Trouble Programming 3pi using Atmel AVR programmer

I recently purchased a 3pi robot from Pololu. I decided to use Atmel Studio and an Atmel AVR programmer that we had handy at the University.
When I connected my device and programmer, I got a message from Atmel Studio that said “to enable debugging, set the fuse DWEN”, and I accidentally clicked yes.

Now, when I try to program the 3pi using Atmel Studio, I get the message “unable to enter programming mode”. Specifically, I click on DEVICE PROGRAMMING. I select
Tool:JTAGICE3 (which is the tool that I’m using)

I then click Apply. I click on Target Voltage and I get 5V. However, when I click on Device Signature, I get the mesage
"Unable to enter programming mode> Please verify device selection, interface settings, target power and connections to the target device".

The pre-loaded program on the 3pi is working well, and all functions of the robot seem to be okay.

Can someone please help me with this problem?



I split your post into its own topic because it has nothing to do with our new DRV8825 Stepper Motor Driver Carrier. In the future, please post a reply to a relevant topic or start a new topic.

I am sorry you are having trouble with your 3pi. Since you enabled the debugWIRE interface by changing the DWEN fuse, you probably cannot talk to the AVR using the ISP interface anymore. In the Device Programming dialog box, for “Interface”, instead of selecting “ISP”, you should try selecting “debugWIRE” or something like that (I don’t know the exact text you will see in Atmel Studio). Unfortunately, there is a capacitor on the 3pi’s reset line (C26) that will probably prevent the debugWIRE interface from working, and you will need to remove it. Other customers have been in the same situation as you. Please see the advice I wrote in this post:


Thank you David, and sorry for posting in the wrong location. I hate to admit it, but I simply could not figure out how to start a new post.
I’ll follow your recommendation. Thanks again.