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[LPC1114] Fixed PwmOut spike pulse issue 

[LPC1114] Fixed PwmOut spike pulse issue when duty is 0%.
pull/371/head
Toyomasa Watarai 2014-06-24 13:28:40 +09:00
parent f5d3245fe9
commit 27a7514c6e
1 changed files with 9 additions and 2 deletions
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11
libraries/mbed/targets/hal/TARGET_NXP/TARGET_LPC11XX_11CXX/pwmout_api.c
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@ -109,11 +109,15 @@ void pwmout_write(pwmout_t* obj, float value) {
} else if (value > 1.0f) {
value = 1.0;
}
timer_mr tid = pwm_timer_map[obj->pwm];
LPC_TMR_TypeDef *timer = Timers[tid.timer];
uint32_t t_off = timer->MR3 - (uint32_t)((float)(timer->MR3) * value);
// to avoid spike pulse when duty is 0%
if (value == 0) {
t_off++;
}
timer->TCR = TCR_RESET;
timer->MR[tid.mr] = t_off;
timer->TCR = TCR_CNT_EN;
@ -124,6 +128,9 @@ float pwmout_read(pwmout_t* obj) {
LPC_TMR_TypeDef *timer = Timers[tid.timer];
float v = (float)(timer->MR3 - timer->MR[tid.mr]) / (float)(timer->MR3);
if (timer->MR[tid.mr] > timer->MR3) {
v = 0.0f;
}
return (v > 1.0f) ? (1.0f) : (v);
}