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Newly received device not working


Hi all,

I want to start devloping for IoT. Ordered the FEZ from Mouser but they delivered an old version I suppose. After receiving the device I simply want to test Led blinking but the debugger complaint that it could not initialize. After checking the firmware version with TinyConfig it said version 0.11 while this had to be I suppose. Then I tried to click Update Firmware button but after that the status stays at rebooting for ever. May be I have received a defective device and had to return to Mouser?

Hope you can help and tnahs in advance!

Best Regards,


Ok, on another computer with Windows 10 it updates the firmware!


Glad you got it to work. We have frequent firmware releases so it is normal to need to update the firmware on a new device. You will even update again once we another release.

We are here to help and enjoy your FEZ :slight_smile:


Thanks for your reply!

Yes, everything works as expected now! I will try WiFi later!



Make sure you update the WiFi firmware also. You need a USB to TTL serial adapter to attach to the FEZ board to program using the ST Micro tools. Look at GHI site on updating the WiFi firmware. I posted some notes on another forum entry. It looks painful, but it really is not. This is a great board, in my opinion!


Hi Pashpe,

I have ordered an USB to TTL serial adapter but not the one that is recommended. I hope this cheaper one will also work!. I have also ordered wires with pins and the missing PCB connectors which had to be soldered on the FEZ board.

I hope I am able to update the WiFi firmware.

Best regards,


Hi all,

I have received the USB to serial adapter ( but no success. The FEZ firmware could is erased.

But the firmware of the WifI module could not be uploaded with ST Flash Demonstrator, Th error is: “No response from target, the boot loader can not be started. Please verify the boot mode configuration anf the flash protection status. Reset your device then try again…”

May be WiFi is defect?

After this I have uploaded the FEZ firmware again without updating WiFi.

So I was only able to do one step of the instruction!

Any ideas?

Best Regards,


Maybe a 3.3V is working better. But I’m not a specialist. I’ve updated my with 3.3V version not 5V.


you need to tell us what connections you used, where. Often with UARTs you need to reverse the RX and TX to what you would expect (search UART DYSLEXIA for a laugh). And I would just not connect the 5v. While I don’t have a FEZ device I have used PL2303’s for many other serial port connections, so expect this to work (ie it’s something you’ve done, or not done, that’s the likely cause, not likely the wifi is defective)


Hi Breet,

Thanks for your message. But I can connect to the Boot Loader with Terra term. This was used to erase the FEZ firmware. I think this proves that TX and RX are correct connected. Furtermore I didn’t trust the USB to RS232 adapter so I have found an old RS232 cable and removed on connector and connect it to the FEZ. Same results however. So I suspect the WiFi modul is defect.

Best Regards,


Just make sure the adapter is 3.3V compatible and it should work w/o issue. The FTDI adapter recommended is a bit pricey, I agree.


Hi Bauland,

Also thanks for your message! I don’t understand what you mean. I have first soldered pins in H1, RX, TX, GND and connect H1 (BOOT0) to a 3,3V with a cable as instructed.

Or do you mean 5V form the USB?

Best Regards,


RX serial adapter <-> TX wifi module
TX serial adapter <-> RX wifi module
GND serial adapter <-> GND wifi module
Boot0 wifi module <-> 3.3V of FEZ
Hit Reset
From ST Flash Demonstrator, baudrate is 115200 or slower.

Doesn’t work ?

  1. Swap tx, rx
  2. Check your serial adapter. Can use teraTerm, short TX and RX together and try to send any character from TeraTerm, you should receive what you type.


Assuming you had the FEZ powered via USB plugged into your computer, and you then had the USB to Serial TTL cable plugged in? Be cautious as the FEZ will show up as COM port when in boot loader mode. And this is correct behavior. Teraterm will connect and you can issue the E command to erase. You are not connected to the WiFi at this time, however. You can only connect to the WiFi of the ST module via the pins on the H connector (4 pin connector). Once the WiFI is in boot mode, you can’t talk to it with Teraterm. Only the ST Flash Utility Demonstrator program will talk to the WiFi module when the WiFi module is in boot loader mode. I can’t emphasize enough to be sure to hold the FEZ reset button (big black button) down BEFORE you plug the FEZ in. The cable plug in order is: FEZ USB cable, then USB->TTL cable, then start the STM Flash Demonstrator and don’t release the FEZ reset button until you have made a connection with the STM Flash Demonstrator. Good Luck.


Hi Pasphe,

Now I understand what had to be 3,3V. It is the USB to RS232 adapter, The straight RS232 connection didn;t work either with Flash Demonstrator. It did work with Terra term and connected to the boot loader of the FEZ.

Thanks for your message!



Hi Pasphe,

Thank you again! What a great forum!

I will try to hold reset button later. I haven’t done this because it wasn’t in the GHI instructions.

Best regards,


Nope, that doesn’t confirm that. Interesting assumption, pretty close, but not guaranteed to be correct.

Tell us this, so we know what you have connected, where, and when in the process.
Check Device Manager, did your serial port device load the correct driver, and what COM port is it?



If I hold the reset button than de COM port of the bootloader is no longer visable in the ST Fash Demonstrator. This is tested with RS232 cable (not with the USB to RS232 adapter). I will test with USB->RS232 adapter later bacause this didn’t work with Dell server. I will try again on computer with Windows 10.



Hi Brett,

What was done so far:

  • Started TinyConfig and place the board in BOOT mode.
  • Connected H1 (BOOT0) to 3,3V, RX to TX of computer, TX to RX of computer and didn’t connect GND.
  • With Terra Terminal erased the firmware of the FEZ board. Terra Term saw on one computer COM3 as bootlader connection and on another COM4 (also once COM5).

BTW TX and RX of the computer was from USB->RS232 adapter or from the RS232 cable in the computer.

Best regards,


what other connections to the device do you have? if you have two cables going to it… you need to be clear what connection matches to what COM port and what device it presents…