CCS/MSP430FR2532: UART Communication for serial Monitoring

Aref Smiley

Part Number: MSP430FR2532

Tool/software: Code Composer Studio

Hi All,

I am new to MSP430 and I am trying to learn. I have two pressure sensors working with I2C communication. I have my MSP430FR2532 on a PCB with 2 pressure sensors. There are 6 wires coming out of the boar for programming the MCU and UART communication (VCC, Ground, TXR, RXD, SBWTCK, SBWTDIO). I was trying to monitor the results in the serial port of the CCS through UART. I used this code for UART configuration and initialization :

everything works perfectly and I can monitor the results of the two pressure sensors on the CCS terminal with suggested UART_BAUDRATE. There is only one issue with the system:

If I choose longer wires (TXR, RXD) for the board, the CCS terminal does not work anymore and shows some random things. for up to 50 cm length of wire the system works perfectly, If I go beyond 50 cm, It stops communicating.

Any Idea or suggestion?

Thanks

over 7 years ago

0 Keith Barkley over 7 years ago

Guru 42215 points

Do you have a ground hooked up? It is unclear just how you are connecting to the PC. Are you using some sort of serial adapter? I hope you are not plugging your Launchpad serial directly into that rare bird, a true PC serial port. They are RS-232 and might output voltages that will damage your board.

0 Aref Smiley over 7 years ago in reply to Keith Barkley

Intellectual 300 points

Thanks for the response.

Yes, the ground is hooked up correctly. Basically I use the a serial adapter of a msp430 launchpad. Please see the attached picture.

sometimes, when I disconnect the RXD wire, it starts showing the results and it happens when the wires are long (colorful wires) (longer than 50 cm); with short wires connection, everything is working perfectly!!!

0 Keith Barkley over 7 years ago in reply to Aref Smiley

Guru 42215 points

3.3 V serial is not really designed for long runs. You need a differential receiver and twisted pair - like RS-232 or 422.

0 Aref Smiley over 7 years ago in reply to Keith Barkley

Intellectual 300 points

Thank you so much. Is this what you are suggesting:

en.wikipedia.org/.../Differential_signaling

I was thinking 2 m of wires should be fine. But I will try your suggestion.

Thank you again,
Aref

0 Walter Schnoor over 7 years ago in reply to Aref Smiley

TI__Expert 7535 points

Hi Aref,

Have you made any progress towards resolving this issue?

Regards,
Walter

0 Aref Smiley over 7 years ago in reply to Walter Schnoor

Intellectual 300 points

Hi Walter,

I have not had a chance to do it yet. I will try it sometimes next week and will update my post.

Thanks again for your suggestion.

Aref

0 Walter Schnoor over 7 years ago in reply to Aref Smiley

TI__Expert 7535 points

Hi Aref,

I'm going to close this thread for now. If you have additional questions, feel free to post again and/or reference this posting.

Regards,
Walter

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CCS/MSP430FR2532: UART Communication for serial Monitoring