STM8L1528 ADC, DMA, TImer not working together.
Hi there,
I am developing code for STM8L1528 EVAL board. My goal is to configure adc with dma(peripheral to memory) where adc should collect data for certain period, for example, 2 seconds.
So I configured adc and dma according to examples codes given. but I added TIM4 to stop ADC conversion after 1 seconds. My code stucks in TIM4 ISR. Is there anything I am forgetting?
Also, I configured ADC with 12 bit, fast channel 24, 4 cycles. But I am getting less sampling rate. Why is this happening? Thanks for the great help.
Below are my code snippets:
static void CLK_Config(void)
{
/* Select HSE as system clock source */
CLK_SYSCLKSourceSwitchCmd(ENABLE);
CLK_SYSCLKSourceConfig(CLK_SYSCLKSource_HSE);
/*High speed external clock prescaler: 1*/
CLK_SYSCLKDivConfig(CLK_SYSCLKDiv_1);
while (CLK_GetSYSCLKSource() != CLK_SYSCLKSource_HSE)
{}
/* Enable ADC1 clock */
CLK_PeripheralClockConfig(CLK_Peripheral_ADC1, ENABLE);
/* Enable DMA1 clock */
CLK_PeripheralClockConfig(CLK_Peripheral_DMA1, ENABLE);
/* Enable TIM1 clock */
//CLK_PeripheralClockConfig(CLK_Peripheral_TIM1, ENABLE);
/* Enable TIM4 CLK */
CLK_PeripheralClockConfig(CLK_Peripheral_TIM4, ENABLE); //tim4
}
static void ADC_Config(void)
{
/* Initialize and configure ADC1 */
ADC_Init(ADC1, ADC_ConversionMode_Single, ADC_Resolution_12Bit, ADC_Prescaler_1);
ADC_SamplingTimeConfig(ADC1, ADC_Group_FastChannels, ADC_SamplingTime_4Cycles);
/* Enable ADC1 */
ADC_Cmd(ADC1, ENABLE);
ADC_ChannelCmd(ADC1, ADC_Channel_24, ENABLE); /* connected to BNC */
}
static void DMA_Config(void)
{
/* Connect ADC to DMA channel 0 */
SYSCFG_REMAPDMAChannelConfig(REMAP_DMA1Channel_ADC1ToChannel0);
DMA_Init(DMA1_Channel0, BUFFER_ADDRESS,
ADC1_DR_ADDRESS,
BUFFER_SIZE,
DMA_DIR_PeripheralToMemory,
DMA_Mode_Circular,
DMA_MemoryIncMode_Inc,
DMA_Priority_High,
DMA_MemoryDataSize_HalfWord);
/* DMA Channel0 enable */
DMA_Cmd(DMA1_Channel0, ENABLE);
/* Enable DMA1 channel0 Transfer complete interrupt */
DMA_ITConfig(DMA1_Channel0, DMA_ITx_TC, ENABLE);
/* DMA enable */
DMA_GlobalCmd(ENABLE);
}
static void TIM4_Config(void)
{
/* TIM4 configuration:
- TIM4CLK is set to 16 MHz, the TIM4 Prescaler is equal to 128 so the TIM1 counter
clock used is 16 MHz / 128 = 125 000 Hz
- With 125 000 Hz we can generate time base:
max time base is 2.048 ms if TIM4_PERIOD = 255 --> (255 + 1) / 125000 = 2.048 ms
min time base is 0.016 ms if TIM4_PERIOD = 1 --> ( 1 + 1) / 125000 = 0.016 ms
- In this example we need to generate a time base equal to 1 ms
so TIM4_PERIOD = (0.001 * 125000 - 1) = 124 */
/* Time base configuration */
TIM4_TimeBaseInit(TIM4_Prescaler_128, TIM4_PERIOD);
/* Clear TIM4 update flag */
TIM4_ClearFlag(TIM4_FLAG_Update);
/* Enable update interrupt */
TIM4_ITConfig(TIM4_IT_Update, ENABLE);
/* enable interrupts */
enableInterrupts();
/* Enable TIM4 */
TIM4_Cmd(ENABLE);
}
MAIN()
{
/* ADC configuration -------------------------------------------*/
ADC_Config();
/* DMA configuration -------------------------------------------*/
DMA_Config();
/* Enable ADC1 DMA requests*/
ADC_DMACmd(ADC1, ENABLE);
/* Start ADC1 Conversion using TIM1 TRGO*/
ADC_ExternalTrigConfig(ADC1, ADC_ExtEventSelection_Trigger2,
ADC_ExtTRGSensitivity_Rising);
/* Master Mode selection: Update event */
TIM1_SelectOutputTrigger(TIM1_TRGOSource_Update);
/* TIM4 configuration -------------------------------------------*/
TIM4_Config(); //tim4
/* Enable TIM1 */
TIM1_Cmd(ENABLE);
/* Enable Interrupts */
enableInterrupts();
while(1)
{
//ADCData = ADC_GetConversionValue(ADC1);
/* Display BNC voltage values on LCD*/
ShowVoltages(((uint32_t)(ADCData)), BNCVoltage);
}
Thanks for the help. Please let me know how to configure ADC for 1 seconds. I am new in this programming.
Gopal