stm32 dma request synchronization settings
Hi,
I have an external SPI 8 channel ADC which is connected to the STM32,one of timers would generate a 32KHz 50% pwm signal which is connected to the ADC convert pin, the ADC has a busy pin which is connected to the EXTI0 of the MCU.
The plan is to use the EXTI0 to trigger 8 16bit SPI reads from the ADC, so after gathering 640 samples I would get an interrupt, to process the incoming data, since Interrupting the CPU 32000 times per second would not allow any other meaning full job to be done,
So I have done like this
Pin A0 configured as EXTI0
SPI DMA settings
SPI NVIC settings
my code is like this
uint8_t SPISend = 1;
void HAL_SPI_TxRxCpltCallback(SPI_HandleTypeDef *hspi){
if (hspi->Instance == SPI2) {
SPISend = 1;
}
}
int main(void){
uint8_t tx[5120]={0,0,1,0x11,0x22,0x33,0x44,0x55,0x66,0x77,0x88};
uint8_t rx[5120]={0};
//init IO with CubMX
while (1){
if(SPISend == 1){
HAL_SPI_TransmitReceive_DMA(&hspi2,tx,rx,5120);
}
}
}
This code works only when I enable the EXTI interrupt, which would ruin the hole prepose of eliminating the use of interrupts,
Is there any work around this so I would reduce the CPU overhead and interrupts, so the CPU could do other time critical tasks.