It’s been a long time since I wrote any updates about my IN-3 matrix project. Whilst I haven’t had much chance to work on it it has come a long long way from the original 4×4 tester.

I built an oak frame, machined an mdf board and attached 128 bulbs. Then I started the long process of wiring up each bulb to the PWM driver boards. In hindsight, I should have designed some kind of PCB strip to connect the bulbs to. This would have saved many hours of labour and been a lot neater. As it is each row of 16 bulbs takes about 1 hour to wire. Very boring so next time I know what to do!

I opted to buy a high(ish) voltage supply from eBay, the display can draw a lot of power when fully lit so despite having literally hundreds of high voltage driver boards for my IN-9 kit I figured to play it safe!

I am still only running some test code to make sure the bulbs light up and in the right order. I’m using an Arduino and the Adafruit Adafruit_PWMServoDriver library to communicate with the PCA9685 PWM drivers. Once I find a couple of hours to finish off the last two rows I’ll focus on what to use as a controller (probably the Teensy I’ve had laying about for 3 years) and actually write some proper firmware.

I’ve also now added a Github repo with all the hardware design files (DesignSpark PCB) for the driver boards and arduino sketches. I’ll continue to add to it as I progress.