Esp32PreciseTemperature

A precise temperature sensor setup for Domoticz

July 21st, 2018 Updated to use with OTA and MQTT

The sketch named temp_met_ir_OTA_MQTT2 has been updated to use with OTA (over the air updates) and publishing the temperature through MQTT to your domoticz system. The temperature is send at least every 10 minutes or when a change of more the 0.2C occurs. Once an hour the ESP32 will restart, sometimes it will hang and the restart prevents that) In this version you need two files temp_met_ir_OTA_MQTT2.ino and credentials.h All your passwords are in credentials.h

Built a Precise thermometer to use with Domoticz

Most temperature sensors are based on an DS18B20 sensors, the disadvantage of this sensor is that is heats up itself. This results in a higher temperature. By using an InfraRed sensor you are able the measure the temperature in the field of view of the sensor. (you sensor could be 40C (104F) in the sun, but in field of view the temperature is on 21.2C (70C) If you are using the sensor for controlling something else the precise temperatue could benefit. The temperature are very fast because there is no cooling or heating of the sensor in our object measurement.

Materials to use

Board: DOIT ESP32 DEVKIT V1, 80Mhz, 4MB(32Mhz),921600 None op COM3 Available at Banggood (about EUR 5.50)

Sensor: MLX90614ESF Infra red non-touch sensor Available at Banggood (about EUR 10.00)

Where to obtain the parts and materials

Banggood is where I buy all my parts Visit Banggood

Wired connections

From	-	To
MLX 90614	--	ESP32
SDA	->	D21
SCL	->	D23
Vin	->	3v3
GND	->	GND

Set up Domoticz

Add Hardware (if needed)

Click Setup -> Hardware

set Name ="Virtual Sensor"

set Type ="Dummy (Does nothing, for virtual device only)"

set Data Time ="Disabled"

Click Add

Click Create Virtual Sensor

Type a name "whatever you like"

Set Sensortype to "Temperature"

Find Idx of device in Devices

Click Setup -> Devices

Click Idx(the top row of the label so it sort the high to lowest)

write down the Idx number

Needed settings

To use the Domoticz API you must base64 encode your username and password see the link below

const char* ssid     = "SSID OF YOUR WIFI";
const char* password = "PASSWORD FOR YOUR WIFI";
/** username and password for Domoticz
 *  use http://codebeautify.org/base64-encode to encode both
 */
String user ="ENCODED_USERNAME";
String pw="ENCODED_PASSWORD";
/** IP and Port to Domoticz */
String domoticzIP="IP_ADDRESS";
String domoticzPort="PORT";
// The Idx of the domoticz device used string to easy adding to getstring
String domoticzIdx ="IDX_SEE_DEVICES_IN_DOMOTICZ";

Project Photo

Sensor: Actual temperature of the sensor, object is the temperature the sensor faces in this case my room

Temperature data

The data is sent every minute at the 20th second (don't want to interfere with timed events that start on whole minute) If the temperature changes more then 1C or 2F the change is send direct. In the webinterface the data from Domoticz is refreshed every 10 seconds. So you may have to wait a few seconds to see the change on the screen.

SpoturDeal/Esp32PreciseTemperature