added i2s Device Tree Files and i2s streaming test (esp32->python)

i2s_streaming_test/rk3568-i2s3-m0-inmp441.dts

@@ -0,0 +1,53 @@
+/dts-v1/;
+/plugin/;
+
+ / {
+    metadata {
+        title = "Enable I2S3-M0 INMP441";
+        compatible = "radxa,rock-3c", "radxa,zero3";
+        category = "audio";
+        description = "Enable INMP441 on I2S3-M0";
+        /* Hard-coded GPIO numbers for GPIO3_A3/A4/A5/A6 */
+        exclusive = "99", "100", "102", "101", "i2s3_2ch";
+    };
+};
+
+&{/} {
+    dummy_codec: dummy-codec {
+        compatible = "rockchip,dummy-codec";
+        #sound-dai-cells = <0>;
+    };
+
+    dummy_sound: dummy-sound {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        compatible = "simple-audio-card";
+        simple-audio-card,format = "i2s";
+        simple-audio-card,bitclock-master = <&i2s3_2ch>;
+        simple-audio-card,frame-master = <&i2s3_2ch>;
+        simple-audio-card,mclk-fs = <256>;
+        simple-audio-card,name = "i2s3-inmp441";
+        simple-audio-card,dai-link@0 {
+            reg = <0>;
+            format = "i2s";
+            cpu {
+                sound-dai = <&i2s3_2ch>;
+            };
+            codec {
+                sound-dai = <&dummy_codec>;
+            };
+        };
+    };
+};
+
+&i2s3_2ch {
+    pinctrl-0 = <&i2s3m0_sclk
+                 &i2s3m0_lrck
+                 &i2s3m0_sdi
+                 &i2s3m0_sdo>;
+    status = "okay";
+};
+
+&i2c3 {
+    status = "disabled";
+};

i2s_streaming_test/rk3568-i2s3-m0-inmp441_dummy.dts

@@ -0,0 +1,51 @@
+/dts-v1/;
+/plugin/;
+
+ / {
+    metadata {
+        title = "Enable I2S3-M0 INMP441";
+        compatible = "radxa,rock-3c", "radxa,zero3";
+        category = "audio";
+        description = "Enable INMP441 on I2S3-M0";
+        /* Hard-coded GPIO numbers for GPIO3_A3/A4/A5/A6 */
+        exclusive = "99", "100", "102", "101", "i2s3_2ch";
+    };
+};
+
+&{/} {
+    dummy_codec: dummy-codec {
+        compatible = "rockchip,dummy-codec";
+        #sound-dai-cells = <0>;
+    };
+
+    dummy_sound: dummy-sound {
+        #address-cells = <1>;
+        #size-cells = <0>;
+        compatible = "simple-audio-card";
+        simple-audio-card,format = "i2s";
+        simple-audio-card,mclk-fs = <256>;
+        simple-audio-card,name = "i2s3-inmp441";
+        simple-audio-card,dai-link@0 {
+            reg = <0>;
+            format = "i2s";
+            cpu {
+                sound-dai = <&i2s3_2ch>;
+            };
+            codec {
+                sound-dai = <&dummy_codec>;
+            };
+        };
+    };
+};
+
+&i2s3_2ch {
+    pinctrl-0 = <&i2s3m0_sclk
+                 &i2s3m0_lrck
+                 &i2s3m0_sdi
+                 &i2s3m0_sdo>;
+    status = "okay";
+};
+
+&i2c3 {
+    status = "disabled";
+};

i2s_streaming_test/serial_sound.py

@@ -0,0 +1,46 @@
+import serial
+import wave
+import struct
+
+# === CONFIGURATION ===
+SERIAL_PORT = 'COM7'         # Update this to match your system
+BAUD_RATE = 1000000
+SAMPLE_RATE = 8000
+DURATION_SECONDS = 5
+OUTPUT_FILE = 'esp32_audio.wav'
+
+# === SETUP SERIAL ===
+ser = serial.Serial(SERIAL_PORT, BAUD_RATE, timeout=0.01)
+
+# === PREPARE TO CAPTURE ===
+print(f"Recording {DURATION_SECONDS} seconds of audio...")
+
+samples = []
+max_samples = SAMPLE_RATE * DURATION_SECONDS
+chunk_size = 4096  # bytes
+
+# === CAPTURE LOOP ===
+while len(samples) < max_samples:
+    data = ser.read(chunk_size)
+    for i in range(0, len(data) - 1, 2):
+        sample = int.from_bytes(data[i:i+2], byteorder='little', signed=True)
+        samples.append(sample)
+    if len(samples) % 1000 == 0:
+        print(f"{len(samples)} samples captured")
+
+ser.close()
+
+# === NORMALIZE AUDIO ===
+peak = max(abs(s) for s in samples)
+scale = 32767 / peak if peak > 0 else 1.0
+normalized = [int(max(-32768, min(32767, s * scale))) for s in samples]
+
+# === WRITE TO WAV FILE ===
+with wave.open(OUTPUT_FILE, 'w') as wav:
+    wav.setnchannels(1)
+    wav.setsampwidth(2)  # 16-bit
+    wav.setframerate(SAMPLE_RATE)
+    for sample in normalized:
+        wav.writeframes(struct.pack('<h', sample))
+
+print(f"Saved normalized audio to {OUTPUT_FILE}")

i2s_streaming_test/stream_i2s.ino

@@ -0,0 +1,51 @@
+#include <driver/i2s.h>
+
+#define I2S_WS      6   // LRCL (Word Select)
+#define I2S_SCK     7   // BCLK (Serial Clock)
+#define I2S_SD      8   // DOUT (Serial Data from mic)
+
+#define I2S_PORT    I2S_NUM_0
+#define BUFFER_SIZE 2048  // Larger buffer = fewer calls
+
+void setup() {
+  Serial.begin(1000000);  // High-speed serial for streaming audio
+
+  // I2S configuration
+  const i2s_config_t i2s_config = {
+    .mode = i2s_mode_t(I2S_MODE_MASTER | I2S_MODE_RX),
+    .sample_rate = 8000,
+    .bits_per_sample = I2S_BITS_PER_SAMPLE_32BIT,
+    .channel_format = I2S_CHANNEL_FMT_ONLY_LEFT,
+    .communication_format = I2S_COMM_FORMAT_I2S,
+    .intr_alloc_flags = ESP_INTR_FLAG_LEVEL1,
+    .dma_buf_count = 4,
+    .dma_buf_len = BUFFER_SIZE / 4,
+    .use_apll = false,
+    .tx_desc_auto_clear = false,
+    .fixed_mclk = 0
+  };
+
+  const i2s_pin_config_t pin_config = {
+    .bck_io_num = I2S_SCK,
+    .ws_io_num = I2S_WS,
+    .data_out_num = I2S_PIN_NO_CHANGE,
+    .data_in_num = I2S_SD
+  };
+
+  i2s_driver_install(I2S_PORT, &i2s_config, 0, NULL);
+  i2s_set_pin(I2S_PORT, &pin_config);
+}
+
+void loop() {
+  uint8_t buffer[BUFFER_SIZE];
+  size_t bytes_read;
+
+  if (i2s_read(I2S_PORT, &buffer, BUFFER_SIZE, &bytes_read, portMAX_DELAY) == ESP_OK && bytes_read > 0) {
+    for (int i = 0; i < bytes_read; i += 4) {
+      int32_t sample_32 = *(int32_t*)&buffer[i];
+      int16_t sample_16 = sample_32 >> 12;  // Less aggressive shift
+
+      Serial.write((uint8_t*)&sample_16, 2);
+    }
+  }
+}