I have ADC & DMA working well, scanning 2 channels in circular mode using full and half full callback routines. It works swimmingly. I also have SPI transmissions happening off of a timer interrupt. The problem is the SPI transmissions are being disrupted by the ADC operation. I need the DAC timing to be solid, but is it jittery. If I disable the ADC by kiling the call to start the ADC-DMA cycle the SPI looks perfect, so I know its the ADC that is causing it. Is there a way to set priorities so the SPI dominates over the ADC system?