Hello,
I am using a STM32F429I-Discovery board for a project involving the use of both DAC channels. I am using the Peripheral driver library for faster coding. Despite having configured everything as specified in the docs and the library I cannot get the DAC to work. When using PA5, for instance, it remains still at 0V.
int main(void)
{
GPIO_Config(); // configure all the pins used for this module
DAC_Configuration();
while(1) {
DAC_SetChannel2Data(DAC_Align_12b_R, (uint32_t)868);
}
}
void GPIO_Config(void)
{
GPIO_InitTypeDef GPIO_InitStruct;
RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOA, ENABLE);
// Output CCP signal
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_6;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AF;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOB, &GPIO_InitStruct);
// PB6 is used as an alternate function. It is used to output a PWM generated by Timer 4
// This pin generates the output SCP signal.
GPIO_PinAFConfig(GPIOB, GPIO_PinSource6, GPIO_AF_TIM4);
// Output PMS signal
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_12;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOD, &GPIO_InitStruct);
// Input CP signal
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_0;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_IN;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOB, &GPIO_InitStruct);
// Input PMS signal
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_1;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_IN;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOC, &GPIO_InitStruct);
// Output Inj
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_4;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_OUT;
GPIO_InitStruct.GPIO_Speed = GPIO_Speed_100MHz;
GPIO_InitStruct.GPIO_OType = GPIO_OType_PP;
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOC, &GPIO_InitStruct);
// DAC outputs to simulate analog signals
GPIO_InitStruct.GPIO_Pin = GPIO_Pin_5;
GPIO_InitStruct.GPIO_Mode = GPIO_Mode_AN;
GPIO_InitStruct.GPIO_PuPd = GPIO_PuPd_NOPULL;
GPIO_Init(GPIOA, &GPIO_InitStruct);
}
// Phase 2
void DAC_Configuration(void) {
DAC_InitTypeDef DAC_InitStructure;
/* Enable DAC clock */
RCC_APB1PeriphClockCmd(RCC_APB1Periph_DAC, ENABLE);
/* Configure DAC channel 1, 2 */
DAC_InitStructure.DAC_Trigger = DAC_Trigger_None;
DAC_InitStructure.DAC_WaveGeneration = DAC_WaveGeneration_None;
DAC_InitStructure.DAC_OutputBuffer = DAC_OutputBuffer_Enable;
DAC_Init(DAC_Channel_2, &DAC_InitStructure);
/* Enable DAC channel 1, 2 */
DAC_Cmd(DAC_Channel_2, ENABLE);
}
I have omitted most of the code, such as Timer configuration, NVIC, etc. It is not related to the DAC so it should not be affecting it. The debugger shows that all the lines of the code are being reached. I have tried disabling the output buffer as well, without success. The oscillator has been configured, as well as AHB1, APB1 and APB2 clocks. Is there something I am missing? I am measuring the output in PA5 with an oscilloscope (Picoscope 2000 series).
