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HELP with Save the program


I am thinking to make a T-shape cable to take the power from USB connector and use it, removing one battery at programming time.

Any case, thanks a lot for your time.


Jose Carpio.


Hi Guys,

IM still new at this so I dont really understand all the fuse settings, connections and etc. i have a 3pi robot that i have had the pleasure of playing with and programming it with the different sample programs. However as of recent i cannot seem to erase and save a new program to the 3pi using the avr programmer. I did accidentally press the fuse section of the avr programmer and heard a beep. After that i can no longer uplaod new programs to my 3pi.

Is there a way for me to check if my fuse settings are correct? Not sure if this iswhat is causing my issue tho.



Hello, Rod.

I am sorry your 3pi is not able to be programmed. Depending on which fuse(s) you changed, you might be able to get it back in working condition. Are you able to use Atmel Studio to connect to your 3pi? One way you can test this is to connect your 3pi like you have been, then click Tools > Device Programming, select your programmer (which you were using before and should be called STK500) from the dropdown menu under Tool, and then click Apply, and Read. If you can read your 3pi, you should hear it make a noise and the Device signature and the Target Voltage fields will be populated.



Hi Jon,

Thanks for the response. Yes I believe Atmel Studio is still able to since I can do the above mentioned. Where the issue for me though is when I program the 3pi with changes to the code for example, it doesn’t change the behavior of the 3pi.

The changes i made to the code was to make it go back to the start of the maze. I did this by changing the maze solve portion of the code to reverse the loop and adjust the turns accordingly. I was tweaking around the values more and more since I was missing the turns. After one of my tweaks i accidentally pressed the fuse button and the 3pi made a sound. But i couldn’t tell if anything changed so i continued to program my 3pi through the usual steps (memories > program) wherein it still also made a sound and the 3pi robot restarts. But when I let the robot run the maze, it doesn’t seem to reflect the changes I made.

I know it could very well be possibly the codes I am changing but to make sure i reverted the changes to the original state of MazeSolving to test it out but my robot still behaves as per my last code change prior to the accidental fuse button press. So I was thinking if i might have accidentally changed a fuse setting wherein the robot doesn’t delete my code and apply the new one? If there is a screenshot somewhere to check if i can compare each setting to see if i have everything correct would be great as a first step of ruling out that i didn’t inadvertently change something.




The 3pi will play a sound as soon as the “Fuses” section of the Device Programming window is clicked (i.e. no fuse settings need to change for the 3pi to play this sound). Also, it is not entirely clear that you are changing your code substantially enough to expect a noticeable difference in behavior from your 3pi. So, your 3pi might be okay.

Can you try loading much simpler code by following the instructions under the “Compiling an Example Program” section of the Pololu AVR Programming Quick Start Guide? If your 3pi is not able to be programmed with that code, do you see the “Build succeeded.” message in Atmel Studio (there is a picture of what that message looks like in the section I mentioned above)?



Hi Jon,

The 3pi seems to be working again now and I think it was really just something with the code. I just removed the whole portion i commented out and it was ok. Not sure why the commented portion was still being read but i’ll just try to redo that whole portion of the code i was trying to play around with.

Thanks for the help!