Prototype: Light meter based on TSL2591 and Arduino Nano

This is an update of the project. The original project can be found here:

After testing on breadboard, I designed a PCB to fit all of the components together. I also added a LiPo battery as well as a charger/boost converter to keep the light meter powered. Here’s the setup.

Front side of the board with batery turned on

As you can see, it’s a pretty temporary fix, indicated by extra wires and random battery placement. Nonetheless, the lightmeter works as expected the values are quite close when compared with the app on my phone. I will try to compare this with the readings of my DSLR later to furtherly examine the accuracy.

The board has quite some problems. First, I did not consider spacing between the Arduino controller and the OLED display. As shown in the picture, the lower part of the display is blocked by the Arduino and I have to use a couple of pin headers to “lift” the Arduino above the display to create enough spacing between the two. In addition, the USB port on the Arduino is oriented upwards, meaning that the programming cable will block most of the display when I am testing this (see picture below).

The USB cable blocking the LCD

So this wraps up my first working prototype for the light meter and I’m pretty happy about it. Any feedback is welcomed. My next step will be rearranging the PCB layout and flip the orientation of the Arduino.