I have STM32F103 working on 8MHz. Use new ST HAL Driver (STM32CubeMX) + MDK-ARM v5.17? If I Init PWM on Ch1 Tim3
void MX_TIM3_Init(void) { TIM_ClockConfigTypeDef sClockSourceConfig; TIM_MasterConfigTypeDef sMasterConfig; TIM_OC_InitTypeDef sConfigOC; htim3.Instance = TIM3; htim3.Init.Prescaler = 0; htim3.Init.CounterMode = TIM_COUNTERMODE_UP; htim3.Init.Period = 9; htim3.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1; HAL_TIM_Base_Init(&htim3); sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL; HAL_TIM_ConfigClockSource(&htim3, &sClockSourceConfig); HAL_TIM_PWM_Init(&htim3); sMasterConfig.MasterOutputTrigger = TIM_TRGO_RESET; sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE; HAL_TIMEx_MasterConfigSynchronization(&htim3, &sMasterConfig); sConfigOC.OCMode = TIM_OCMODE_PWM1; sConfigOC.Pulse = 1; sConfigOC.OCPolarity = TIM_OCPOLARITY_HIGH; sConfigOC.OCFastMode = TIM_OCFAST_DISABLE; HAL_TIM_PWM_ConfigChannel(&htim3, &sConfigOC, TIM_CHANNEL_1); } ... // Start PWM HAL_TIM_PWM_Start_IT(&htim3, TIM_CHANNEL_1);
all working OK and output generate 125ns pulse on 800kHz (1.25us) If replace Start_IT with DMA version
uint32_t pData[1]={6}; HAL_TIM_PWM_Start_DMA(&htim3, TIM_CHANNEL_1,pData,1);
all working OK and output generate 700ns pulse on 800kHz (1.25us),but if use
uint32_t pData[16]={3,3,3,3,3,3,3,3,0,0,0,0,0,0,0,0}; HAL_TIM_PWM_Start_DMA(&htim3, TIM_CHANNEL_1,pData,16);
this genreate 375ns its OK but frequency is 400kHz (2,5us) If I trace and look on reg CCR1 I see 3,0,3,0,3,0,3,0,3,0,3,0,3,0,3,0 What's wrong, what's the problem? Why is inserted 0 between 3?
Complementing: I found another datasheet for WS2812B,it contains slightly different timings. http://goo.gl/oONsSQ The Chinese are great magician on datasheet. Maybe the problem is only the timing Log 1
Other additions
Period (ARR) = (Frequency of counter / required frequency)-1 Period (ARR) = (8MHz / 800kHz)-1 Period (ARR) = 9
I find problem
... // STM32F103ZE Clock 8MHz htim3.Init.Period = 9; ... // G G G G G G G G R R R R R R R R B B B B B B B B // 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 uint16_t pData[25]={3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,3,6,6,6,6,6,6,6,6,0}; // --------0------ --------0------ ------256------ STOP HAL_TIM_PWM_Start_DMA(&htim3, TIM_CHANNEL_1,(uint32_t*)pData,25);
and HW logic analyzer show this: http://imgur.com/QQclNlq
Instead of 16 ZERO bit is generate 19 ZERO bit and instead of 8 ONE bit is generate 9 ONE bit
Suspect someone in what could be the problem?