Thomas

Did you see this? https://github.com/hydronics2/2019-easy-bee-counter/tree/master/instructions/archive " I made a few mistakes on the first version (v0). The 74hc165 is not a true SPI device. It doesn't have a tri-state buffer...

If you are using the PCB v1 then I already made the changes and you can just swap out the shift registers and it will work. 

damn... that's right.... the HC595 has a different pinout!... so that's not an easy solution... that's too bad. I should have probably designed a tri-state buffer into the design like...

Great, bit-banging was a good idea. On Thu, Feb 4, 2021 at 6:08 AM Christophe45 wrote: > I succeeded with the Bit-Banged SPI with your sytem and using normal SPI...