It comes with AT firmware. It is programmed using Arduino IDE. NodeMcu firmware is flashed. Link to flasher --https://github.com/nodemcu/nodemcu-flasher.
- While Uploading the code GPIO00 should be grounded.
- Choose board Nodemcu 1.0(Esp12E module).
DS18B20 sensor is used in this project. Connect it to the esp8266 as per circuit diagram. 4.7k resistor is needed from data pin to vcc for pull up.
I2C OLED display is used here. GPIO14 is SCL and GPIO02 is SDA.
ESp8266 OLED driver for SSD1306 library can be downloaded using Arduino library manager.
It is a heartbeat sensor from pulsesensor.com. Signal output is given to 2.2k resistor and then to adc pin of esp8266. 1k resistor is added from adc pin to ground. This voltage divider resistors are required as adc pin range is 0-1v. Pulse sensor is powered using 3.3v power supply.
Data collected are sent to thingspeak.com server using Thingspeak API. After creating the channel, we have to copy write api key to our program. Thingspeak app is installed on mobile phone. App requires read api key of your channel on thingspeak. once we configure the app,data is shown on app.
Using IFTTT service we can act on data. Thingspeak thingHTTP app is created and it is configured to request the IFTTT service when certain condition is met. For example if temperature is grater than 35~c, it can send email, sms or push notification. IFTTT maker service is used as Applet.