STM32F103 Dual ADC with DMA skips channel

[Jeroen3]

Posted on November 03, 2016 at 14:38The original post was too long to process during our migration. Please click on the attachment to read the original post.

[Jeroen3]

Posted on November 03, 2016 at 16:18

Well. What a bit of rubber duck debugging can't fix, heh...

1. The skipped channel was caused since the ADC was written to while  ADC_CR2_CAL was on.Fix:

  /* Power ON */

  ADC1->CR2 = ADC_CR2_ADON | ADC_CR2_CAL;  ADC2->CR2 = ADC_CR2_ADON | ADC_CR2_CAL;  /* Wait 4 ADC cycles, 24 cpu cycles */  timeout = 24;  while(timeout--);  /* Auto Calibrate */  ADC1->CR2 |= ADC_CR2_CAL;  ADC2->CR2 |= ADC_CR2_CAL;  while(ADC1->CR2 & ADC_CR2_CAL);  while(ADC2->CR2 & ADC_CR2_CAL);  // Clear all flags  ADC1->SR = 0;  ADC2->SR = 0;2. After this, an address misalignment occurred using the DMA. This was caused by setting ADC_CR2_DMA before turning on the DMA channel. This causes an inevitable DMA operation (with CAL results) when turning the DMA channel on.So many little things aren't in the manual...

[Tesla DeLorean]

Posted on November 03, 2016 at 16:53

So many little things aren't in the manual...

Somehow I suspect a manual that covered all the minutiae of the implementation would be impenetrable, and it is not as if most people read it now anyway..