MSP430FR5969-SP: How to connect UART pins of Launchpad development kit to RS232

Matthew DeMars

Part Number: MSP430FR5969-SP
Other Parts Discussed in Thread: TRS3122EEVM

I need to connect UART pins of MSP4305969 of Launchpad development kit to the RS232 port of a PC. The MSP data sheet doesn't provide a voltage specification for the UART input and output pins.

Do the UART pins use 3.3-volt TTL signals?

If not, could you provide me with the voltage specification, including recognized logic level voltages?

Do you have any suggestions for what I can use as an interface adapter?

Thank you for your help

over 3 years ago

0 Keith Barkley over 3 years ago

Guru 35580 points

https://www.ti.com/tool/TRS3122EEVM

0 Dennis Lehman over 3 years ago

TI__Guru 60181 points

Hi Matthew,

The LaunchPad already provides a "back-channel" UART to a virtual com port on the PC through the programmer/debugging MSP that is also on that LaunchPad. The RX/TX jumpers are installed by default to support this.

See section 2.3.2 in the users guide.

0 Matthew DeMars over 3 years ago

Prodigy 50 points

Thank you for your fast response, Keith! I am not going to use the UART pins (P2.5 and P2.6) for programming or debugging. This UART interface and pins are going to communicate with another device that has an RS232 port. I can't choose an RS232 signal converter solution until I know the voltage specification of the P2.5 and P2.6 pins, including the range of the low and high logic levels.

0 Keith Barkley over 3 years ago in reply to Matthew DeMars

Guru 35580 points

And we can't tell you that until you tell us your VDD!

Note that the part I linked can handle logic from 1.8 to 5 V, so you are pretty much covered.

0 Dennis Lehman over 3 years ago in reply to Keith Barkley

TI__Guru 60181 points

Hi Matthew,

Were you able to get your connections working?

0 Matthew DeMars over 3 years ago

Prodigy 50 points

My orders for a Launchpad and TRS3122EEVM have been placed with TI but I have not received them yet

0 Dennis Lehman over 3 years ago in reply to Matthew DeMars

TI__Guru 60181 points

Hi Matthew,

You should have received an email from TI requesting that you click a link in the email to approve the order. Did you see that?

0 Dennis Lehman over 3 years ago in reply to Dennis Lehman

TI__Guru 60181 points

Hi Matthew,

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MSP430FR5969-SP: How to connect UART pins of Launchpad development kit to RS232