Please note that the Arduino sketch has two sets of array definitions in the beginning – for LEDs wired straight and LED wired in a reversed order (i.e. LED1 is at the top, not at the bottom). This is just a result of my boneheaded mistake throwing LEDs on the board without taking a second of my time to realize their actual spacial position on the final board. So, the PCBs that I got from BatchPCB ended up with LEDs flipped (LED1 – top, LED6 – bottom) and it was very easy to adjust the software accordingly. But if you’ve built your POV display using the original schematics (here it is on the left, one more time).
St. Patrick’s Day is coming up and I thought it’s already time to update the original Valentine’s Day POV display with a new message and make use of the second PCB I had done at BatchPCB. Also, fortunately, John “smeezekitty” (the author of the Attiny13 core used for programming it in Arduino IDE) stopped by my blog and pointed out to an issue with the original firmware, which prompted me to take another hard look at it and the result has been a saving of whopping 20 or so bytes – it was just enough to fit the word “BEER” which, as I mentioned in the original post, we did not have any space in flash left for. Well, now we do and below is the new software
I have tried to comment as much of the code as I could in case you are making adjustments.
There’s still some space for an even longer message now although it’s getting really hard to fit them into the physical space now – since this is an oscillating POV display, you are limited by the path your arm is plotting while going back and forth – it’s probably only about a foot (30 cm) before it starts looking like a pretty vigorous cardio exercise In other words it’s very unlikely that it’s going to be very convenient to swing a POV display with “I ❤ HOMEWORK” even though there’s probably just enough memory left in Attiny13 to fit it all in.
OK, enough talk, here is the new code with the “I ❤ BEER” message.