I picked up a FrankenCNC at a very good price. The frame is an overkill solid build with OpenBuild high torque stepper motors, a VFD spindle, 2 xPro V3 controllers and 2 PSUs... But sadly lacking niceties like limit switches and when he mounted the laser to it he cut the spindle wires rather than open the drag chain, I did mention that I got it at a price that I more than happy with. After downloading GRBL .9 I had the stepper motors working then bright me reads the info on upgrading to Grbl 1.1 and away I go. Well suffice to say it did not go the way I planned. I now have a nicely bricked controller. No problem I drop in the second one and it to my endless surprise it appears to come pre-bricked. Does anyone know of a surefire way to recover these controllers. heck I'd even take a hail Mary chance. I do plan on going with an Open Builds controller but I want to make sure that "it weel cut" (too many episodes of Forged in Fire). Thanks in advance.
Some of the later 8bit xPros used a slightly odd microcontroller (atmega328pb instead of the more usual atmega328p) so see xPro Bootloader corrupt. How to reflash? Keywords: atmega328pb vs atmega328p, usbtiny, Arduino for some tips on how to re-bootload it. You'd need an AVR flash tool (hardware). Once it has a bootloader again you can flash Grbl, but also making sure to use 328pB compatible commands for avrdude. Using commands and tool for the non-b chip will brick it sometimes (xloader especially, it doesn't check the signature)
I managed to recover both boards. I used AVRDude and an USBASP programmer . I flashed optiboot_m328pb.hex as the boot loader then grbl_v1.1h.20190825.hex and "THEY ARE ALIVE". Thanx for the help
