My project involves making a fish robot squiggle its tail, controlled by the Nano inside the fish. As I don't want to open the robot up everytime I upload code to take the Nano outside, I used ISP as a way to do it. The robot's motor is powered by a battery, so I unplugged the Uno after every upload.
I'm having an issue that I followed the proper method for ISP code upload as laid out by the Arduino website. In the first time I upload the code and removed the Uno connection from the Nano so the fish can move underwater, everything works out fine. I updated my code and uploaded it the same way, but the fish never moves again.
I have tried putting a capacitor between reset and ground on the Uno, and connecting a 30K resistor between pin 10 (reset) on the Uno and 3V3 pin, but none of these have been successful. This problem is also reproducible, since every day I have had trouble with this issue.
I'll provide more details if anyone needs it. Please help me with this issue. Thanks a lot.