scoutingrobot

Latest update: Comm. works with MAX232 chip perfectly. But its kind of cumbersome electrical setup. A lot of capacitors.

Got a voltage close to 5V using Max232.

Should I opt for Max3232 instead since it has 3.3V supply and might give a logic level of close to 3.3V ?

Hello,

I tried serial communication with USB from Roboteq to Jetson Nano, worked perfectly.
But the same with an adapter and the circuit on Pg 179 does not work at all.

Really stuck right now. Max232 is the last resort.

oh sorry about that. Have tried flipping the diodes in either direction but the voltage level at the Rx of NVIDIA still showed 4.95V which I think is a clipped voltage as it cannot take in excess of 4.95V

Would a MAX232 chip work for communication?
I have tried it before with PC and PIC microcontroller and it has worked.

Only concern is would it bring it down to 0-3.3V logic levels.

I have attached the connection diagram below. Kindly, take a look and let me know if anything is incorrect.

Sorry, don’t have an oscilloscope.
What data can I send to see the motor controller respond?

So, should I run the code and try receiving something to check the voltage at Rx?
Currently, it is just 0V.

Sorry, in RS232 inverting mode, the voltage measured along the other side of the resistor is around 9V roughly.
The voltage is only getting dropped across the resistor and the diodes are not affecting the circuit in any form.

Hello,

I measured the voltages:

Between Roboteq, TX and GND: -9.19V
Between NVIDIA, TX and GND: -0.2V

Shouldn’t I receive 0-3.3V at this other end?

Hello,

I measured the voltages:
Roboteq, Tx and Gnd: -9.19V
NVIDIA, Tx and Gnd: -0.2V

Why am I receiving a negative voltage near the NVIDIA side?
Shouldn’t it be 0-3.3V?

Yes. It is 4.7k

Could you please help me resolve this issue?

I can still measure 9V after the diode and resistor

And the voltage drop near the diode and rx pin of the microcontroller should measure 3.3V and less?

Hello,

Should I set the motor controller to inverted or non-inverted RS232 mode for testing this configuration?

Oh okay. Thank you.

Oh okay will follow the same connections and try executing the script once. Will get back to you if I have any doubts.