Multi-channel continuous DMA Conversions

In a multi-channel ADC setup with continuous conversions using DMA, you’ll need to determine which ADC channel triggered the DMA callback in order to perform different tasks for each channel. To achieve this, you can follow these steps:

1. Configure ADC Channels: Set up your ADC to scan through multiple channels in continuous mode. Configure the ADC and DMA peripherals according to your microcontroller’s specifications. Each channel should generate an interrupt after a conversion is completed.

2. Configure DMA: Set up the DMA controller to handle the ADC data transfers. Make sure to enable the circular buffer mode so that DMA continues fetching data indefinitely.

3. DMA Callback Function: This function will be called by the DMA controller whenever a DMA transfer is complete. Since you are performing continuous conversions, this callback will be triggered after each complete scan of all the ADC channels.

4. Channel Identification: To identify which channel has triggered the callback, you can use a few methods:

a. Use ADC’s Current Channel Register: Many microcontrollers have a register that stores the current active channel. In the DMA callback, you can read this register to determine the current channel. Then, you can use conditional statements to perform different tasks based on the active channel.

b. Use DMA Transfer Counter: DMA controllers often have a transfer counter that indicates how many transfers have been completed. Since you’re performing a scan of multiple channels, you can calculate the active channel based on the transfer count and the total number of channels.

5. Conditional Statements: Once you’ve identified the active channel, you can use conditional statements to execute specific tasks based on the channel. For example:

void DMA_ADC_Callback(void) {
// Identify the active channel using the methods described above
uint8_t activeChannel = …; // Determine the active channel here

// Perform tasks based on the active channel
if (activeChannel == CHANNEL_0) {
// Task for channel 0
} else if (activeChannel == CHANNEL_1) {
// Task for channel 1
} else if (activeChannel == CHANNEL_2) {
// Task for channel 2
}
// Add more conditions for other channels as needed
}
`

By utilizing the methods mentioned above, you can accurately identify the channel that triggered the DMA callback and execute the appropriate tasks for each channel. Make sure to consult your microcontroller’s documentation for specific register names and details regarding DMA and ADC configuration.