Measuring temperature and showing on LCD works

After my blinking led project using Arduino I now moved on to my real project: controlling the cooling system. I am approaching this step by step. The first phase was measuring the temperatures and showing them on a screen.

First I quickly attached some wires to the LCD to connect it.

16x2 LCD solderen

I created a sketch that just showed some text on the screen.

Test tekst op het scherm

Next I added dummy values representative for the end result. From left to right it will show battery, controller and motor temperature. On the second row the speed of the pump in that cooling loop.

Dummy waardes op het scherm

To measure the temperatures I wanted to use a DS18B20 sensor. It took me a while to find one that was mountable with a thread.

temperatuur sensoren DS18B20

Next I updated my sketch to show actual temperatures. That however caused the LCD become very instable and scrambled.

Scrambled text LCD

When I did not define Serial.begin it did work (I found that out 03:00 in the night), but was of course not the structural fix. In the end it turned out I used the Tx communication pin (pin 1) for the LCD. After fixing that it worked flawless.

Wiring LCD

Dynamic values working

Currently the screen shows tree actual temperatures.

The pump speeds are still dummy and the temperatures are not used for anything yet. Next step will be adding a function that translates a measured temperature to a pump speed.

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OldVolvo is a classic Volvo hobby blog by Lars Rengersen.

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