MSP-EXP430FR5994: Cannot get any of the UART examples to work

Are you running loopback or echo? They require different jumper settings.

I am running echo.   FWIW, I have an MSP-EXP430FR2443 at home which I just ran the same UART Introduction Lab successfully on.   The FR5994 is at work.   So I'm gonna take this FR2443 to work tomorrow, to see if it works on the work computer.   And then I'll probably bring the FR5994 home and retry it here, since the FR2443 works fine.

Please let us know your test results. Thanks!

Best regards,

Cash Hao

Hello Cash and Keith,

Sorry for the delay.   I took my FR2433 to work.    I'm able to do all of the UART Introduction Lab no problem!   I brought my FR5994 home and it's the same thing as at work.   Just to reiterate, both comm ports show up, I'm able to load programs onto the FR5994 and even single step them, but the UART Introduction Lab does not work on it.   I can connect my terminal program to the FR5994 application UART at 9600 baud, no parity, one stop bit, no flow control -- just like the FR2443 -- but there are no characters echoed.

I even tried a couple different modifications to the example code where I just directly wrote (i.e., no TX interrupt) characters out the port, and they just never show up in the terminal.   I was thinking about trying to read some of the UART status registers, but I'm not yet familiar with that part.   Shouldn't be too hard to figure out though.

I have a second, unopened FR5994 at home too.   I have a handful (about 8 different) TI MSP430 EVMs all together.  So, I can try that one as well.   I didn't want to crack the seal yet but maybe the one that I'm working with is damaged?  (e.g., ESD or something)

I have looked around the Internet and have seen other people having issues with FR5994 UART but not the same problem exactly, years ago, and I never saw a resolution (e.g., on Stack Overflow, etc.).

I really like the FR5994, so I really want to use it but I just don't know how to do anything meaningful with it in my circumstances without serial I/O to console during development.

Anyway, if you guys have any suggestions, anything that I could read, or try, I'm happy to do so.

Thanks,

Frank

What does your scope show? Are you sure the jumpers are correct?

What is your baud rate?

ISTR that the debugger on the MSP430's can't handle *low* baud rates.

I haven't hooked up a scope/logic analyzer yet.   I thought about it.   I'm following the MSP Academy "UART Introduction Lab" which specifies 9600 baud for the first part of the lab.   It then asks you to adjust the clock dividers to bump it up to 19200 baud.   Works fine with the FR2443, so do you mean that the FR5994 might not be able to do baud rates as low as 9600?

I do see that the UART Introduction Lab does specify the use of the FR2433, so maybe the FR5994 can't do it?   I can try using the clock dividers for 115200 for that matter.   I'll see if I can do that today.

Actually, it can't do lower than 9600, IIRC. 9600 should be fine.

Hey Bruce,

You absolutely nailed it!!   I used the jumpers as you suggested and it's working now!   That is great!

I had briefly wondered about that but, not knowing enough, I didn't consider it.   Besides, I don't even yet know how to select the different UARTs.   I'll get there, soon enough!

I really like that FR5994, much better than the FR2443, so this is really great!

Thanks!

-Frank

BTW, I rewrote the FR5994 msp430fr5994_euscia0_uart_01.c to use UCA0 before I left work.   That way the example works with essentially the same instructions as provided in the UART Introduction Lab.   Was good practice.  Thanks!