Hey Guys,
I'm struggling to figure out how to stream sine waves at a constant frequency for 8 channels. Each channel has its own sine wave frequency. The issue I'm having is how to stream all these at the same time. I created an array for each sine wave frequency. I thought to use DMA, but the issue is that I have to combine two sine waves into one array with different length of samples. So is there a way for the DMA to interleave two arrays of different lengths into one I2S module?
I can't seem to find an answer for this.
I'm happy with just using interrupts (if fast enough) if the DMA will not work. For interrupt function :HAL_I2S_Transmit_IT(), would I be able to use the Tx FIFO from this function to send 2, 16 bit data at once. (left and right sample) for each DAC
while(1)
{
HAL_I2S_Transmit_IT(&hi2s1, &NorthSpeakerSamples[NS_S], 1); // these two functions would have to be combined to work properly.
HAL_I2S_Transmit_IT(&hi2s1, &SouthSpeakerSamples[SS_S], 1);
HAL_I2S_Transmit_IT(&hi2s2, &EastSpeakerSamples[NS_S], 1);// these two functions would have to be combined to work properly.
HAL_I2S_Transmit_IT(&hi2s2, &WestSpeakerSamples[SS_S], 1);
HAL_I2S_Transmit_IT(&hi2s3, &NorthCoilSamples[NS_S], 1);// these two functions would have to be combined to work properly.
HAL_I2S_Transmit_IT(&hi2s3, &SouthCoilSamples[SS_S], 1);
HAL_I2S_Transmit_IT(&hi2s6, &NorthCoilSamples[NS_S], 1);// these two functions would have to be combined to work properly.
HAL_I2S_Transmit_IT(&hi2s6, &SouthCoilSamples[SS_S], 1);
}void HAL_I2S_TxCpltCallback(I2S_HandleTypeDef *hi2s)
{
//NS_S, SS_S, ES_S, WS_S ; // NorthSpeaker_Sample, South..etc...
// NC_S, SC_S, EC_S, WC_S ; // NorthCoil_Sample, South..etc...
// NS_Snum, SS_Snum, ES_Snum, WS_Snum ; // NorthSpeaker_SampleNumberOfSamples, South..etc...
// NC_Snum, SC_Snum, EC_Snum, WC_Snum ; // NorthCoil_SampleSampleNumberOfSamples, South..etc...
if(hi2s==hi2s1)
{
if (NS_S<NS_Snum) ++NS_S; else NS_S=0;
if (SS_S<SS_Snum) ++SS_S; else SS_S=0;
}
}