ESP8266 OpenSound Control

Here some example Arduino code for sending and receiving OSC via the cheap ESP8266 serial WiFi module.

Note that the Open Sound Control messages here are very basic - only 4 bytes packed into a single 32bit integer.

• upload the code below to an Arduino.
• connect ESP8266 TX pin to Arduino pin0.
• connect ESP8299 RX to Arduino pin1. It is safest to use a 3V3 lever converter for this line (or at least a voltage divider).
• power the ESP8266 (VCC and GND) from an external 3V source. Do not use the Arduino 3V3 pin as it cannot provide the required current. I used an LF33CV voltage regulator to get 3.3V from the 5V supply that also powers the Arduino.
• connect ESP8288 RESET pin to Arduino pin4.
• and last, connect ESP8266 CH_PD to 3V3

Optional: connect a separate USB-Serial (FTDI) chip to Arduino pins 2 and 3 to use software serial debugging. Start debugging in a terminal with something like screen /dev/tty.usbserial-A4015TKA 115200

The Arduino code sits and waits for an incoming OSC message (/tap). It then replies by sending out a counter-message (/sti).

//f0 150705
//sending and receiving UDP OSC with an ESP8266
//for an Arduino + ESP8266 with firmware 0.9.5.2

#include <SoftwareSerial.h>

#define WLAN_SSID  "SSID"
#define WLAN_PASS  "PASS"
#define WLAN_ADDR  "192.168.1.51" //laptop running sc
#define PORT  1112 //incoming OSC port
String tag = "/tap"; //incoming OSC addy

SoftwareSerial mySerial(2, 3);

uint8_t buf[16];
byte cnt;
byte id, on, hi, lo;
boolean resp;

void setup() {

  //--OSC message
  buf[0] = 47;   // /
  buf[1] = 115;  // s
  buf[2] = 116;  // t
  buf[3] = 105;  // i
  buf[4] = 0;
  buf[5] = 0;
  buf[6] = 0;
  buf[7] = 0;
  buf[8] = 44;   // ,
  buf[9] = 105;  // i
  buf[10] = 0;
  buf[11] = 0;
  buf[12] = 4;   // a high   (id)
  buf[13] = 3;   // a low    (on)
  buf[14] = 2;   // b high   (hi)
  buf[15] = 0;   // b low    (lo)

  mySerial.begin(115200);
  Serial.begin(115200);
  Serial.setTimeout(10000);
  mySerial.println("");
  mySerial.println("starting");

  mySerial.print("hard reset...");
  digitalWrite(4, 0);
  pinMode(4, OUTPUT);
  delay(10);
  pinMode(4, INPUT);
  resp = Serial.find("ready\r\n");
  mySerial.println(resp);

  mySerial.print("mode1...");
  Serial.println("AT+CWMODE=1");
  resp = Serial.find("OK\r\n");
  mySerial.println(resp);

  mySerial.print("connecting...");
  do {
    Serial.print("AT+CWJAP=\"");
    Serial.print(WLAN_SSID);
    Serial.print("\",\"");
    Serial.print(WLAN_PASS);
    Serial.println("\"");
    resp = Serial.find("OK\r\n");
    mySerial.println(resp);
  } while (!resp);

  mySerial.print("mux1...");
  Serial.println("AT+CIPMUX=1");
  resp = Serial.find("OK\r\n");
  mySerial.println(resp);

  mySerial.print("udp...");
  Serial.print("AT+CIPSTART=4,\"UDP\",\"");
  Serial.print(WLAN_ADDR);
  Serial.print("\",57120,");
  Serial.print(PORT);
  Serial.println(",0");
  resp = Serial.find("OK\r\n");
  mySerial.println(resp);

  Serial.setTimeout(1000);
}
void loop() {
  while (Serial.available()) {
    String abc = Serial.readStringUntil('\n');
    if (abc.startsWith("+IPD,4,16:" + tag)) {
      id = abc[22];
      on = abc[23];
      hi = abc[24];
      lo = abc[25];
      mySerial.print("id:");
      mySerial.println(id);
      mySerial.print("on:");
      mySerial.println(on);
      mySerial.print("hi:");
      mySerial.println(hi);
      mySerial.print("lo:");
      mySerial.println(lo);

      buf[15] = cnt++;
      Serial.println("AT+CIPSEND=4,16");
      Serial.find(">");
      Serial.write(buf, sizeof(buf));
      resp = Serial.find("OK\r\n");
      mySerial.print("send...");
      mySerial.println(resp);
    }
  }
}

SuperCollider test code:

(
//--call&response
var last= Main.elapsedTime;
OSCFunc({|msg, time, addr|
  [\id, msg[1]>>24, \on, (msg[1]>>16)&255, \hi, (msg[1]>>8)&255, \lo, msg[1]&255, time-last, addr].postln;
  last= time;
}, \sti);
n= NetAddr("192.168.1.50", 1112);  //ESP8266 ip address
f= {|id, on, hi, lo| (id&255<<24)|(on&255<<16)|(hi&255<<8)|(lo&255)};
r= Routine.run({
  inf.do{|i|
    n.sendMsg(\tap, f.value(4, 1, i.asInteger>>8&255, i.asInteger%256));
    0.5.wait;
  };
});
)

Note: my new and better way to do this is described in this post: /f0blog/f0led/