OK, I got it to work, but it’s a little strange. I found that the port 0 pins behave strangely (I have 3 port 0 pins that I want to drive this way).
For any port 0 pin, I found that I need to FIRST initialize it to output high. After setting it output high, I’m able to switch it back and forth to hi-z and output low. Note, my code is also using 0x100 instead of INPUT_DISABLE.
For the port 1 pin, it works without the first step.
My original code initialized it by setting it high-Z directly, but this apparently gets it into a state where it won’t subsequently drive low.
Thanks for the tips!
