Solved
Driving DAC from circular buffer using DMA and TIM - why is it not working?
As the title says, I've got a (circular) buffer of uint16_t values that I want to send to the DAC every time the timer updates. It seems like it's 95% working, in that if I manually trigger the DAC:
for (int i = 0; i < 10000; ++i)
{
LL_DAC_TrigSWConversion(DAC1, LL_DAC_CHANNEL_1);
HAL_Delay(1);
}I can see my waveform on the output pin. But when I try to have the DMA send the values to the DAC, the output never changes.
One complication is that I need to run in two modes - in one mode I'm taking the ADC input, processing it, and sending that to the DAC, in the other mode (I'm calling "inject" mode) the ADC is ignored and the DAC values come from my memory buffer.
The code to switch between modes looks like this:
if (inject && !Inject)
{
// Turn on inject mode
// HAL_DAC_Start_DMA(&hdac1, DAC_CHANNEL_1, (uint32_t*)Transfer, 4096, DAC_ALIGN_12B_R);
LL_DMA_DisableChannel(DMA1, LL_DMA_CHANNEL_3);
while (LL_DMA_IsEnabledChannel(DMA1, LL_DMA_CHANNEL_3)); // Wait till off
LL_DAC_Disable(DAC1, LL_DAC_CHANNEL_1);
//
LL_DAC_ClearFlag_DMAUDR1(DAC1);
LL_DMA_ClearFlag_TC3(DMA1);
LL_DMA_ClearFlag_HT3(DMA1);
LL_DMA_ClearFlag_TE3(DMA1);
//
LL_DAC_SetTriggerSource(DAC1, LL_DAC_CHANNEL_1, LL_DAC_TRIG_EXT_TIM4_TRGO);
LL_DAC_EnableTrigger(DAC1, LL_DAC_CHANNEL_1);
//
LL_DMA_SetDataTransferDirection(DMA1, LL_DMA_CHANNEL_3, LL_DMA_DIRECTION_MEMORY_TO_PERIPH);
LL_DMA_SetMode(DMA1, LL_DMA_CHANNEL_3, LL_DMA_MODE_CIRCULAR);
LL_DMA_SetPeriphIncMode(DMA1, LL_DMA_CHANNEL_3, LL_DMA_PERIPH_NOINCREMENT);
LL_DMA_SetMemoryIncMode(DMA1, LL_DMA_CHANNEL_3, LL_DMA_MEMORY_INCREMENT);
LL_DMA_SetPeriphSize(DMA1, LL_DMA_CHANNEL_3, LL_DMA_PDATAALIGN_HALFWORD);
LL_DMA_SetMemorySize(DMA1, LL_DMA_CHANNEL_3, LL_DMA_MDATAALIGN_HALFWORD);
LL_DMA_SetPeriphAddress(DMA1, LL_DMA_CHANNEL_3, (uint32_t)&DAC1->DHR12R1);
LL_DMA_SetMemoryAddress(DMA1, LL_DMA_CHANNEL_3, (uint32_t)Transfer);
LL_DMA_SetDataLength(DMA1, LL_DMA_CHANNEL_3, 4096);
// Enable DMA request on DAC channel
LL_DAC_EnableDMAReq(DAC1, LL_DAC_CHANNEL_1);
// Enable DMA channel
LL_DMA_EnableChannel(DMA1, LL_DMA_CHANNEL_3);
LL_DAC_Enable(DAC1, LL_DAC_CHANNEL_1);
//
LL_TIM_SetTriggerOutput(TIM4, LL_TIM_TRGO_UPDATE);
// LL_DAC_TrigSWConversion(DAC1, LL_DAC_CHANNEL_1);
//
/*
for (int i = 0; i < 10000; ++i)
{
LL_DAC_TrigSWConversion(DAC1, LL_DAC_CHANNEL_1);
HAL_Delay(1);
}
*/
Inject = inject;
}
else if ((!inject) && Inject)
{
// Turn off inject mode
LL_DAC_SetTriggerSource(DAC1, LL_DAC_CHANNEL_1, LL_DAC_TRIG_SOFTWARE);
LL_DAC_DisableTrigger(DAC1, LL_DAC_CHANNEL_1);
// LL_DAC_Disable(DAC1, LL_DAC_CHANNEL_1);
//
LL_DAC_DisableDMAReq(DAC1, LL_DAC_CHANNEL_1);
LL_DMA_DisableChannel(DMA1, LL_DMA_CHANNEL_3);
//
Inject = inject;
}Here are the init functions created from the IOC file:
static void MX_DMA_Init(void)
{
/* DMA controller clock enable */
__HAL_RCC_DMAMUX1_CLK_ENABLE();
__HAL_RCC_DMA1_CLK_ENABLE();
/* DMA interrupt init */
/* DMA1_Channel1_IRQn interrupt configuration */
HAL_NVIC_SetPriority(DMA1_Channel1_IRQn, 0, 0);
HAL_NVIC_EnableIRQ(DMA1_Channel1_IRQn);
}
static void MX_TIM4_Init(void)
{
/* USER CODE BEGIN TIM4_Init 0 */
/* USER CODE END TIM4_Init 0 */
TIM_ClockConfigTypeDef sClockSourceConfig = {0};
TIM_MasterConfigTypeDef sMasterConfig = {0};
/* USER CODE BEGIN TIM4_Init 1 */
/* USER CODE END TIM4_Init 1 */
htim4.Instance = TIM4;
htim4.Init.Prescaler = 239;
htim4.Init.CounterMode = TIM_COUNTERMODE_UP;
htim4.Init.Period = 10;
htim4.Init.ClockDivision = TIM_CLOCKDIVISION_DIV1;
htim4.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE;
if (HAL_TIM_Base_Init(&htim4) != HAL_OK)
{
Error_Handler();
}
sClockSourceConfig.ClockSource = TIM_CLOCKSOURCE_INTERNAL;
if (HAL_TIM_ConfigClockSource(&htim4, &sClockSourceConfig) != HAL_OK)
{
Error_Handler();
}
sMasterConfig.MasterOutputTrigger = TIM_TRGO_UPDATE;
sMasterConfig.MasterSlaveMode = TIM_MASTERSLAVEMODE_DISABLE;
if (HAL_TIMEx_MasterConfigSynchronization(&htim4, &sMasterConfig) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN TIM4_Init 2 */
/* USER CODE END TIM4_Init 2 */
}
static void MX_DAC1_Init(void)
{
/* USER CODE BEGIN DAC1_Init 0 */
/* USER CODE END DAC1_Init 0 */
DAC_ChannelConfTypeDef sConfig = {0};
/* USER CODE BEGIN DAC1_Init 1 */
/* USER CODE END DAC1_Init 1 */
/** DAC Initialization
*/
hdac1.Instance = DAC1;
if (HAL_DAC_Init(&hdac1) != HAL_OK)
{
Error_Handler();
}
/** DAC channel OUT1 config
*/
sConfig.DAC_HighFrequency = DAC_HIGH_FREQUENCY_INTERFACE_MODE_AUTOMATIC;
sConfig.DAC_DMADoubleDataMode = DISABLE;
sConfig.DAC_SignedFormat = DISABLE;
sConfig.DAC_SampleAndHold = DAC_SAMPLEANDHOLD_DISABLE;
sConfig.DAC_Trigger = DAC_TRIGGER_T4_TRGO;
sConfig.DAC_Trigger2 = DAC_TRIGGER_NONE;
sConfig.DAC_OutputBuffer = DAC_OUTPUTBUFFER_ENABLE;
sConfig.DAC_ConnectOnChipPeripheral = DAC_CHIPCONNECT_EXTERNAL;
sConfig.DAC_UserTrimming = DAC_TRIMMING_FACTORY;
if (HAL_DAC_ConfigChannel(&hdac1, &sConfig, DAC_CHANNEL_1) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN DAC1_Init 2 */
/* USER CODE END DAC1_Init 2 */
}
static void MX_ADC1_Init(void)
{
/* USER CODE BEGIN ADC1_Init 0 */
/* USER CODE END ADC1_Init 0 */
ADC_MultiModeTypeDef multimode = {0};
ADC_ChannelConfTypeDef sConfig = {0};
/* USER CODE BEGIN ADC1_Init 1 */
/* USER CODE END ADC1_Init 1 */
/** Common config
*/
hadc1.Instance = ADC1;
hadc1.Init.ClockPrescaler = ADC_CLOCK_SYNC_PCLK_DIV2;
hadc1.Init.Resolution = ADC_RESOLUTION_12B;
hadc1.Init.DataAlign = ADC_DATAALIGN_RIGHT;
hadc1.Init.GainCompensation = 0;
hadc1.Init.ScanConvMode = ADC_SCAN_DISABLE;
hadc1.Init.EOCSelection = ADC_EOC_SINGLE_CONV;
hadc1.Init.LowPowerAutoWait = DISABLE;
hadc1.Init.ContinuousConvMode = DISABLE;
hadc1.Init.NbrOfConversion = 1;
hadc1.Init.DiscontinuousConvMode = DISABLE;
hadc1.Init.ExternalTrigConv = ADC_SOFTWARE_START;
hadc1.Init.ExternalTrigConvEdge = ADC_EXTERNALTRIGCONVEDGE_NONE;
hadc1.Init.DMAContinuousRequests = DISABLE;
hadc1.Init.Overrun = ADC_OVR_DATA_OVERWRITTEN;
hadc1.Init.OversamplingMode = DISABLE;
if (HAL_ADC_Init(&hadc1) != HAL_OK)
{
Error_Handler();
}
/** Configure the ADC multi-mode
*/
multimode.Mode = ADC_MODE_INDEPENDENT;
if (HAL_ADCEx_MultiModeConfigChannel(&hadc1, &multimode) != HAL_OK)
{
Error_Handler();
}
/** Configure Regular Channel
*/
sConfig.Channel = ADC_CHANNEL_1;
sConfig.Rank = ADC_REGULAR_RANK_1;
sConfig.SamplingTime = ADC_SAMPLETIME_2CYCLES_5;
sConfig.SingleDiff = ADC_SINGLE_ENDED;
sConfig.OffsetNumber = ADC_OFFSET_NONE;
sConfig.Offset = 0;
if (HAL_ADC_ConfigChannel(&hadc1, &sConfig) != HAL_OK)
{
Error_Handler();
}
/* USER CODE BEGIN ADC1_Init 2 */
/* USER CODE END ADC1_Init 2 */
}What am I doing wrong? Thanks for any help!