I have had a problem with my Dragon. I am using ATMega328p devices.
I have a ZIF socket soldered to the Dragon. I have short jumpers to the ISP header.
The Dragon works fine interfacing to the uC with ISP. It has no problem setting fuses, reading them back, or reading the Device ID.
But about half the time when I go into debugWire mode and try to come back to ISP mode, I lose the ability to communicate to the uC. Cycle the power by unplugging and re-plugging the USB cable. I close and restart Studio 4. But nothing can communicate to the uC. I try to just start debugging (assuming that it is still in dW mode) but that fails too.
I have to HVPP the device. It appears that somehow the fuses are set to use an external oscillator, but I never changed the fuse after setting them initially in ISP mode, and selected the 8MHz internal osc without the CKDIV.
What might be causing this problem and how do I prevent it from happening again? It is a pain in the neck to set all the 21 wires for HVPP!