Clearing out your FEZ

I managed (I’m not entirely proud of this) to get my lovely FEZ Micro into a bit of a pickle.  I think I set some pins how they shouldn’t be. The result was that Visual Studio got stuck at “Preparing to Deploy Assemblies to Device” and never got past this. If I tried to use MFDeploy to ping the device it didn’t work. Things looked bad.

Turns out that it is fixable though. The FEZ is a dual personality device. Normally it is a Micro Framework device that accepts programs and runs them. However, it also has a mode where it accepts updates to the internal firmware. TinyClr call this the “’Firmware Updater”. I call it my “Get out of Jail Free Card”.

There is a very useful video from the Fez folks that describes this mode and how to activate it.  First thing you do is watch the video:

Once you have watched the video, installed Terra Term and got the device on the end of the terminal to talk to the terminal program you are ready to clear the memory. You don’t actually want to install any new firmware (so don’t do any of the XModem stuff), you just want to get rid of that nasty Micro Framework program that is stuck in your device. You can do this using the Bootloader program, which is described in Chapter 5 of this guide:

http://www.ghielectronics.com/downloads/USBizi/USBizi%20User%20Manual.pdf

The command you want to use is D.  Just press D and then Y to confirm the erase. You can now exit from Terra Term, reset the device and everything in the garden will be lovely again.

If your PC complains that it can’t find the USB drivers for the FEZ you can find them in the installation directory on your PC once you have installed the FEZ SDK.

I must stress that it is very unlikely that your FEZ will get stuck. I did to something really stupid to break mine, but it is nice to know there is a way back if it does.