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Hello,
I am having trouble establishing serial communication from NVIDIA microcontroller(Jetson nano) and the Roboteq motor controller(FBL2360T)
The idea is to communicate motor commands from the Jetson.
RS232 logic level from motor controller: +/- 10V
Using an RS232 to TTL convertor, I am able to convert it to 3.3V logic level. (https://www.serialcomm.com/serial_rs232_converters/rs232_rs485_to_ttl_converters/rs232_to_3v_ttl_converter/rs232_to_3v_ttl.product_general_info.aspx)I have checked the wiring multiple times, set the baud rate to 115200, but there seems to be only junk values transmitting.
Individually troubleshooting components: Roboteq with PC works and NVIDIA with PC works as well.
There seems to be an issue when connecting NVIDIA to Roboteq controller.Any thoughts and support are highly appreciated.
Hello,
When converting RS232 to TTL you have to set the RoboteQ to use inverted serial logic. Please refer to pages 178 and 179 of the RoboteQ user manual.
Thank you for the prompt response. I did set it to inverted serial logic and I’m able to measure logic high around 3V(with a multimeter) at the end of the convertor but still getting some junk values at the end of the NVIDIA. What is the best way to check communication from the motor controller with the NVIDIA? Can I request a query like controller voltage so I get a response?
Hello,
Also is the diodes and resistor setup necessary if I am using RS232 to 3.3V TTL adapter for conversion?
I’m not familiar with the adapter you’re using. However, we use the circuit on page 179 on a regular basis. You can purchase the PCB here. This circuit would replace your adapter, and as the documentation states, the diodes are optional.
To validate the communication you can open a python terminal on the Jetson and send ASCII queries while printing the response.
Oh okay. Thank you.
Without the diodes, how would the circuit look like? Would I still need to tie the Tx pin to 5V at the controller side?
Is there a sample program which I can use? I am currently using a program which only accepts serial commands(https://github.com/JetsonHacksNano/UARTDemo)
No, removing the diodes would just leave the resistor between the Jetson Rx and the RoboteQ Tx.
We don’t have a sample program available for this but that demo script looks like a good starting point. You can just modify the write payload and read the response to print out.
Hello,
Should I set the motor controller to inverted or non-inverted RS232 mode for testing this configuration?
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