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MT32-Pi Issue "UART framing error!"
Posted: Sat Jun 19, 2021 1:17 pm
by immaburr
Hello everyone,
Seeing this error on the LCD screen when trying to start the MT32-pi. Connected only to the USER I/O port:
"UART framing error!"
It's also jumping through some other errors but they are too fast to read. If I comment out PSU errors from the wiki the error messages cycle through the above and something "break".
Same issues if I add the PI power supply but didn't leave on too long just in case that was too much voltage. I am using a digital I/O 6.0 revision if that's potentially any factor? Possibly an issue with the I/O board itself?
Any help would be greatly appreciated!
Re: MT32-Pi Issue "UART framing error!"
Posted: Sun Jun 20, 2021 2:04 am
by legacypixels
How long is the cable you are using?
Also, you can use a separate power supply for the pi safely if you turn the mt32-pi power switch OFF- that will disconnect the power lead from the MiSTer.
Re: MT32-Pi Issue "UART framing error!"
Posted: Sun Jun 20, 2021 2:32 pm
by immaburr
legacypixels wrote: ↑Sun Jun 20, 2021 2:04 am
How long is the cable you are using?
Also, you can use a separate power supply for the pi safely if you turn the mt32-pi power switch OFF- that will disconnect the power lead from the MiSTer.
I'm using a USB 3.0 cable that came with the MT32-pi hat. If I turn the hat off and use the power supply with the PI I get the same errors if I'm also connecting the USB User I/O port.
If I disconnect the USB cable from the I/O port and power on it comes up fine. This sort of leads me to believe this might be an I/O board issue.
Re: MT32-Pi Issue "UART framing error!"
Posted: Mon Jun 21, 2021 11:13 pm
by legacypixels
Hmm, OK.
Any chance you can post a picture of your I/O board?
Re: MT32-Pi Issue "UART framing error!"
Posted: Tue Jun 22, 2021 10:16 pm
by legacypixels
Also, try plugging your USB cable in the other way around.
Re: MT32-Pi Issue "UART framing error!"
Posted: Wed Jun 23, 2021 1:08 am
by immaburr
I've attached shots of the I/O board I'm using. Please let me know if you need any closer shots.
Re: MT32-Pi Issue "UART framing error!"
Posted: Wed Jun 23, 2021 11:20 am
by Nat
Have a check for bridges / shorts on resistor networks RN12, RN13, RN14, and RN15
Looking at the pictures it seems you have a bridge on RN12 see where I've marked it on the below image.
- Possible RN12 Bridge IO Board.jpg (615.61 KiB) Viewed 3597 times
Re: MT32-Pi Issue "UART framing error!"
Posted: Thu Jun 24, 2021 12:05 am
by immaburr
Nat wrote: ↑Wed Jun 23, 2021 11:20 am
Have a check for bridges / shorts on resistor networks RN12, RN13, RN14, and RN15
Looking at the pictures it seems you have a bridge on RN12 see where I've marked it on the below image.
Possible RN12 Bridge IO Board.jpg
Thank you for this! I reflowed the contacts and tested and all seems to work now.
Thank you again for everyone's help!