Instant InfraRed Solar Charged Thermometer

This is my first real gadget i have made that combines the things that i have learned here and on YouTube into a useful device that gives me an instant temperature reading by "pointing and shoot", as opposed to the traditional thermometers you have to wait for them to adjust.
Here i just press the button, point at what you what to know the temperature of and BOOM, there you have it :)

The project runs of a singe AA rechargeable battery and can be charged by leaving the device in the sun and let the 2 solar cells charge the battery up. The button breaks the connection to battery so there is no energy wastage when its not in use.
By pressing the button the circuit is connected and the micro computer starts up, taking the readings from the sensor and displaying it on the screen.

It's all housed in a project box where there have been some holes made for the sensor, button, solar cells and the screen.

It's pretty simple, hope you like and enjoy :)

Here are some links that is useful if you don't know how to do the various bits:
- How to program the ATMega328, Bareduino or Arduino Barebones.
- Connect and test the IR Sensor.

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Step 1: B.O.M

To build this project i used the following:

1 AA battery holder.
1 AA rechargeable battery (Duracell).
1 Project Box (100 x 51 x 22mm).
2 Solar Cells. (3v 50Mah)
1 DC-DC Step-Up Boost Converter (1v -> 5v).
1 Screen (I2C 0.91"128x32 white OLED LCD Display)
1 Diode.
1 Push Button.
1 ATMega328.
1 Mini bread board.
1 mlx90614 sensor.

and a bunch of wires scavenged from all over to hook it all together.

All materials are from eBaY and can be found there at best price if you have the patience to wait ;)

Step 2: Code

Not sure why the code doesn't come out right on the page, so i have linked the Arduino file instead.

Enjoy !

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    5 Discussions


    2 years ago

    Hi, you are connecting a 3v panel to 1.5v cell for charging. Will it not overcharge or damage your rechargeable cell?

    4 replies

    Reply 2 years ago

    Not so far. It has been running for a few months now and I have only had to charge it once. You have to account for resistance and diode, you also have to use a solar cell with 1-2v more that your battery otherwise it won't be able to charge it fully.


    Reply 2 years ago

    Tried this with a OLED 128*32 from Aliexpress but that has only 4 pins-2 powersupply and 2 for clock and data (no reset). I am not getting any display

    do both the SDAs and SCLs from sensor and display go to A1 and A0 of Arduino ?


    Reply 2 years ago

    in addition, i seem to remember that on one of my displays the SDA and SLC was miss labeled too. Might be something to test / consider ?


    Reply 2 years ago

    Does the dispaly working with the example code in arduino by it self ?