Today I transfert the same code from “arduino uno” to an “ESP8266 (rev3)” and the Digits display wrong informations (random). I tried different pinout of ESP8266, digital output (D1,D2,D3 and D6,D7,D8) for “segmentClock”, "segmentData, “segmentLatch” .
Do you know if your large digit driver could work with ESP8266 ?
"For what it’s worth, I just tried the Large Digit Driver with a 3.3 volt Arduino and the shift register seems to be fine with a 3.3 volt supply and I/O so you’re probably OK to use these on a Pi. Just connect the Large Digit Drivers 5V pin to 3.3 volts and your 3.3 volt I/O will likely be fine. "
I was powering the large digit Driver with 12V and 5V and I/0 where in 3.3V, not the same reference. So i put a power of 12V and 3,3V and it works !
But now instead of 2 large Digit, I’m using 4 large digits and I notice that the brightess is decreasing from digit 1 to 4. (2 digits the brighness was ok)
Glad you were able to solve the issue getting digits to work!
For the brightness decreasing issue, try feeding 12 volt power in at the first and last digit rather than just at the first digit. The reason for the decrease in brightness is each large digit driver has a small amount of resistance in the copper traces on the board and that starts adding up as you daisy chain boards. By connecting power at the first and last digit, you increase the voltage to the last and second to last digits and that should even out the brightness.