AWR1642BOOST: Transmission over UART without USB

Maciej Szreter

Part Number: AWR1642BOOST

Hi, I'm able to get data from AWR1642BOOST to a linux laptop by using the https://github.com/ibaiGorordo/AWR1642-Read-Data-Python- code. However, I would like to transmit the same data without USB, but directly to a standard UART, using the RX/TX pins in the J6 header.

As I can see, these pins are called RS232 but they in fact work with the standard TTL logic. When connecting a TTL-USB adapter to pins 5 and 7, I'm able to see the greeting message after powering up the board, and the configuration strings when the python app sends them. However, I can neither initialize the radar by writing to this port, nor get any radar data into it. Could someone make it clear how to work with a non-usb serial? Assume that I want to use TTL-USB adapter(s). How many I needed? A single one for duplex transmission? Or two, working with different baudrates? How to connect them?

over 6 years ago

0 Cesar over 6 years ago

TI__Guru*** 148954 points

Hi

Please see

e2e.ti.com/.../795929

Thank you
Cesar

0 Maciej Szreter over 6 years ago in reply to Cesar

Prodigy 40 points

Thank you for your answer. However, I'm still unable to get any data from the MSS_LOGGER pin. There is a remark on soldering the R26 resistor, however I can check with a meter that this pin (9 in J5) is already connected to MCU.

In the thread you point at, RS232 seems to be confused with TTL. Is MSS_LOGGER signal at the RS232 levels? (negative/positive voltage) Or TTL? (0-0.8V, above 2V - high)

Another question which is not answered there, is how to initialize the radar when not using USB? By writing to J6 TX at 115200 bps? But it also does not work for me...

Here I can see the same question:

e2e.ti.com/.../713268

0 aozer over 6 years ago

TI__Mastermind 30565 points

Hello,

The are 3.3V CMOS.

Did you populate resistors R166 and R169 to bring the RS232 pins to the header?

The device is configured via the RS232 pins on the device. The radar data is sent out via the MSS_LOGGER port.

Regards,

Adrian

0 Maciej Szreter over 6 years ago in reply to aozer

Prodigy 40 points

Hi, thanks for answering! I have a Revision A and can't find these resistors on the schematics published in one of the threads, which seem to be for Revision B. Tx works for sure, because when powering up the board, the greeting message shows up. Rx also seem to be connected to the MCU, I can verify this with an ohm-meter. The same is true for MSS_LOGGER, but I can't see any data being sent there.

0 aozer over 6 years ago in reply to Maciej Szreter

TI__Mastermind 30565 points

Hello Maciej,

For RevA it is the same resistors, R169 and R166 on J6 that will bring the RS232 pins to the J6 connector. Can you look at the assembly files and verify by sight that R26, R166 and R169 are actually populated? If you did not populate these resistors it is almost impossible that they were accidentally populated during assembly, so it is very unlikely that the signals are actually being brought to the header.

Regards,

Adrian

0 aozer over 6 years ago in reply to aozer

TI__Mastermind 30565 points

Also, you can download the design files here if you do not already have them:

www.ti.com/.../awr1642boost

Regards,

Adrian

0 Maciej Szreter over 6 years ago in reply to aozer

Prodigy 40 points

But where these resistors are situated? I have found sprr251a.zip file, and they are there on the electric schematics, but not on the one showing the placement of parts on the board. The same for the resistor for MSS_LOGGER. Thanks for the link, I'll look for appropriate files there. But I think that the pins are connected, as the meter confirms the connection to the MCU and Tx clearly emits the greeting message.

0 aozer over 6 years ago in reply to Maciej Szreter

TI__Mastermind 30565 points

You can find the locations in the assembly file:

AWR1642-BOOST_Rev-A_Assembly.pdf

Regards,

Adrian

0 aozer over 6 years ago in reply to aozer

TI__Mastermind 30565 points

We have successfully been able to send the configuration and receive the radar data using the same cable as below:

www.digikey.com/.../7064488

You will need two cables, one for the configuration port (RS232TX and RS232RX) and one for the data port (MSS_LOGGER). Baud rate should be set to 115200bps.

Regards,

Adrian

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AWR1642BOOST: Transmission over UART without USB