Uploading code thru ISP Issue

Hello everyone,
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.


Try putting back your known-good code.
Or try re-uploading it, maybe something went wrong there.

I mean that even if I keep the same code, the same issue still happens again. I unplugged the Uno to switch to using batteries as a power supply, and the issue keeps popping back up

I noticed some other things. When I plug the UNO which is also my ISP Programmer and have it connected to the Nano, the robot moves just fine. However, when I removed the UNO and switch to battery as a power source, nothing happens. Please help !!! Thanks

That quite strongly points to a power issue. And that can be anything. Dead battery, loose wire, too low voltage...

i have another issue with ISP programming. There are several times that my laptop just suddenly shuts down after ISP uploading. Has anyone ever encountered this before and please help!!! Thx

We won't be able to help until you post a complete wiring diagram (hand drawn, not Fritzing).