From 84d11b5e5341a008405f210892543696df963454 Mon Sep 17 00:00:00 2001
From: Daniel Campora <daniel@wipy.io>
Date: Fri, 29 May 2015 15:47:07 +0200
Subject: [PATCH] cc3200: Add period set method to the Timer class.
---
cc3200/mods/pybtimer.c | 109 ++++++++++++++++++++++++++++-------------
cc3200/qstrdefsport.h | 1 +
2 files changed, 75 insertions(+), 35 deletions(-)
diff --git a/cc3200/mods/pybtimer.c b/cc3200/mods/pybtimer.c
index f8069dc48..23299d5f9 100644
--- a/cc3200/mods/pybtimer.c
+++ b/cc3200/mods/pybtimer.c
@@ -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 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[1].u_int == (PYBTIMER_POLARITY_POS | PYBTIMER_POLARITY_NEG)) {
+ // 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 },
diff --git a/cc3200/qstrdefsport.h b/cc3200/qstrdefsport.h
index 36c8430a3..30337e741 100644
--- a/cc3200/qstrdefsport.h
+++ b/cc3200/qstrdefsport.h
@@ -336,6 +336,7 @@ Q(TimerChannel)
Q(init)
Q(deinit)
Q(freq)
+Q(period)
Q(mode)
Q(width)
Q(channel)
--
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