycle
/// tim_ch = tim2.channel(Timer.B, freq=10000, duty_cycle=50) # start the event counter with a frequency of 1Hz and triggered by positive edges
/// 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
///
/******************************************************************************
@ -104,6 +105,7 @@ typedef struct _pyb_timer_channel_obj_t {
mp_obj_base_t base;
struct _pyb_timer_obj_t *timer;
uint32_t frequency;
uint32_t period;
uint16_t channel;
uint8_t polarity;
uint8_t duty_cycle;
@ -208,20 +210,23 @@ STATIC void timer_disable (pyb_timer_obj_t *tim) {
STATIC uint32_t compute_prescaler_period_and_match_value(pyb_timer_channel_obj_t *ch, uint32_t *period_out, uint32_t *match_out) {
uint32_t maxcount = (ch->channel == (TIMER_A | TIMER_B)) ? 0xFFFFFFFF : 0xFFFF;
uint32_t prescaler;
uint32_t period = PYBTIMER_SRC_FREQ_HZ / ch->frequency;
uint32_t period_c = (ch->frequency > 0) ? PYBTIMER_SRC_FREQ_HZ / ch->frequency : ((PYBTIMER_SRC_FREQ_HZ / 1000000) * ch->period);
period = MAX(1, period) - 1;
prescaler = period >> 16;
*period_out = period;
period_c = MAX(1, period_c) - 1;
if (period_c == 0) {
goto error;
}
prescaler = period_c >> 16;
*period_out = period_c;
if (prescaler > 0xFF && maxcount == 0xFFFF) {
goto error;
}
// check limit values for the duty cycle
if (ch->duty_cycle == 0) {
*match_out = period - 1;
*match_out = period_c - 1;
}
else {
*match_out = period - ((period * ch->duty_cycle) / 100);
*match_out = period_c - ((period_c * ch->duty_cycle) / 100);
}
if ((ch->timer->config & 0x0F) == TIMER_CFG_A_PWM && (*match_out > 0xFFFF)) {
goto error;
@ -240,15 +245,15 @@ STATIC void timer_init (pyb_timer_obj_t *tim) {
STATIC void timer_channel_init (pyb_timer_channel_obj_t *ch) {
// calculate the period, the prescaler and the match value
uint32_t period;
uint32_t period_c;
uint32_t match;
uint32_t prescaler = compute_prescaler_period_and_match_value(ch, &period, &match);
uint32_t prescaler = compute_prescaler_period_and_match_value(ch, &period_c, &match);
// set the prescaler
MAP_TimerPrescaleSet(ch->timer->timer, ch->channel, (prescaler < 0xFF) ? prescaler : 0);
// set the load value
MAP_TimerLoadSet(ch->timer->timer, ch->channel, period);
MAP_TimerLoadSet(ch->timer->timer, ch->channel, period_c);
// configure the pwm if we are in such mode
if ((ch->timer->config & 0x0F) == TIMER_CFG_A_PWM) {
@ -412,14 +417,16 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_timer_deinit_obj, pyb_timer_deinit);
///
/// Keyword arguments:
///
/// - `freq` - specifies the frequency in Hz
///
/// - `polarity` - in PWM specifies the polarity of the pulse. In capture mode specifies the edge to capture.
/// in order to capture on both negative and positive edges, make it = Timer.POSITIVE | Timer.NEGATIVE.
/// - `freq` - specifies the frequency in Hz.
/// - `period` - specifies the period in microseconds.
/// - `polarity` - in PWM specifies the polarity of the pulse. In capture mode specifies the edge to capture.
/// in order to capture on both negative and positive edges, make it = Timer.POSITIVE | Timer.NEGATIVE.
/// - `duty_cycle` - sets the duty cycle value
///
STATIC mp_obj_t pyb_timer_channel(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_freq, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_period, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
{ MP_QSTR_polarity, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = PYBTIMER_POLARITY_POS} },
{ MP_QSTR_duty_cycle, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
};
@ -454,12 +461,16 @@ STATIC mp_obj_t pyb_timer_channel(mp_uint_t n_args, const mp_obj_t *pos_args, mp
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
mp_arg_parse_all(n_args - 2, pos_args + 2, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
// check the frequency
if (args[0].u_int <= 0) {
// throw an exception if both frequency and period are given
if (args[0].u_int != 0 && args[1].u_int != 0) {
goto error;
}
// check that the polarity is not both in pwm mode
if ((tim->config & TIMER_A) == TIMER_CFG_A_PWM && args[1].u_int == (PYBTIMER_POLARITY_POS | PYBTIMER_POLARITY_NEG)) {
// check that at least one of them has a valid value
if (args[0].u_int <= 0 && args[1].u_int <= 0) {
goto error;
}
// check that the polarity is not 'both' in pwm mode
if ((tim->config & TIMER_A) == TIMER_CFG_A_PWM && args[2].u_int == (PYBTIMER_POLARITY_POS | PYBTIMER_POLARITY_NEG)) {
goto error;
}
@ -471,8 +482,9 @@ STATIC mp_obj_t pyb_timer_channel(mp_uint_t n_args, const mp_obj_t *pos_args, mp
// get the frequency the polarity and the duty cycle
ch->frequency = args[0].u_int;
ch->polarity = args[1].u_int;
ch->duty_cycle = MIN(100, MAX(0, args[2].u_int));
ch->period = args[1].u_int;
ch->polarity = args[2].u_int;
ch->duty_cycle = MIN(100, MAX(0, args[3].u_int));
timer_channel_init(ch);
@ -611,39 +623,65 @@ STATIC mp_obj_t pyb_timer_channel_freq(mp_uint_t n_args, const mp_obj_t *args) {
return mp_obj_new_int(ch->frequency);
} else {
// set
ch->frequency = mp_obj_get_int(args[1]);
int32_t _frequency = mp_obj_get_int(args[1]);
if (_frequency <= 0) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, mpexception_value_invalid_arguments));
}
ch->frequency = _frequency;
ch->period = 1000000 / _frequency;
timer_channel_init(ch);
return mp_const_none;
}
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_timer_channel_freq_obj, 1, 2, pyb_timer_channel_freq);
/// \method period([value])
/// get or set the period of the timer channel in microseconds
STATIC mp_obj_t pyb_timer_channel_period(mp_uint_t n_args, const mp_obj_t *args) {
pyb_timer_channel_obj_t *ch = args[0];
if (n_args == 1) {
// get
return mp_obj_new_int(ch->period);
} else {
// set
int32_t _period = mp_obj_get_int(args[1]);
if (_period <= 0) {
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, mpexception_value_invalid_arguments));
}
ch->period = _period;
ch->frequency = 1000000 / _period;
timer_channel_init(ch);
return mp_const_none;
}
}
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_timer_channel_period_obj, 1, 2, pyb_timer_channel_period);
/// \method time([value])
/// get or set the value of the timer channel in microseconds
STATIC mp_obj_t pyb_timer_channel_time(mp_uint_t n_args, const mp_obj_t *args) {
pyb_timer_channel_obj_t *ch = args[0];
uint32_t value;
// calculate the period, the prescaler and the match value
uint32_t period;
uint32_t period_c;
uint32_t match;
(void)compute_prescaler_period_and_match_value(ch, &period, &match);
(void)compute_prescaler_period_and_match_value(ch, &period_c, &match);
if (n_args == 1) {
// get
value = (ch->channel == TIMER_B) ? HWREG(ch->timer->timer + TIMER_O_TBV) : HWREG(ch->timer->timer + TIMER_O_TAV);
// return the current timer value in microseconds
// substract value to period since we are always operating in count-down mode
uint32_t time_t = (1000 * (period - value)) / period;
uint32_t time_t = (1000 * (period_c - value)) / period_c;
return mp_obj_new_int((time_t * 1000) / ch->frequency);
}
else {
// set
value = (mp_obj_get_int(args[1]) * ((ch->frequency * period) / 1000)) / 1000;
value = (mp_obj_get_int(args[1]) * ((ch->frequency * period_c) / 1000)) / 1000;
if ((value > 0xFFFF) && (ch->timer->config & TIMER_CFG_SPLIT_PAIR)) {
// this exceeds the maximum value of a 16-bit timer
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, mpexception_value_invalid_arguments));
}
// write period minus value since we are always operating in count-down mode
TimerValueSet (ch->timer->timer, ch->channel, (period - value));
TimerValueSet (ch->timer->timer, ch->channel, (period_c - value));
return mp_const_none;
}
}
@ -662,12 +700,12 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_timer_channel_event_count_obj, pyb_timer_ch
STATIC mp_obj_t pyb_timer_channel_event_time(mp_obj_t self_in) {
pyb_timer_channel_obj_t *ch = self_in;
// calculate the period, the prescaler and the match value
uint32_t period;
uint32_t period_c;
uint32_t match;
(void)compute_prescaler_period_and_match_value(ch, &period, &match);
(void)compute_prescaler_period_and_match_value(ch, &period_c, &match);
uint32_t value = MAP_TimerValueGet(ch->timer->timer, ch->channel == (TIMER_A | TIMER_B) ? TIMER_A : ch->channel);
// substract value to period since we are always operating in count-down mode
uint32_t time_t = (1000 * (period - value)) / period;
uint32_t time_t = (1000 * (period_c - value)) / period_c;
return mp_obj_new_int((time_t * 1000) / ch->frequency);
}
STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_timer_channel_event_time_obj, pyb_timer_channel_event_time);
@ -683,10 +721,10 @@ STATIC mp_obj_t pyb_timer_channel_duty_cycle(mp_uint_t n_args, const mp_obj_t *a
else {
// duty cycle must be converted from percentage to ticks
// calculate the period, the prescaler and the match value
uint32_t period;
uint32_t period_c;
uint32_t match;
ch->duty_cycle = MIN(100, MAX(0, mp_obj_get_int(args[1])));
compute_prescaler_period_and_match_value(ch, &period, &match);
compute_prescaler_period_and_match_value(ch, &period_c, &match);
if (n_args == 3) {
// set the new polarity if requested
ch->polarity = mp_obj_get_int(args[2]);
@ -801,10 +839,10 @@ STATIC mp_obj_t pyb_timer_channel_callback (mp_uint_t n_args, const mp_obj_t *po
ch->duty_cycle = MIN(100, c_value);
// reload the timer
uint32_t period;
uint32_t period_c;
uint32_t match;
compute_prescaler_period_and_match_value(ch, &period, &match);
MAP_TimerLoadSet(ch->timer->timer, ch->channel, period);
compute_prescaler_period_and_match_value(ch, &period_c, &match);
MAP_TimerLoadSet(ch->timer->timer, ch->channel, period_c);
// set the appropiate match value
MAP_TimerMatchSet(ch->timer->timer, ch->channel, (_config == TIMER_CFG_A_PWM) ? match : c_value);
@ -821,6 +859,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_timer_channel_callback_obj, 1, pyb_timer_c
STATIC const mp_map_elem_t pyb_timer_channel_locals_dict_table[] = {
// instance methods
{ MP_OBJ_NEW_QSTR(MP_QSTR_freq), (mp_obj_t)&pyb_timer_channel_freq_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_period), (mp_obj_t)&pyb_timer_channel_period_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_time), (mp_obj_t)&pyb_timer_channel_time_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_event_count), (mp_obj_t)&pyb_timer_channel_event_count_obj },
{ MP_OBJ_NEW_QSTR(MP_QSTR_event_time), (mp_obj_t)&pyb_timer_channel_event_time_obj },

1
cc3200/qstrdefsport.h
View File

@ -336,6 +336,7 @@ Q(TimerChannel)
Q(init)
Q(deinit)
Q(freq)
Q(period)
Q(mode)
Q(width)
Q(channel)