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Daniel Campora
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cc3200: Add period set method to the Timer class.
1 parent 4172056 commit 84d11b5

2 files changed

Lines changed: 75 additions & 35 deletions

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‎cc3200/mods/pybtimer.c‎

Lines changed: 74 additions & 35 deletions
Original file line numberDiff line numberDiff line change
@@ -69,14 +69,15 @@
6969
///
7070
/// tim1 = pyb.Timer(2, mode=Timer.EVENT_COUNT) # initialize it capture mode
7171
/// tim2 = pyb.Timer(1, mode=Timer.PWM) # initialize it in PWM mode
72-
/// tim_ch = tim1.channel(Timer.A, freq=1, polarity=Timer.POSITIVE) # start the PWM on channel B with a 50% duty cycle
73-
/// 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
72+
/// 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
73+
/// tim_ch = tim2.channel(Timer.B, freq=10000, duty_cycle=50) # start the PWM on channel B with a 50% duty cycle
7474
/// tim_ch.time() # get the current time in usec (can also be set)
7575
/// tim_ch.freq(20) # set the frequency (can also get)
7676
/// tim_ch.duty_cycle(30) # set the duty cycle to 30% (can also get)
7777
/// tim_ch.duty_cycle(30, Timer.NEGATIVE) # set the duty cycle to 30% and change the polarity to negative
7878
/// tim_ch.event_count() # get the number of captured events
7979
/// tim_ch.event_time() # get the the time of the last captured event
80+
/// tim_ch.period(2000000) # change the period to 2 seconds
8081
///
8182

8283
/******************************************************************************
@@ -104,6 +105,7 @@ typedef struct _pyb_timer_channel_obj_t {
104105
mp_obj_base_t base;
105106
struct _pyb_timer_obj_t *timer;
106107
uint32_t frequency;
108+
uint32_t period;
107109
uint16_t channel;
108110
uint8_t polarity;
109111
uint8_t duty_cycle;
@@ -208,20 +210,23 @@ STATIC void timer_disable (pyb_timer_obj_t *tim) {
208210
STATIC uint32_t compute_prescaler_period_and_match_value(pyb_timer_channel_obj_t *ch, uint32_t *period_out, uint32_t *match_out) {
209211
uint32_t maxcount = (ch->channel == (TIMER_A | TIMER_B)) ? 0xFFFFFFFF : 0xFFFF;
210212
uint32_t prescaler;
211-
uint32_t period = PYBTIMER_SRC_FREQ_HZ / ch->frequency;
213+
uint32_t period_c = (ch->frequency > 0) ? PYBTIMER_SRC_FREQ_HZ / ch->frequency : ((PYBTIMER_SRC_FREQ_HZ / 1000000) * ch->period);
212214

213-
period = MAX(1, period) - 1;
214-
prescaler = period >> 16;
215-
*period_out = period;
215+
period_c = MAX(1, period_c) - 1;
216+
if (period_c == 0) {
217+
goto error;
218+
}
219+
prescaler = period_c >> 16;
220+
*period_out = period_c;
216221
if (prescaler > 0xFF && maxcount == 0xFFFF) {
217222
goto error;
218223
}
219224
// check limit values for the duty cycle
220225
if (ch->duty_cycle == 0) {
221-
*match_out = period - 1;
226+
*match_out = period_c - 1;
222227
}
223228
else {
224-
*match_out = period - ((period * ch->duty_cycle) / 100);
229+
*match_out = period_c - ((period_c * ch->duty_cycle) / 100);
225230
}
226231
if ((ch->timer->config & 0x0F) == TIMER_CFG_A_PWM && (*match_out > 0xFFFF)) {
227232
goto error;
@@ -240,15 +245,15 @@ STATIC void timer_init (pyb_timer_obj_t *tim) {
240245

241246
STATIC void timer_channel_init (pyb_timer_channel_obj_t *ch) {
242247
// calculate the period, the prescaler and the match value
243-
uint32_t period;
248+
uint32_t period_c;
244249
uint32_t match;
245-
uint32_t prescaler = compute_prescaler_period_and_match_value(ch, &period, &match);
250+
uint32_t prescaler = compute_prescaler_period_and_match_value(ch, &period_c, &match);
246251

247252
// set the prescaler
248253
MAP_TimerPrescaleSet(ch->timer->timer, ch->channel, (prescaler < 0xFF) ? prescaler : 0);
249254

250255
// set the load value
251-
MAP_TimerLoadSet(ch->timer->timer, ch->channel, period);
256+
MAP_TimerLoadSet(ch->timer->timer, ch->channel, period_c);
252257

253258
// configure the pwm if we are in such mode
254259
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);
412417
///
413418
/// Keyword arguments:
414419
///
415-
/// - `freq` - specifies the frequency in Hz
416-
///
417-
/// - `polarity` - in PWM specifies the polarity of the pulse. In capture mode specifies the edge to capture.
418-
/// in order to capture on both negative and positive edges, make it = Timer.POSITIVE | Timer.NEGATIVE.
420+
/// - `freq` - specifies the frequency in Hz.
421+
/// - `period` - specifies the period in microseconds.
422+
/// - `polarity` - in PWM specifies the polarity of the pulse. In capture mode specifies the edge to capture.
423+
/// in order to capture on both negative and positive edges, make it = Timer.POSITIVE | Timer.NEGATIVE.
424+
/// - `duty_cycle` - sets the duty cycle value
419425
///
420426
STATIC mp_obj_t pyb_timer_channel(mp_uint_t n_args, const mp_obj_t *pos_args, mp_map_t *kw_args) {
421427
static const mp_arg_t allowed_args[] = {
422428
{ MP_QSTR_freq, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
429+
{ MP_QSTR_period, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
423430
{ MP_QSTR_polarity, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = PYBTIMER_POLARITY_POS} },
424431
{ MP_QSTR_duty_cycle, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = 0} },
425432
};
@@ -454,12 +461,16 @@ STATIC mp_obj_t pyb_timer_channel(mp_uint_t n_args, const mp_obj_t *pos_args, mp
454461
mp_arg_val_t args[MP_ARRAY_SIZE(allowed_args)];
455462
mp_arg_parse_all(n_args - 2, pos_args + 2, kw_args, MP_ARRAY_SIZE(allowed_args), allowed_args, args);
456463

457-
// check the frequency
458-
if (args[0].u_int <= 0) {
464+
// throw an exception if both frequency and period are given
465+
if (args[0].u_int != 0 && args[1].u_int != 0) {
466+
goto error;
467+
}
468+
// check that at least one of them has a valid value
469+
if (args[0].u_int <= 0 && args[1].u_int <= 0) {
459470
goto error;
460471
}
461-
// check that the polarity is not both in pwm mode
462-
if ((tim->config & TIMER_A) == TIMER_CFG_A_PWM && args[1].u_int == (PYBTIMER_POLARITY_POS | PYBTIMER_POLARITY_NEG)) {
472+
// check that the polarity is not 'both' in pwm mode
473+
if ((tim->config & TIMER_A) == TIMER_CFG_A_PWM && args[2].u_int == (PYBTIMER_POLARITY_POS | PYBTIMER_POLARITY_NEG)) {
463474
goto error;
464475
}
465476

@@ -471,8 +482,9 @@ STATIC mp_obj_t pyb_timer_channel(mp_uint_t n_args, const mp_obj_t *pos_args, mp
471482

472483
// get the frequency the polarity and the duty cycle
473484
ch->frequency = args[0].u_int;
474-
ch->polarity = args[1].u_int;
475-
ch->duty_cycle = MIN(100, MAX(0, args[2].u_int));
485+
ch->period = args[1].u_int;
486+
ch->polarity = args[2].u_int;
487+
ch->duty_cycle = MIN(100, MAX(0, args[3].u_int));
476488

477489
timer_channel_init(ch);
478490

@@ -611,39 +623,65 @@ STATIC mp_obj_t pyb_timer_channel_freq(mp_uint_t n_args, const mp_obj_t *args) {
611623
return mp_obj_new_int(ch->frequency);
612624
} else {
613625
// set
614-
ch->frequency = mp_obj_get_int(args[1]);
626+
int32_t _frequency = mp_obj_get_int(args[1]);
627+
if (_frequency <= 0) {
628+
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, mpexception_value_invalid_arguments));
629+
}
630+
ch->frequency = _frequency;
631+
ch->period = 1000000 / _frequency;
615632
timer_channel_init(ch);
616633
return mp_const_none;
617634
}
618635
}
619636
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_timer_channel_freq_obj, 1, 2, pyb_timer_channel_freq);
620637

638+
/// \method period([value])
639+
/// get or set the period of the timer channel in microseconds
640+
STATIC mp_obj_t pyb_timer_channel_period(mp_uint_t n_args, const mp_obj_t *args) {
641+
pyb_timer_channel_obj_t *ch = args[0];
642+
if (n_args == 1) {
643+
// get
644+
return mp_obj_new_int(ch->period);
645+
} else {
646+
// set
647+
int32_t _period = mp_obj_get_int(args[1]);
648+
if (_period <= 0) {
649+
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, mpexception_value_invalid_arguments));
650+
}
651+
ch->period = _period;
652+
ch->frequency = 1000000 / _period;
653+
timer_channel_init(ch);
654+
return mp_const_none;
655+
}
656+
}
657+
STATIC MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(pyb_timer_channel_period_obj, 1, 2, pyb_timer_channel_period);
658+
621659
/// \method time([value])
622660
/// get or set the value of the timer channel in microseconds
623661
STATIC mp_obj_t pyb_timer_channel_time(mp_uint_t n_args, const mp_obj_t *args) {
624662
pyb_timer_channel_obj_t *ch = args[0];
625663
uint32_t value;
626664
// calculate the period, the prescaler and the match value
627-
uint32_t period;
665+
uint32_t period_c;
628666
uint32_t match;
629-
(void)compute_prescaler_period_and_match_value(ch, &period, &match);
667+
(void)compute_prescaler_period_and_match_value(ch, &period_c, &match);
630668
if (n_args == 1) {
631669
// get
632670
value = (ch->channel == TIMER_B) ? HWREG(ch->timer->timer + TIMER_O_TBV) : HWREG(ch->timer->timer + TIMER_O_TAV);
633671
// return the current timer value in microseconds
634672
// substract value to period since we are always operating in count-down mode
635-
uint32_t time_t = (1000 * (period - value)) / period;
673+
uint32_t time_t = (1000 * (period_c - value)) / period_c;
636674
return mp_obj_new_int((time_t * 1000) / ch->frequency);
637675
}
638676
else {
639677
// set
640-
value = (mp_obj_get_int(args[1]) * ((ch->frequency * period) / 1000)) / 1000;
678+
value = (mp_obj_get_int(args[1]) * ((ch->frequency * period_c) / 1000)) / 1000;
641679
if ((value > 0xFFFF) && (ch->timer->config & TIMER_CFG_SPLIT_PAIR)) {
642680
// this exceeds the maximum value of a 16-bit timer
643681
nlr_raise(mp_obj_new_exception_msg(&mp_type_ValueError, mpexception_value_invalid_arguments));
644682
}
645683
// write period minus value since we are always operating in count-down mode
646-
TimerValueSet (ch->timer->timer, ch->channel, (period - value));
684+
TimerValueSet (ch->timer->timer, ch->channel, (period_c - value));
647685
return mp_const_none;
648686
}
649687
}
@@ -662,12 +700,12 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_1(pyb_timer_channel_event_count_obj, pyb_timer_ch
662700
STATIC mp_obj_t pyb_timer_channel_event_time(mp_obj_t self_in) {
663701
pyb_timer_channel_obj_t *ch = self_in;
664702
// calculate the period, the prescaler and the match value
665-
uint32_t period;
703+
uint32_t period_c;
666704
uint32_t match;
667-
(void)compute_prescaler_period_and_match_value(ch, &period, &match);
705+
(void)compute_prescaler_period_and_match_value(ch, &period_c, &match);
668706
uint32_t value = MAP_TimerValueGet(ch->timer->timer, ch->channel == (TIMER_A | TIMER_B) ? TIMER_A : ch->channel);
669707
// substract value to period since we are always operating in count-down mode
670-
uint32_t time_t = (1000 * (period - value)) / period;
708+
uint32_t time_t = (1000 * (period_c - value)) / period_c;
671709
return mp_obj_new_int((time_t * 1000) / ch->frequency);
672710
}
673711
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
683721
else {
684722
// duty cycle must be converted from percentage to ticks
685723
// calculate the period, the prescaler and the match value
686-
uint32_t period;
724+
uint32_t period_c;
687725
uint32_t match;
688726
ch->duty_cycle = MIN(100, MAX(0, mp_obj_get_int(args[1])));
689-
compute_prescaler_period_and_match_value(ch, &period, &match);
727+
compute_prescaler_period_and_match_value(ch, &period_c, &match);
690728
if (n_args == 3) {
691729
// set the new polarity if requested
692730
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
801839
ch->duty_cycle = MIN(100, c_value);
802840

803841
// reload the timer
804-
uint32_t period;
842+
uint32_t period_c;
805843
uint32_t match;
806-
compute_prescaler_period_and_match_value(ch, &period, &match);
807-
MAP_TimerLoadSet(ch->timer->timer, ch->channel, period);
844+
compute_prescaler_period_and_match_value(ch, &period_c, &match);
845+
MAP_TimerLoadSet(ch->timer->timer, ch->channel, period_c);
808846
// set the appropiate match value
809847
MAP_TimerMatchSet(ch->timer->timer, ch->channel, (_config == TIMER_CFG_A_PWM) ? match : c_value);
810848

@@ -821,6 +859,7 @@ STATIC MP_DEFINE_CONST_FUN_OBJ_KW(pyb_timer_channel_callback_obj, 1, pyb_timer_c
821859
STATIC const mp_map_elem_t pyb_timer_channel_locals_dict_table[] = {
822860
// instance methods
823861
{ MP_OBJ_NEW_QSTR(MP_QSTR_freq), (mp_obj_t)&pyb_timer_channel_freq_obj },
862+
{ MP_OBJ_NEW_QSTR(MP_QSTR_period), (mp_obj_t)&pyb_timer_channel_period_obj },
824863
{ MP_OBJ_NEW_QSTR(MP_QSTR_time), (mp_obj_t)&pyb_timer_channel_time_obj },
825864
{ MP_OBJ_NEW_QSTR(MP_QSTR_event_count), (mp_obj_t)&pyb_timer_channel_event_count_obj },
826865
{ MP_OBJ_NEW_QSTR(MP_QSTR_event_time), (mp_obj_t)&pyb_timer_channel_event_time_obj },

‎cc3200/qstrdefsport.h‎

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -336,6 +336,7 @@ Q(TimerChannel)
336336
Q(init)
337337
Q(deinit)
338338
Q(freq)
339+
Q(period)
339340
Q(mode)
340341
Q(width)
341342
Q(channel)

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