Electronic – arduino – Jtag debugging AVR


Can anyone advise what hardware and software is required for debugging AVR in circuit.

Best Answer

Normal ISP programmers have no JTAG debugging capabilities. For this you will need slightly more expensive hardware. A JTAG in circuit emulator will enable you to let your circuit communicate with your PC while you are running the firmware. This way you can set breakpoints, watch the memory, enable/disable pins and see the exact status of your micro controller. The ISP programmers from EMSL and Adafruit will not let you do this.

One of the cheapest programmers that have in-circuit emulation capabilities is the AVR Dragon. It will cost you about $50,-. It is cheap for a reason though: it's too easy to overload the circuit and break the programmer. If you get one I recommend that you find some form of protection like a DragonRider or a DragonHide. (I already killed my first dragon which is surprisingly easy to do)

A more robust solution would be an AVR-JTAG-ICE-MKII but this thing is much more expensive.

You can also try and build one yourself.