published earlier on this blog.
Meanwhile I have also completed the onboard font with 0-9 numbers and 7 possible symbols (check the ASCII table and you will see there are seven "holes" between number 9 and capital letter A).
For this first release I have left out current limiting resistors on anodes, so I rely on the average current since in the worst case each pixel is ON only 1/7th of the time. The resulting "component" is compact and TIL305 displays can sit next to each other without short circuits.
With proper fuse settings the ATtiny4313 works between 1.8 V and 6 V, so intensity can be controlled through either "pixel ON time" or DC power supply (but not through PWM dimming).