Kang mingyo / FastPWM

FASTPWM

Dependents:   OV7670_make

Device/FastPWM_STM_TIM.cpp@28:3c8a0d977bc3, 2016-02-29 (annotated)

Committer:
Sissors
Date:
Mon Feb 29 19:18:42 2016 +0000
Revision:
28:3c8a0d977bc3
Parent:
24:1f451660d8c0
Child:
32:e880dcb178f4
STM32F3, F4, L4, etc now use the channels number from the mbed library. The others still need to use the manual way.

Who changed what in which revision?

UserRevisionLine numberNew contents of line
Sissors 13:cdefd9d75b64 1 //This should (hopefully) work on all STM targets which use TIM timers for PWM
Sissors 13:cdefd9d75b64 2
Sissors 13:cdefd9d75b64 3 #ifdef TARGET_STM
Sissors 13:cdefd9d75b64 4
Sissors 13:cdefd9d75b64 5 #include "FastPWM.h"
Sissors 13:cdefd9d75b64 6
jocis 17:8378bc456f0d 7 typedef __IO uint32_t* CHANNEL_P_T;
jocis 17:8378bc456f0d 8
jocis 17:8378bc456f0d 9 #define PWM_CHANNEL (**(CHANNEL_P_T*)fast_obj)
Sissors 13:cdefd9d75b64 10 #define PWM_TIMER ((TIM_TypeDef*)_pwm.pwm)
Sissors 13:cdefd9d75b64 11
Sissors 28:3c8a0d977bc3 12 #if defined(TARGET_STM32F0) || defined (TARGET_STM32F1) || defined (TARGET_STM32L1)
Sissors 28:3c8a0d977bc3 13 extern __IO uint32_t* getChannel(TIM_TypeDef* pwm, PinName pin);
Sissors 28:3c8a0d977bc3 14 #endif
Sissors 13:cdefd9d75b64 15
Sissors 13:cdefd9d75b64 16 void FastPWM::initFastPWM( void ) {
jocis 17:8378bc456f0d 17 fast_obj = new (CHANNEL_P_T);
Sissors 28:3c8a0d977bc3 18
Sissors 28:3c8a0d977bc3 19 #if defined(TARGET_STM32F0) || defined (TARGET_STM32F1) || defined (TARGET_STM32L1)
jocis 17:8378bc456f0d 20 *(CHANNEL_P_T*)fast_obj = getChannel(PWM_TIMER, _pwm.pin);
Sissors 28:3c8a0d977bc3 21 #else
Sissors 28:3c8a0d977bc3 22 *(CHANNEL_P_T*)fast_obj = &PWM_TIMER->CCR1 + _pwm.channel - 1;
Sissors 28:3c8a0d977bc3 23 #endif
jocis 17:8378bc456f0d 24
Sissors 22:db9c0cf445e2 25 //Enable PWM period syncing for glitch free result
Sissors 22:db9c0cf445e2 26 PWM_TIMER->CR1 |= TIM_CR1_ARPE;
Sissors 22:db9c0cf445e2 27
Sissors 13:cdefd9d75b64 28 bits = 16;
Sissors 13:cdefd9d75b64 29 }
Sissors 13:cdefd9d75b64 30
Sissors 13:cdefd9d75b64 31 void FastPWM::pulsewidth_ticks( uint32_t ticks ) {
Sissors 13:cdefd9d75b64 32 PWM_CHANNEL = ticks;
Sissors 13:cdefd9d75b64 33 }
Sissors 13:cdefd9d75b64 34
Sissors 13:cdefd9d75b64 35 void FastPWM::period_ticks( uint32_t ticks ) {
Sissors 13:cdefd9d75b64 36 PWM_TIMER->ARR = ticks - 1;
Sissors 13:cdefd9d75b64 37 }
Sissors 13:cdefd9d75b64 38
Sissors 13:cdefd9d75b64 39 uint32_t FastPWM::getPeriod( void ) {
Sissors 13:cdefd9d75b64 40 return PWM_TIMER->ARR + 1;
Sissors 13:cdefd9d75b64 41 }
Sissors 13:cdefd9d75b64 42
Sissors 13:cdefd9d75b64 43 uint32_t FastPWM::setPrescaler(uint32_t reqScale) {
Sissors 13:cdefd9d75b64 44 if (reqScale == 0)
Sissors 13:cdefd9d75b64 45 //Return prescaler
Sissors 13:cdefd9d75b64 46 return PWM_TIMER->PSC + 1;
Sissors 13:cdefd9d75b64 47 if (reqScale > (uint32_t)(1<<16))
Sissors 13:cdefd9d75b64 48 reqScale = 1<<16;
Sissors 13:cdefd9d75b64 49 //Else set prescaler, we have to substract one from reqScale since a 0 in PCVAL is prescaler of 1
Sissors 13:cdefd9d75b64 50 PWM_TIMER->PSC = reqScale - 1;
Sissors 13:cdefd9d75b64 51
Sissors 13:cdefd9d75b64 52 return reqScale;
Sissors 13:cdefd9d75b64 53 }
Sissors 13:cdefd9d75b64 54
Sissors 13:cdefd9d75b64 55 #endif