HAL Timer Triggered SPI Transfer

[ferrario]

Posted on June 27, 2016 at 17:02

I am trying to transfer data to spi using timer 3 as a time base.

Timer 3 works fine.

Than I am using :

DMA1 Stream2 Channel5 to trigger

memory to SPI2->DR transfers, with no joy.

//TIMER 3 CHANNEL 4 UPDATE

hdma_tim3_ch4_up.Instance = DMA1_Stream2;

hdma_tim3_ch4_up.Init.Channel = DMA_CHANNEL_5;

hdma_tim3_ch4_up.Init.Direction = DMA_MEMORY_TO_PERIPH;

hdma_tim3_ch4_up.Init.PeriphInc = DMA_PINC_DISABLE;

hdma_tim3_ch4_up.Init.MemInc = DMA_MINC_DISABLE;

hdma_tim3_ch4_up.Init.PeriphDataAlignment = DMA_PDATAALIGN_HALFWORD;

hdma_tim3_ch4_up.Init.MemDataAlignment = DMA_MDATAALIGN_HALFWORD;

hdma_tim3_ch4_up.Init.Mode = DMA_CIRCULAR;

hdma_tim3_ch4_up.Init.Priority = DMA_PRIORITY_LOW;

hdma_tim3_ch4_up.Init.FIFOMode = DMA_FIFOMODE_DISABLE;

HAL_DMA_Init(&hdma_tim3_ch4_up);

/* Several peripheral DMA handle pointers point to the same DMA handle.

Be aware that there is only one stream to perform all the requested DMAs. */

__HAL_LINKDMA(htim_base,hdma[TIM_DMA_ID_CC4],hdma_tim3_ch4_up);

__HAL_LINKDMA(htim_base,hdma[TIM_DMA_ID_UPDATE],hdma_tim3_ch4_up);

/**MAIN.c*********************/

DMA_HandleTypeDef hdma_tim3_ch4_up;

HAL_TIM_OC_Start(&htim3, TIM_CHANNEL_4); //start timer 4, works

HAL_DMA_Start_IT(&hdma_tim3_ch4_up, (uint32_t*)&SV.fields.internal_current, (uint32_t*)(&(SPI2->DR)), 1);

__HAL_TIM_ENABLE_DMA(&htim3, TIM_DMA_UPDATE); //TIM1 trigger DMA transfer

Still no data on the spi bus.

[Tesla DeLorean]

Posted on June 27, 2016 at 19:42

__HAL_LINKDMA(htim_base,hdma[TIM_DMA_ID_CC4],hdma_tim3_ch4_up);
__HAL_LINKDMA(htim_base,hdma[TIM_DMA_ID_UPDATE],hdma_tim3_ch4_up);

Decide if you are using UPDATE or CC4 (CHANNEL 4) as the trigger, you get to pick ONE, then apply consistently

[ferrario]

Posted on June 28, 2016 at 17:42

Thanks Clive,

it works like a charm.

The combination of PWM generation on CH1 and fine delay generation with the update event allows for /CS generation on the SPI Bus.

Fabio

[patmcc]

Posted on July 02, 2016 at 00:09

Hi Fabio,

I'm trying to control SPI writes using a timer as well. Can you post the complete working code?

-Pat