I've got a Christmas light display in my front yard that I setup using a teensy 4.0 and FastLED. It's worked well. I also have a raspberry pi 4.0 at the tree that I use to modify the code and upload to the teensy. (I access it over NoMachine over wifi.) Sometimes some of my sketches will 'crash' the teensy, or at least that's what I think is going on. After I load them it doesn't work and I can't program again without going out and pushing the program button on the teensy. That is a bother that I thought I could remedy by hooking up one of the GPIO pins on the Pi to the program pin on the teensy. I believe it is active low. I wrote a little python program on the Pi to toggle pin 8. I thought the GPIO pins are high impedance, but whenever the pin is connected the Teensy reboots constantly. Am I doing something else wrong or do I need a pull-up resistor on the program pin?