comments

gg.c

@@ -30,8 +30,8 @@ uint32_t mmc_position;/* current reading position on mmc */
 uint8_t overflows = 1;/* remaining counter overflows until next sample */
 #define SAMPLE_BITS 11
 
-#define BUFFER_SIZE 92
-#define REFRESH_AMOUNT 64
+#define BUFFER_SIZE 64
+#define REFRESH_AMOUNT 32
 #define REFRESH_SIZE (BUFFER_SIZE - REFRESH_AMOUNT)
 uint8_t buffer[BUFFER_SIZE];/* buffer for mmc data */
 
@@ -69,6 +69,9 @@ int main(void)
 	{
 		if(pos == refresh_buffer)/* refresh buffer if running low */
 		{
+			/* TODO: this won't do. we don't have enough time to read unnecessary bytes -> read data with the same speed as we consume it, keeping a small buffer. */
+			/* expect 2 bit read from mmc between 2 timer interrupts --> 2 byte read per sample played */
+			
 			mmc_read_sector(mmc_position, buffer + (ref + REFRESH_SIZE) % BUFFER_SIZE);//, BUFFER_SIZE - ref), buffer, REFRESH_AMOUNT - (BUFFER_SIZE - ref));
 			/*       pos on sd   , first buffer address                       , 1st buffer size  ,2nd buf, 2nd buffer size                    */
 			refresh_buffer = (refresh_buffer + REFRESH_AMOUNT) % BUFFER_SIZE;