Measure 2 temperatures, output to Thingspeak, Tiny webserver, OLED screen
ESP8266 script for measuring 2 temperature sensors DS18B20 Setup tiny webserver Upload measurements to Thingspeak Show data on OLED screen Sense a digital 5VDC input.
Connect two DS18B20 sensors to D5 and add a pullup resistor from D5 to +3V (3k3 - 4k7) Connect a 33k resistor from D7 to GND and 22k from D7 to input (5VDC max). This is a digital input Connect OLED: SCA=D2, SCL=D1, GND and 3V of course :-)
Edit 'secrets.h' to suit your data Edit the HEX uint8_t sensor1[8] and uint8_t sensor2[8] string in the script to your sensor unique number.
The script measures 2 temperature sensors (DS18B20). Updates the OLED screen every 10 secs Refreshes a tiny webserver Updates Thingspeak every 5 minutes.
You will need a thingspeak account with 3 inputs: Sensor1, sensor2 and a digital input.
Application: In my case to measure the data from my forced convection pit. When the temperature is above some 35deg fans wil start to blow and force convection from it. The fans are powered with 5VDC. A digital input on the ESP8266 will register the on/off status of the fans. Hysteresis is some 10-15deg. i.e. When the temperature drops to 20-25 deg the fans will be shut off.