DCA1000EVM: Issues using mmwaveStudio with custom IWR1843 PCB - no RS232 connection

Tillman Zumstein

Part Number: DCA1000EVM
Other Parts Discussed in Thread: IWR1843, IWR1843BOOST, UNIFLASH

Hello,

we are trying to use mmWave Studio with a custom PCB with the IWR1843 SoC. The issue I am facing is that RS232 connection can not be established ("Error: Connection failed: Calling_ConnectTarget returned 3"). I have read similar posts on this forum but could not find a solution for this issue. I have also followed the hints from the DCA1000 debugging guide with no success.

The custom PCB has the required high density connector to connect to the DCA1000, identical to the IWR1843BOOST EVM. All required connections to IWR1843 as described in the hardware design checklist are present. RS232 RX/TX lines are not connected on the high density connector, the same as on the IWR1843BOOST.
The RX/TX lines (Ball N4 and N5) and GND from IWR1843 are connected to an (external) USB-UART bridge ( Silabs CP2102) which connects to the PC.
Flashing of the IWR1843 using Uniflash works fine using this setup, therefor I assume there are no connection issues. The COM port is also accessible using a serial terminal.
SOP0 and SOP1 are connected to 3.3V, SOP2 is pulled to GND.

Here are my questions:

Are there any points I missed for the hardware setup? Is the use of a USB-UART bridge instead of the onboard debugger on the IWR1843BOOST a problem?
As I understand it the RS232 connection is used to flash the firmware to the device, is that correct?
Is it possible to create an image out of masterss and radarss firmware files and flash them using Uniflash instead of from within mmwave Studio?
Are there any other things I could try?

Thanks a lot in advance,

Tillman Zumstein

over 2 years ago

0 E. Shareef over 2 years ago

TI__Genius 15800 points

Hello Tillman,

We are looking into your query and a team member will respond to you in the next 24 hours.

Thanks,

-Shareef

0 E. Shareef over 2 years ago in reply to E. Shareef

TI__Genius 15800 points

Would it be possible for you to share a picture of your connection?

I also want to see the ports showing up under device manager on your PC. If you could share a picture of this as well, I think it'll be helpful.

Thanks,

-Shareef

0 Tillman Zumstein over 2 years ago in reply to E. Shareef

Prodigy 10 points

Hello Ehtesham,

thanks for your reply. Here's a picture of the physical connection (I can not share the PCB unfortunately):

And the connections in device manager:

Regards,

Tillman

0 E. Shareef over 2 years ago in reply to Tillman Zumstein

TI__Genius 15800 points

Are you using COM5 for the RS232 connection?

+1 CHETHAN KUMAR Y.B. over 2 years ago in reply to E. Shareef

TI__Mastermind 25835 points

Hello Tillman,

Potentially external USB-UART bridge could be problem, as all the USB to UART devices doesn't behave in the same manner. We haven't used Silabs CP2102 USB to UART for our device communication.

You could refer to below EVM which has CP2105 Silabs chips for connecting to UART. The enhanced COM port is the application/user UART that must be connected to RS232 signals. If the COM ports are connected to other UART ports we have seen issues for connecting to RS232 ports.

https://www.ti.com/tool/IWR6843AOPEVM

https://www.ti.com/tool/IWR6843ISK

Another issue could be device may not be in the right SOP mode:

Please disconnect while entering into different SOP Modes (i.e. Flashing or Functional modes), And connect after SOP assertion and NRESET release.

Note that UART/ JTAG I/Os are not fail safe hence it should not be driven when VIO supplies are not present. This may mess up the SOP mode detection logic.

USB supply could be powering the Pull up resistors on the RS232 line which is different from that of mmWave sensor VIO, leading to incorrect power up (Boot up) scenario.

Please see some of below thread on this topic.

https://e2e.ti.com/support/sensors-group/sensors/f/sensors-forum/1037079/iwr6843isk-ods-custom-board-can-t-enter-flash-mode/3834858?tisearch=e2e-sitesearch&keymatch=sop%20detection#3834858

https://e2e.ti.com/support/sensors-group/sensors/f/sensors-forum/963367/iwr6843-mmwave-studio-is-frozen-during-writing-mss-fw/3559419?tisearch=e2e-sitesearch&keymatch=sop%25252520detection#3559419

Thanks and regards,

CHETHAN KUMAR Y.B.

0 Tillman Zumstein over 2 years ago in reply to CHETHAN KUMAR Y.B.

Prodigy 10 points

Thanks a lot for your reply! Tomorrow I will make some modifications to the PCB to ensure correct SOP mode at all times and to bypass a multiplexer that the RX/TX lines currently go over. I will update with results.

Regards!

0 CHETHAN KUMAR Y.B. over 2 years ago in reply to Tillman Zumstein

TI__Mastermind 25835 points

Hello Tillman,

Thank you, If possible use CP2105 Silabs USB to UART converter with enhanced comport, we had seen issues with standard com port connection. There are compatibility issues with Uniflash and Visualizer tools w.r.t to UART protocol communication.

Thanks and regards,

CHETHAN KUMAR Y.B.

0 Tillman Zumstein over 2 years ago in reply to CHETHAN KUMAR Y.B.

Prodigy 10 points

Thanks a lot for your support, it looks like bypassing the multiplexer did the trick, all connections seem to work fine now. If there are further issues we will try to use a UART bridge with enhanced COM port as per your suggestion.

Regards,

Tillman

0 CHETHAN KUMAR Y.B. over 2 years ago in reply to Tillman Zumstein

TI__Mastermind 25835 points

Hello Tillman,

Thanks for sharing this info. Glad to hear connection issue is resolved.

Thanks and regards,

CHETHAN KUMAR Y.B.

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DCA1000EVM: Issues using mmwaveStudio with custom IWR1843 PCB - no RS232 connection