Tag Archives: pullup

Raspberry Pi serial and the importance of pullups

Another day, another lesson learned. My Zolatron 64 6502-based 8-bit computer uses serial for its main I/O. One day I may add video output and keyboard input. But for the time being, I’m happy to talk to it via a terminal from another machine. So far, that other machine has been my electronics workbench computer – a LattePanda Alpha. And… Read more »

SmartParallel: pulling up and pulling down

It’s never a good idea to let signals float around in the no-man’s land between the high state and the low state. This is why we so often use pullup and pulldown resistors. You set the line to a known, definite state by default and then switch it as necessary. Some uses of pullup and pulldown resistors are obvious. Some… Read more »