Correct pin connection for UART to receive Serial on RX

Support
1

I am not sure what I am doing wrong, but I have opened OTII and asked it to read from Serial, but it isn’t showing any data.
is there something special I need to do?

2

Hello

You should connect the TX pin of your device to the RX pin on the front of Otii Arc. Then in Project Settings under the log tab you should enable UART and set the correct baudrate.

Data is split by newline or carriage return, so make sure you have some of them in your output.

3

Do i need to press play or do anything else?
I am asking because I connected a TX from my device to the RX, but nothing was displaying. (Verified Baud rate, etc)

But, when I connected the same device to a USB to Serial converter, I could read the data from the device using Putty serial.

Thoughts?

4

Ah, yes.

You need to start a recording as well. It’s general for all our data collection, we only collect data if a recording is running. Project -> New Recording, or the + sign in the side bar.

5

When I connect the TX pin from the Nucleo-L053R8 board to the RX pin on the otii, and the ground (GND) is connected to the digital ground (DGND) of the otii, and enable UART by setting the baud rate to 9600, and press the UART log and press the record button, nothing is printed on the console of otii. Am I doing anything wrong?

When I connect the controller using USB and open Tera Term, I am able to read the data.

what will be the wrong part in my case?

6

When I connect the TX pin from the Nucleo-L053R8 board to the RX pin on the otii, and the ground (GND) is connected to the digital ground (DGND) of the otii, and enable UART by setting the baud rate to 9600, and press the UART log and press the record button, nothing is printed on the console of otii. Am I doing anything wrong?

When I connect the controller using USB and open Tera Term, I am able to read the data.

what will be the wrong part in my case?

7

Hi and welcome to the forum,

Have you set the digital voltage level to the right level for your Nucleo-L053R8 board?
Do you only enable UART channel? You need to have an analog channel enabled also, to get the UART data.

Another test you can perform, to check that nothing is broken, is to connect UART RX to UART TX and also Sense+ channel and then enable Sense+ and UART channel and turn on a recording.
Then input test into TX-data window and see that the data is visible in RX log and that the voltage changes on Sense+.

Best regards,
Björn

8

Otti1
Otti1929×660 64.6 KB

Otti2
Otti21261×695 174 KB

Thank you for your response. I don’t understand why enabling the analog channel is necessary to receive UART data. Do I simply enable it in the software, or do I need to modify the hardware connections?

I’ve set the baud rate to 9600 as required by my application, but I’m not receiving any output in the console. I’ve forwarded images of the OTii application and my hardware connections.

Thanks,
John

9

Hi John,

Isn’t digital voltage level 3.3V for the Nucleo-L053R8?
You need to have an analog channel enabled in the Otii3 UI, to get UART data in the UART log.
You do not need to have any real analog data, but you need to have the channel enabled.

Not sure what you are showing in the picture with Otii3 UI and Main current channel.
Have you connected the Nucleo-L053R8 power to the Arc main output?
Then Main current shows the current that the Nucleo-L053R8 draws.
Do an offset calibration before, if you haven’t done this in a while (Device → Calibrate or right click on the device and select Calibrate).

Have you tested connecting according to my description?

Best regards,
Björn