Extra character received from UART

I’m experiencing some issues when reading from the UART.
Basically, I periodically send a start message to a raspberry using the UART connection. Once it receives the UART message, the raspberry performs some network transmissions using the cellular network, and then it sends the results through the UART connection.
Unfortunately, some of the reply messages (in this case, the raspberry is the sender) have an extra character in the middle of the string. To reduce the noise I connected the DGND pin and reduced the baudrate, but I didn’t get any improvement.

Could this behavior be due to a low voltage level? Do you have any other suggestions for possible causes of this behavior?

Hi and welcome to the forum,

To understand this, I need some more information (there will be more questions coming…).
If you do not want to post this here in the forum, then I propose that you create a case in our case system (https://stage.qoitech.com/cases)

  1. Is this with Otii 2.8.x or 3.x application software
  2. Is this with Otii Arc or Otii Ace Pro?

Best regards,


I’m using the Otii Arc and the Otii 2.8.4 software on Windows 11.

I would like to give you more detail about the problem I experienced:
The additional character on the UART channel is received sporadically. Sometimes there may be several corrupted messages received in a short interval. But, at the same time, there may be several hours without problems.
Additionally, sometimes my raspberry gave me some “undervoltage detected” warnings. This is why I suspected a voltage-related problem.

Thank you


Thank you for this information.
Could you create a case in our case system and add a recording where the undervoltage condition occur, please.
Add current, voltage and UART channels.
I also believe that there is the undervoltage condition that disturbs the system.

Best regards,