Serial Problem with Tiva C Launchpad

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Hunting Primes with Microcontrollers

Mike SzczysMike Szczys 03/23/2014 at 20:332 Comments

I'm getting really weird performance from the Tiva C Launchpad when using the UART. The board itself is an ICDI programmer but it also serves as a serial terminal at /dev/ttyACM0. The problem I'm having seems to be with synchronization. Some of the characters will be dropped, but other times I get complete gibberish. At any rate, I have the firmware looping at after a minute or two everything is rock-steady, but the unstable performance returns once again after power-cycling.

I was developing this via SSH, with my production machine in the other room while I was on the sofa watching March Madness. I pulled out an FTDI breakout board; only needing to hook up one wire from TX on the Launchpad to RX on the FTDI (both are running from USB on the same machine which serves as the ground reference).

Has anyone else experience this serial performance issues before?


Mike Szczys wrote 05/08/2018 at 14:55 point

Yeah, minicom is my go-to. I haven't tested with other terminal software.

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Sagar Shubham wrote 05/08/2018 at 08:16 point

I faced a similar issue, dropped characters followed by complete gibberish. High baudrates was my initial guess for the issue, but I brought it down to 9600 but the issue persisted. 

The only solution I have is a soft reset, using the UART Receiver interrupt. Things go back to normal then.

UART was only a way to know the flow of my code, so I added an SPI OLED instead and removed my dependency on UART.

Of course, there is little on TI support to know for sure what happens.

I tested that on 4 different boards, same issue.

What did you use on PC side for console? I had tested with minicom only. Maybe windows might be better.

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