diff --git a/firmware/code/run.c b/firmware/code/run.c index 8008021..3aa7880 100644 --- a/firmware/code/run.c +++ b/firmware/code/run.c @@ -54,7 +54,7 @@ bqf_mem_t bqf_filters_mem_right[FILTER_STAGES]; static struct { uint32_t freq; int16_t volume; - int16_t vol_mul; + int16_t target_volume; bool mute; } audio_state = { .freq = 48000, @@ -92,7 +92,6 @@ static void _as_audio_packet(struct usb_endpoint *ep) { struct usb_buffer *usb_buffer = usb_current_out_packet_buffer(ep); int16_t *in = (int16_t *) usb_buffer->data; int32_t *out = (int32_t *) userbuf; - uint16_t vol_mul = audio_state.vol_mul; int samples = usb_buffer->data_len / 2; for (int i = 0; i < samples; i++) @@ -116,10 +115,6 @@ static void _as_audio_packet(struct usb_endpoint *ep) { // Block until core 1 has finished transforming the data uint32_t ready = multicore_fifo_pop_blocking(); - // Multiply the outgoing signal with the volume multiple - for (int i = 0; i < samples; i++) - out[i] = out[i] * (int32_t) vol_mul; - i2s_stream_write(&i2s_write_obj, userbuf, samples * 4); // keep on truckin' @@ -154,12 +149,32 @@ void core1_entry() { // Signal to core 0 that the data has all been transformed multicore_fifo_push_blocking(CORE1_READY); + + // Update the volume if required. We do this from core1 as + // core0 is more heavily loaded, doing this from core0 can + // lead to audio crackling. + if (audio_state.volume != audio_state.target_volume) { + // Volume attenuation: + // 0: 0db (default) + // 55: -100db + // 56..: Mute + uint8_t value = 255 + (audio_state.target_volume / 128); + + uint8_t buf[3]; + buf[0] = 65; // register addr + buf[1] = value; // data left + buf[2] = value; // data right + i2c_write_blocking(i2c0, PCM_I2C_ADDR, buf, 3, false); + + audio_state.volume = audio_state.target_volume; + } } } void setup() { set_sys_clock_khz(SYSTEM_FREQ / 1000, true); sleep_ms(100); + // stdio_init_all(); userbuf = malloc(sizeof(uint8_t) * RINGBUF_LEN_IN_BYTES); @@ -185,7 +200,10 @@ void setup() { gpio_set_dir(PCM3060_RST_PIN, GPIO_OUT); gpio_put(PCM3060_RST_PIN, true); - i2c_init(i2c0, 50000); + // The PCM3060 supports standard mode (100kbps) or fast mode (400kbps) + // we run in fast mode so we dont block the core for too long while + // updating the volume. + i2c_init(i2c0, 400000); gpio_set_function(PCM3060_SDA_PIN, GPIO_FUNC_I2C); gpio_set_function(PCM3060_SCL_PIN, GPIO_FUNC_I2C); gpio_pull_up(PCM3060_SDA_PIN); @@ -203,6 +221,11 @@ void setup() { // Don't remove this. Don't do it. sleep_ms(200); + // Set data format to 16 bit right justified, MSB first + buf[0] = 67; // register addr + buf[1] = 0x03; // data + i2c_write_blocking(i2c0, PCM_I2C_ADDR, buf, 2, false); + // Enable DAC buf[0] = 64; // register addr buf[1] = 0xE0; // data @@ -512,22 +535,6 @@ static bool do_get_current(struct usb_setup_packet *setup) { return false; } -// todo this seemed like aood guess, but is not correct -uint16_t db_to_vol[91] = { - 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0001, 0x0002, 0x0002, - 0x0002, 0x0002, 0x0003, 0x0003, 0x0004, 0x0004, 0x0005, 0x0005, - 0x0006, 0x0007, 0x0008, 0x0009, 0x000a, 0x000b, 0x000d, 0x000e, - 0x0010, 0x0012, 0x0014, 0x0017, 0x001a, 0x001d, 0x0020, 0x0024, - 0x0029, 0x002e, 0x0033, 0x003a, 0x0041, 0x0049, 0x0052, 0x005c, - 0x0067, 0x0074, 0x0082, 0x0092, 0x00a4, 0x00b8, 0x00ce, 0x00e7, - 0x0104, 0x0124, 0x0147, 0x016f, 0x019c, 0x01ce, 0x0207, 0x0246, - 0x028d, 0x02dd, 0x0337, 0x039b, 0x040c, 0x048a, 0x0518, 0x05b7, - 0x066a, 0x0732, 0x0813, 0x090f, 0x0a2a, 0x0b68, 0x0ccc, 0x0e5c, - 0x101d, 0x1214, 0x1449, 0x16c3, 0x198a, 0x1ca7, 0x2026, 0x2413, - 0x287a, 0x2d6a, 0x32f5, 0x392c, 0x4026, 0x47fa, 0x50c3, 0x5a9d, - 0x65ac, 0x7214, 0x7fff -}; - static bool do_get_minimum(struct usb_setup_packet *setup) { if ((setup->bmRequestType & USB_REQ_TYPE_RECIPIENT_MASK) == USB_REQ_TYPE_RECIPIENT_INTERFACE) { switch (setup->wValue >> 8u) { @@ -584,14 +591,19 @@ static void _audio_reconfigure() { } static void audio_set_volume(int16_t volume) { - audio_state.volume = volume; - // todo interpolate - volume += CENTER_VOLUME_INDEX * 256; - if (volume < 0) - volume = 0; - if (volume >= count_of(db_to_vol) * 256) - volume = count_of(db_to_vol) * 256 - 1; - audio_state.vol_mul = db_to_vol[((uint16_t)volume) >> 8u]; + // volume is in the range 127.9961dB (0x7FFF) .. -127.9961dB (0x8001). 0x8000 = mute + // the old code reported a min..max volume of -90.9961dB (0xA500) .. 0dB (0x0) + + if (volume == 0x8000) { + // Mute case + } + else if (volume > (int16_t) MAX_VOLUME) { + volume = MAX_VOLUME; + } + else if (volume < (int16_t) MIN_VOLUME) { + volume = MIN_VOLUME; + } + audio_state.target_volume = volume; } static void audio_cmd_packet(struct usb_endpoint *ep) { @@ -603,6 +615,10 @@ static void audio_cmd_packet(struct usb_endpoint *ep) { switch (audio_control_cmd_t.cs) { case 1: { // mute audio_state.mute = buffer->data[0]; + uint8_t buf[2]; + buf[0] = 68; // register addr + buf[1] = buffer->data[0] ? 0x3 : 0x0; // data + i2c_write_blocking(i2c0, PCM_I2C_ADDR, buf, 2, false); break; } case 2: { // volume diff --git a/firmware/code/run.h b/firmware/code/run.h index bbf964c..f683507 100644 --- a/firmware/code/run.h +++ b/firmware/code/run.h @@ -40,10 +40,10 @@ #define ENCODE_DB(x) ((uint16_t)(int16_t)((x)*256)) -#define MIN_VOLUME ENCODE_DB(-CENTER_VOLUME_INDEX) +#define MIN_VOLUME ENCODE_DB(-100) #define DEFAULT_VOLUME ENCODE_DB(0) -#define MAX_VOLUME ENCODE_DB(count_of(db_to_vol)-CENTER_VOLUME_INDEX) -#define VOLUME_RESOLUTION ENCODE_DB(1) +#define MAX_VOLUME ENCODE_DB(0) +#define VOLUME_RESOLUTION ENCODE_DB(0.5f) typedef struct _audio_device_config { struct usb_configuration_descriptor descriptor;