However, I didn’t like that the digits had wires between them. This is the 21st century etc. So I set out to make my own version where each digit was completely independent.
Cracking out the trusty Arduino, I soon had a single digit…
While I could have carried on and purchased another 3 Arduini, that would have been a bit flash, and these digits needed to be battery powered (or the no wires thing wouldn’t work). After some digging, I plumped for using the ATtiny2313V as they’re nice and low voltage (and crucially cheap). Using the Arduino to flash the firmware onto the new chip, I soon had my first independent digit!
Things got a bit Matrix and it went into replication…
Then I used some super-expensive circuit layout software to plan the schematic (I built it on Tri-Pad board, hence the groups of 3 connected holes). I also ventured into the realms of sticking stuff on the back of the board for the first time – that’s what the bits in red are.
With that, it was all done bar days of soldering and manufacturing.
The 8 rechargeable, Lithium Ion batteries (costing as much as the entire rest of the build) last about 2 months. It’s well worth the hassle of 6 recharges per year