Grmon not connecting

What are the first bytes after the 0x55 that the GRMON sends to a system. I have a ColdFire V1 with several peripherals connected using the GPL GRIP IP but can’t get my system to come up in GRMON.

I was able to capture this communication after seeing 0x55 sent initially. So, what is the response I should see from the system. Rx is what grmon is sending after the 0x55 bytes and Tx is what should be coming from the system. What should I be getting from the system as a sequence of bytes after it sends that string 0x80 0xFF 0xFF 0xFF 0xF0 to the system.

Did you get it figured out? I had connection issues on Win10, but eventually was able to connect with “grmon.exe -uart COM3 -baud 9600”

As for your question about the response though, I’m not sure.

Nope. Windows complains about finding COM11 which is the right device under Device Manager.

grmon-eval-3.2.13\windows\bin64>grmon.exe -uart COM11 -baud 9600

GRMON debug monitor v3.2.13 64-bit eval version

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ERROR! Failed to open COM11. Device not found!

it only works with the linux version under WSL Ubuntu 18.04.
For linux under WSL, I use this.

./grmon -uart /dev/ttyS11 -baud 9600


Writing the short COM# device name only works for single digit COM devices in Windows. For devices greater or equal to 10 you need to use the full device path, for example \.\com11

Best regards,
Arvid Björkengren

I got it working with Linux WSL but will try that out. One thing is sometimes it takes multiple tries for the grmon to open. Sometimes, I get multiple msgs of UART timeouts. Eventually after 10 attempts it fails. Then hitting reset a few times, usually gets it connected. Is that because it failed to negotiate the communications or maybe something not resetting correctly in my design.