Arduino RS232 Serial Communication to Laser Control Board

With a null modem connection the transmit and receive lines are cross-linked

The problem is that we don't know if that rs232 to USB cable is acting as a null modem cable. Since we do know that the null cable switches the lines, I would not change the wiring to the MAX232 for now.

BTW, if you do have to flip them, make sure that the power is off.

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I now have full communication between the arduino and the emulation program! I feel like it is a great development.

Unfortunatly there was a power outage at my university and i can only test with the laser tomorrow.

Thank you so much for your help so far guys @J-M-L @wildbill

Ok, keep us posted :wink:

Oh, my - is your project cursed? :laughing:

BTW, how is the other student using the laser controlling it.

Oh, my - is your project cursed? :laughing:

Maybe :laughing:

how is the other student using the laser controlling it.

He is using a PLC by Siemens to control the laser. The PLC control was made by a company, not by him. He just uses the system to heat treat surfaces for materials investigation

I couldn't reuse this system, because I dont have the code.
Also I want to make a system that only requires to be booted up, upload a 3D file and then I can print metal parts. This other system cannot be integrated with the motion part so easily.

@J-M-L @wildbill
Hey guys, PROBLEM SOLVED!!!!
It looks like that the crossover of TX and RX was not enough to get the communication.

I had to acquire this component:

Now I have perfect communication, I can send instructions and recieve answers from the laser.
Thank you so much for your help and the time you spent here with me. I will keep you updated and will send a video of the machine working as soon as I finish the main code.
You guys have been relentless through this and helped me a lot.
Good luck on your future projects.

great - thanks for sharing feedback
good luck with your project

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Do you have a wiring diagram for that null modem adapter?


Interesting. I am not convinced that it is necessary, but since it's now working, I suspect that you have more interesting things to get on with.

…and INVERTS the data polarity.