Sipeed MAix Bit with MIC Maixduino(Arduino) で マイクのお試し

1. Sipeed MAix Bit 側の Arduino プログラムです。

1) I2S でPC へ送るデータは、
  Sampling Rate: 16000
  Monoral   16bit

2) Serial1
   Baud Rate : 921600 * 1.6

3) i2s_receive_data_dma(I2S_DEVICE_0, rx_buf, FRAME_LEN * 2, DMAC_CHANNEL0);
で上がって来るデータは、32bit Stereo の様なので、
片側のチャネルの 16bit のみを、PC に転送します。

/* * i2s_k210_arduino_1 * main.cpp * https://www.arduino.cc/en/Reference/I2S * https://github.com/kendryte/kendryte-doc-standalone-programming-guide/blob/master/en/I2S.md * https://github.com/kendryte/kendryte-standalone-demo/blob/develop/i2s_dma/main.c */ #include <Arduino.h> #include <I2S.h> // I2S SAMPLE_RATE #define SAMPLE_RATE 16000 //#define SAMPLE_RATE 38640 // I2S CHUNK size //#define FRAME_LEN 256 // CHUNK = 256(Monoral) / 512(Stereo) #define FRAME_LEN 512 // CHUNK = 512(Monoral) / 1024(Stereo) // Serial1 BAUD_RATE //#define BAUD_RATE 115200 //#define BAUD_RATE 921600 #define BAUD_RATE 1474560 // 921600 * 1.6 Max Speed //#define BAUD_RATE 921600*2 //uint32_t rx_buf[1024]; uint32_t rx_buf[FRAME_LEN*2]; // Stereo int32_t lp; // 0 - not ready / 1 - ready / 2 - resend char ready_f; /* * Seral1 I2S Sound data + '\r\n' Record */ typedef struct { //uint8_t dt[FRAME_LEN*2*2]; uint8_t dt[FRAME_LEN*2]; uint8_t crlf[2]; } SER_BLOCK_DT; SER_BLOCK_DT ser_block_dt; void io_mux_init(){ // MAIXPY code sample //fm.register(20,fm.fpioa.I2S0_IN_D0) //fm.register(19,fm.fpioa.I2S0_WS) //fm.register(18,fm.fpioa.I2S0_SCLK) fpioa_set_function(20, FUNC_I2S0_IN_D0); fpioa_set_function(19, FUNC_I2S0_WS); fpioa_set_function(18, FUNC_I2S0_SCLK); } void check_ready(){ uint8_t rd; size_t lng; //Serial.printf("ready_f2=%d\r\n",ready_f); while(1){ if (ready_f != 0) break; lng=Serial1.readBytes((uint8_t *)&rd,1); if (lng ==1 && rd == 's') ready_f = 1; else if(lng ==1 && rd == 'r') ready_f = 2; } //Serial.printf("ready_f3=%d\r\n",ready_f); } /* * write_dtx_blk(uint32_t *dt,size_t buf_len) * Serial1 block write * Stereo 32bit -> Monoral 16bit */ void write_dtx_blk(uint32_t *dt,size_t buf_len){ //Serial.printf("ready_f=%d\r\n",ready_f); int j=0; // I2S 32bit stereo data and 1 channel active -> 16bit monoral data for (size_t i = 0; i < buf_len;i+=2){ uint32_t k = dt[i]; //uint8_t d0,d1,d2,d3; //d0 = (uint8_t)(k >> 24 & 0x000000ff); //d1 = (uint8_t)(k >> 16 & 0x000000ff); //d2 = (uint8_t)(k >> 8 & 0x000000ff); //d3 = (uint8_t)(k & 0x000000ff); ser_block_dt.dt[j*2]=(uint8_t)(k >> 8 & 0x000000ff); ser_block_dt.dt[j*2+1]=(uint8_t)(k & 0x000000ff); j++; } while(1){ if (ready_f != 1) check_ready(); // 1ブロックで送ってみます。 Serial1.write((uint8_t *)&ser_block_dt,sizeof(ser_block_dt)); ready_f=0; check_ready(); if (ready_f == 1) break; else ready_f=1; } } /* * write_dtx(uint32_t *dt,size_t buf_len) * 1 バイト毎送ります。 * Stereo 32bit -> Monoral 16bit */ void write_dtx(uint32_t *dt,size_t buf_len){ //Serial.printf("ready_f=%d\r\n",ready_f); while(1){ if (ready_f != 1) check_ready(); // 1個1個送った方が、データ抜けが無いかもしれない。 for(int i=0;i<buf_len;i+=2){ uint32_t k = dt[i]; //unsigned char d0,d1; unsigned char d2,d3; //d0 = (unsigned char)(k >> 24 & 0x000000ff); //d1 = (unsigned char)(k >> 16 & 0x000000ff); d2 = (unsigned char)(k >> 8 & 0x000000ff); d3 = (unsigned char)(k & 0x000000ff); //Serial1.printf("%02x",d0); //Serial1.printf("%02x",d1); //Serial1.printf("%02x",d2); //Serial1.printf("%02x",d3); //Serial1.print(","); Serial1.write(d2); Serial1.write(d3); } Serial1.print("\r\n"); ready_f=0; check_ready(); if (ready_f == 1) break; else ready_f=1; } } /* * write_dtx_dump(uint32_t *dt,size_t buf_len) * デバッグ用のダンプを送ります。 */ void write_dtx_dump(uint32_t *dt,size_t buf_len){ //Serial.printf("ready_f=%d\r\n",ready_f); while(1){ if (ready_f != 1) check_ready(); // 1個1個送った方が、データ抜けが無いかもしれない。 for(int i=0;i<buf_len;i++){ uint32_t k = dt[i]; unsigned char d0,d1; unsigned char d2,d3; d0 = (unsigned char)(k >> 24 & 0x000000ff); d1 = (unsigned char)(k >> 16 & 0x000000ff); d2 = (unsigned char)(k >> 8 & 0x000000ff); d3 = (unsigned char)(k & 0x000000ff); Serial1.printf("%02x",d0); Serial1.printf("%02x",d1); Serial1.printf("%02x",d2); Serial1.printf("%02x",d3); Serial1.print(","); } Serial1.print("\r\n"); ready_f=0; check_ready(); if (ready_f == 1) break; else ready_f=1; } } void setup() { // code from https://github.com/kendryte/kendryte-standalone-demo/blob/develop/i2s_dma/main.c //sysctl_pll_set_freq(SYSCTL_PLL0, 320000000UL); //sysctl_pll_set_freq(SYSCTL_PLL1, 160000000UL); //sysctl_pll_set_freq(SYSCTL_PLL2, 45158400UL); lp=0; ready_f=0; ser_block_dt.crlf[0]=0x0d; ser_block_dt.crlf[1]=0x0a; // put your setup code here, to run once: Serial.begin(115200); //Serial1.begin(115200,rx,tx); //Serial1.begin(9600, 17, 15); //Serial1.begin(115200, 17, 15); Serial1.begin(BAUD_RATE, 17, 15); while (!Serial) { ; // wait for serial port to connect. Needed for native USB port only } Serial.println("Start i2s_k210_arduino_1"); while (!Serial1) { ; // wait for serial port to connect. Needed for native USB port only } Serial.println("Start Serial1"); io_mux_init(); // wait for 's' from Serial1 check_ready(); // MAIXPY code sample //i2s_init(i2s_device_number_t device_num, i2s_transmit_t rxtx_mode, uint32_t channel_mask); //rx = I2S(I2S.DEVICE_0) //rx.channel_config(rx.CHANNEL_0, rx.RECEIVER, align_mode = I2S.STANDARD_MODE) i2s_init(I2S_DEVICE_0, I2S_RECEIVER, 0x3); Serial.println("I2S init OK"); // align_mode -> STANDARD_MODE / LEFT_JUSTIFYING_MODE / RIGHT_JUSTIFYING_MODE i2s_rx_channel_config(I2S_DEVICE_0, I2S_CHANNEL_0, RESOLUTION_16_BIT, SCLK_CYCLES_32, TRIGGER_LEVEL_4, LEFT_JUSTIFYING_MODE); uint32_t sample_rate_act; //uint32_t i2s_set_sample_rate(i2s_device_number_t device_num, uint32_t sample_rate); sample_rate_act = i2s_set_sample_rate(I2S_DEVICE_0, SAMPLE_RATE); Serial.printf("sample_rate_act=%d\r\n",sample_rate_act); } void loop() { //void i2s_receive_data_dma(i2s_device_number_t device_num, uint32_t *buf, size_t buf_len, // dmac_channel_number_t channel_num); // I2S's data is stereo data. // Samples point = FRAME_LEN // Comming data size = FRAME_LEN*2 i2s_receive_data_dma(I2S_DEVICE_0, rx_buf, FRAME_LEN * 2, DMAC_CHANNEL0); //lp++; //Serial.printf("lp=%d\r\n",lp); //write_dtx(rx_buf,FRAME_LEN * 2); // Serial1 one byte Transfer write_dtx_blk(rx_buf,FRAME_LEN * 2); // Seilal1 block Tramsfer //write_dtx_dump(rx_buf,20); // For Debug Dump }

2. 念のために、 PC 側の Python Script も掲載して置きます。

# -*- coding: utf-8 -*- ''' k210-mic2b.py K210 の内臓マイクから音を拾って、Serial 通信で、PC側で受信して、 スピーカーに音を出してみます。 ハンドシェイクを行います。 https://teratail.com/questions/127864 https://www.sejuku.net/blog/69511 ''' import pyaudio import serial import binascii import time #CHUNK=1024 #CHUNK=2**11 CHUNK=512 #CHUNK=256 #CHUNK=2048 #CHUNK=2**12 #RATE=8000 RATE=16000 #RATE=38640 #RATE=44100 p=pyaudio.PyAudio() stream=p.open(format = pyaudio.paInt16, channels = 1, rate = RATE, frames_per_buffer = CHUNK, input = False, output = True) #Speed = 115200 #Speed = 460800 #Speed = 921600 #Speed = 921600+128000 Speed = int(921600*1.6) #Speed = int(921600*2) #ser = serial.Serial('COM7',Speed,timeout=None) ser = serial.Serial('COM7',Speed,timeout=10) ser.reset_input_buffer() sync=True t1 = time.time()+1 ct=0 def read_dtx(): fst_f=1 while True: if fst_f==1: ser.write(b's') fst_f=0 else: ser.reset_input_buffer() ser.write(b'r') line = ser.read(CHUNK*2+2) lng = len(line) #print('lng=',lng) if lng == CHUNK*2+2: if line[CHUNK*2:] == b'\r\n' : return line else: print(line[CHUNK*2:]) else: print('lng=',lng) while stream.is_active(): #line = ser.readline().strip() line = read_dtx() output = stream.write(line[:CHUNK*2]) ct+=1 if time.time() >= t1: bt= ct * CHUNK*2 print(bt,'byte/s') ct=0 t1 = time.time()+1 stream.stop_stream() stream.close() p.terminate() print("Stop Streaming")

何とか、PCのスピーカーから聞き取れる程にはなりました。
Bit の マイクは、結構感度が良すぎるみたいで、直ぐピークになります。
ただ、もう少し改善も出来そうです。

次回は、
i2s_handle_data_dma(I2S_DEVICE_0, data, &irq);
を使った、イベントでの取り込みを考えてみます。