U can see the test with this usefull tool

Supplies

u need:

2pcs DS18b20 digital temp sensors, for air or liquids

Wemos d1mini v1-v4

1led

4.7k resistor

220 resistor

test pcb

Step 1: Why?

I used this old and reliable controler from almost 20 years, and solar panel sensor, analog , its not working well anymore.

That's why I decided to make this version, with digital sensors, alarms, and web page to read the temp, even remote.

we have 2 ds put in paralel, on D7 input

3.3v supply voltage

4.7k resistor pull up data to Vcc

output signal to the pump, and monitor led with limiting resistor

the software is very simple, I've explained in the video, and u can read temp in serial monitor

I made advanced version of this v1 thermostat, with a lot of new features:

-buzzer for audible alarm

-transistor for the relay

web page to monitor the temp

design for pcb

and beacuse the software of v2 was expensive, I decided to recover a part of money through paid subscripsions on my YT channel for the 1 year.

but v1 is working and is very useful.