Arduino, ESP and 1wire thermometers

This is a simple sketch to read the current temperature from a DS18B10/DS18B20 1 wire thermometer.

I have successfully tested this program on an ESP-12 (ESP8266) using the Arduino IDE.

hardware wiring

This project uses a "console cable" (but any USB to TTL converter is okay). Using an Adafruit like cable:

Black -> GROUND While -> TXD on ESP Green -> RXD on ESP

DO NOT CONNECT THE RED PIN TO YOUR ESP! The red pin is +5V while ESP need +3V3 so either you have a step-down circuit to convert 5V to 3.3V or you'll need another power source of the right voltage for yout ESP.

The connection to the DS18B10 is simple:

1 is GND -> GND 2 is DATA -> GPIO02 on ESP 3 is 3v3 -> +3V3

The circuit also needs a 4.7K resistor between DATA e 3v3.

Software

Here is the source code.

#include <DallasTemperature.h>

const int led=13;

#define ONE_WIRE_BUS 2  // DS18B20 pin
OneWire oneWire(ONE_WIRE_BUS);
DallasTemperature DS18B20(&oneWire);

void setup(void){
  Serial.begin(115200);
  pinMode(led, OUTPUT);
  digitalWrite(led, 0);
}

void loop(void){
  float temp;
  DS18B20.requestTemperatures();
  temp = DS18B20.getTempCByIndex(0);
  Serial.print("Temperature: ");
  Serial.println(temp);

  delay(1000);
}

Testing

Load the program on you ESP. Remember that to set the ESP in "flashing mode" GPIO must be connected to ground at power-up.