sfera-labs / arduino-pico-i2s-audio Goto Github PK

Will you be adding a readme to the code page, and ideally an example or two, as with other Arduino libraries? I'm not entirely clear how to try this out, without them.

This probably should have been on a Discussion thread, rather than in an issue, but there currently isn't a Discussion page. Maybe worth adding one?

I'm intrigued to see that you can set the three I2S pins separately, as opposed to the standard arduino-pico I2S (16 bit out only), where two of them have to be adjacent, so you only get to set two. Can all three be on any GPIO pin, in this version? Does that place any limitations on the use of PIO functions on other pins, e.g. adjacent ones?

Hello,
I bought a WM8782 module on audiophonics.
I would like to use it to make an USB dual guitar recorder thanks to the rp pico, but I don't realy understand how to use the i2s lib with the master clock. Is it possible to do ? do you have some advice ?

Hi,
I'm also working on the I2S of RP2040. But I can not find suitable Arduino library until find yours. Do you have any plan to add TX for full duplex? And if possible, I advise to use interrupt to detect the data transformation with callback register api for upper layer. Thanks.

This one's a doozy.
I use your (great!) machine_i2s.c with the C-SDK like this:

#include "pico/stdlib.h"
#include "machine_i2s.c"

#define SCK 3
#define WS 4 // needs to be SCK +1
#define SD 29
#define BPS 32 // 24 is not valid in this implementation, but INMP441 outputs 24 bits samples
#define RATE 16000

int main() {
	stdio_init_all();
	machine_i2s_obj_t* i2s0 = machine_i2s_make_new(0, SCK, WS, SD, RX, BPS, STEREO, /*ringbuf_len*/SIZEOF_DMA_BUFFER_IN_BYTES, RATE);
	int32_t buffer[I2S_RX_FRAME_SIZE_IN_BYTES /4];
	while (true) {
		machine_i2s_stream_read(i2s0, (void*)&buffer[0], I2S_RX_FRAME_SIZE_IN_BYTES);
		printf("%.6x %.6x\n", buffer[0], buffer[1]);			
	}
}

but I don't get any samples out without the most peculiar change:
if I add on https://github.com/sfera-labs/arduino-pico-i2s-audio/blob/master/src/machine_i2s.c#L232 the following:

printf("%d %d\n", rbuf->head,rbuf->tail);

it suddenly starts spewing out correct frames! So it seems to me that the printf statement somehow materializes the head and tail values, but my knowledge of the pico and or C is not nearly enough to start to understand this.