This is a little project I made to read a couple of temperatures.
The temps that have been read are posted to thingspeak and displayed on a lcd screen.
| Arduino | ESP8266 | LCD | External 3V3 | External 5V |
|---|---|---|---|---|
| GND | GND | GND | GND | GND |
| VIN | - | VIN | - | 5V |
| D2 | RXD | - | - | - |
| D3 | TXD | - | - | - |
| D4 | - | RS | - | - |
| D5 | - | E | - | - |
| D6 | - | D4 | - | - |
| D7 | - | D5 | - | - |
| D8 | - | D6 | - | - |
| D9 | - | D7 | - | - |
| - | VCC | - | 3V3 | - |
| - | CH_PD | - | 3V3 | - |
Note on LCD
- Wire the backlight GND to GND of external 5V
- Wire the backlight Vin to 1k Resistor to Vin
- Wire a 1k potentiometer between Vin and Contrast Voltage
- Wire RW to GND
Also your API key has to be inserted in the correct place.
If you have more channels or fields at thingspeak you have to change the GET request. You have to figure out for yourself how to wire your thermometers
Also you have to figure out the formula for the thermometer