TCA9535: VCC not set error during flash process — I/O Expander User Guide (Chapter 5.3, Step 8 & 9)

shahajahan m

Part Number: TCA9535
Other Parts Discussed in Thread: IO-EXPANDER-EVM

Hello TI Team,

I am referring to the I/O Expander User Guide, specifically Chapter 5.3 (Flashing procedure), points 8 and 9, which describe the steps for flashing.

During this step, I am encountering a “VCC not set” error message when trying to execute the flash process.
Could you please clarify:

What exactly “VCC not set” indicates in this context?
Is there any configuration or power sequence required before flashing?
Are there any known conditions (for example, missing pull-ups, incorrect I2C address, or voltage levels) that could cause this issue?

If required, I can share my hardware setup details and the exact command or tool I’m using for flashing

7 months ago

0 Tyler Townsend 7 months ago

TI__Guru 60958 points

Hi Shahajahan,

Are you using the IOEXPANDEREVM and the corresponding user's guide?

A "VCC not set" error code seems like TCA9535 does not have power. Can we confirm this by measuring VCC with a multi-meter?

Regards,

Tyler

0 shahajahan m 7 months ago

Prodigy 50 points

Hello Tyler Townsend,

Yes, I am using the corresponding user's guide (I/O Expander EVM User's Guide, Rev. A).
I am getting 3.2 V on VCC.

0 Tyler Townsend 7 months ago in reply to shahajahan m

TI__Guru 60958 points

Hi Shahajahan,

Can you confirm the following jumper connections?

Regards,

Tyler

0 shahajahan m 7 months ago in reply to shahajahan m

Prodigy 50 points

Hello Tyler Townsend ,

Yes I am following the jumper connection and kindly find attached image for your reference

0 Tyler Townsend 7 months ago in reply to shahajahan m

TI__Guru 60958 points

Hi Shahajahan,

The VCC = 3.2 should be okay. I think the MSP430 board is to give 3.3V to the IOEXPANDEREVM. The MSP launch board has changed since the first revision. What does your command prompt error screen look like?

Regards,

Tyler

0 shahajahan m 7 months ago in reply to Tyler Townsend

Prodigy 50 points

Hello Tyler Townsend ,

Pl find the command prompt error screen attached below

0 Tyler Townsend 7 months ago in reply to shahajahan m

TI__Guru 60958 points

Hi Shahajahan,

This is the command prompt screen I got:

Can you confirm that the jumper shorts were connected before powering on the MSP board with your computer?

Can we confirm that the MSP430 is being flashed without the IO-EXPANDER-EVM attached?

Regards,

Tyler

0 shahajahan m 7 months ago in reply to Tyler Townsend

Prodigy 50 points

Hello Tyler Townsend ,

Yes, the jumper shorts were connected before powering on the MSP board with our computer.

Yes, the MSP430 was connected with and without the IO-Expander EVM, but I am still facing the same issue.

0 Jack Guan 7 months ago in reply to shahajahan m

TI__Guru 54801 points

Hello,

Tyler is currently out of office and responses will be delayed. Thanks!

Regards,

Jack

0 Tyler Townsend 6 months ago in reply to shahajahan m

TI__Guru 60958 points

Hi Shahajahan,

I am ordering a MSP430G2ET EVM from ti.com to see if the EVM differences have an impact on the bootloader.

I was able to get it to work with an older version of the MSP430EVM, so let me try it with your version.

This may take a few days to arrive, probably Thursday.

Regards,

Tyler

0 shahajahan m 6 months ago in reply to Tyler Townsend

Prodigy 50 points

Hello Tyler Townsend ,

Thanks for the information.

0 Tyler Townsend 6 months ago in reply to shahajahan m

TI__Guru 60958 points

Hi Shahajahan,

You're welcome. I am in the process of ordering the updated version of the MSP430EVM to see if it still works with the IOEXPANDEREVM.

Regards,

Tyler

0 Tyler Townsend 6 months ago in reply to Tyler Townsend

TI__Guru 60958 points

Hi Shahajahan,

I tried the updated EVM on the MSP430 and got the following result - same as you:

IT seems that the newer revised MSP430 board does not work with the original IOEXPANDEREVM. I would need to check on this.

Regards,

Tyler

0 shahajahan m 6 months ago in reply to Tyler Townsend

Prodigy 50 points

Hello Tyler Townsend,

Thanks for the update!

0 Tyler Townsend 6 months ago in reply to shahajahan m

TI__Guru 60958 points

You're welcome Shahajahan,

I have made a note to have this updated.

Regards,

Tyler

0 shahajahan m 6 months ago in reply to Tyler Townsend

Prodigy 50 points

Hi Tyler Townsend,

Any update...!

0 Tyler Townsend 6 months ago in reply to shahajahan m

TI__Guru 60958 points

Hi Shahajahan,

This is a longer term fix and would require some more digging.

My recommendation would be to use an MSPM0 and the corresponding SDK's to program the TCA9535 on the IOEXPANDEREVM. For now, the GUI looks broken due to the changes made on the MSP430 EVM update.

Regards,

Tyler

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TCA9535: VCC not set error during flash process — I/O Expander User Guide (Chapter 5.3, Step 8 & 9)