using circular buffer for audio samples

[benbiles]

hi, I'm trying to use your circular buffer to buffer audio samples before sending them on over an RF module with an arduino due and an audio codec. There is actually a 64byte fifo buffer on the RF IC but I'd like to learn how to use circular buffers all the same !

I am finding it difficult to understand where or how i should copy in the samples to the curcular buffer. I would be greatful if you could point me in the right direction. hopfuly i'm not totally off track !! i removed all the RF and audio Codec code to try and make my problem clearer.. the samples come in at one sample at a time, so i'm not sure about your dump to UART example using a for loop.. should I send the cucular array one byte at a time and the array decides where the next free slot in the array is ?

Also where would I read data from ? how do I point to the least oldest byte in the array so I can send that over my RF module..

`// arduino circular buffer, digital audio TX

define BUFFER_SIZE 16

enum BufferStatus {BUFFER_OK, BUFFER_EMPTY, BUFFER_FULL};

enum BufferStatus status; uint8_t byte_from_buffer;

uint8_t tempy;
enum BufferStatus status_tx;

uint8_t newAudioSamples[16]; // samples come in one at a time , but I could make a normal array of 16 bytes at a time ?

struct Buffer { uint8_t data[BUFFER_SIZE]; uint8_t newest_index; uint8_t oldest_index;};

// checks for writing data into the circular buffer ? enum BufferStatus bufferWrite(uint8_t byte){ uint8_t next_index = (buffer.newest_index+1) % BUFFER_SIZE;

if (next_index == buffer.oldest_index){ return BUFFER_FULL; } buffer.data[buffer.newest_index] = byte; buffer.newest_index = next_index; return BUFFER_OK; }

// checks for reading data from the circular buffer ? enum BufferStatus bufferRead(uint8_t *byte){ if (buffer.newest_index == buffer.oldest_index){ return BUFFER_EMPTY; } *byte = buffer.data[buffer.oldest_index]; buffer.oldest_index = (buffer.oldest_index+1) % BUFFER_SIZE; return BUFFER_OK; }

void setup() { // initialise_audio_codec(); // initialise_RFmodule(); }

void loop() {

rxDATA(); // recieve samples into circular buffer txDATA(); // send samples form circular buffer to RF module

}

// RECIEVE DATA INTO BUFFER IF ROOM void rxDATA {

status_tx = bufferRead(&tx_buffer, &tempy);      
if (status_tx == BUFFER_EMPTY){  
  return 0;   
  }
 else { 
     for (uint8_t i=0; i<BUFFER_SIZE; i++){
     &buffer.data(i) = newAudioSamples(i); /// ????? // should i specify an array position for samples, would'nt it be differnt? ?? how do i write into circular buffer? 
}}

}

// SEND DATA

void txDATA { status = bufferRead(&byte_from_buffer); if (status == BUFFER_OK) { /* we have data */ for (uint8_t i=0; i<BUFFER_SIZE; i++){ RH_RF24.send (&buffer.data(i) // dump TX data over RF module ??? do i need to specify an array position ?? }} else { return; } } `