Communicate with Arduino Due using 9bit serial

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TNiroshan

Joined Jan 30, 2017
3
I want to use two RS232 ic's (Max232) to transfer data to a Arduino Due and then from the Arduino it communicate with the PC (com port) using usb. This work with Arduino mega 2560, but I wont work with Arduino Due, because I want more powerful microcontroller than Arduino mega 2560 (Arduino Due having 32-bit ARM core microcontroller). If I say simply I want to communicate the outputs of the two RS232 ic's which having 9bit's with Arduino Due. Arduino Due having 8bit serial communication bits.
Is it possible to use 74HC4067 multiplexer for this communication between RS232 and the Arduino Due.
Please suggest me a method to do this. Thank you.
 

shteii01

Joined Feb 19, 2010
4,644
Due has 4 RS232 ports.
Serial 0: Pin 0 and Pin 1, these are connected to ATmega16U2 which you are using to connect to PC using USB.
Serial 1: Pin 19 and Pin 18, this one is free, you can connect it to RS232 chip.
Serial 2: Pin 17 and Pin 16, this one is free, you can connect it to RS232 chip.
Serial 3: Pin 15 and Pin 14, this one is free, you can connect it to RS232 chip.

One final note. Due is 3.3 volt system. Most RS232 chips are 5 volt systems. It would be best if you look for RS232 chip that uses 3.3 volt system. If you can not find one, then 5 volt chip will likely work. Or you can use level translator chip between Due and RS232 chip to translate 5 volt signals from RS232 into 3.3 volt signals that Due uses.
 

shteii01

Joined Feb 19, 2010
4,644
I'm using icl3232 ic it communicate bitween arduino and the rs232.
http://www.intersil.com/content/dam/Intersil/documents/icl3/icl3221-22-23-32-41-43.pdf
That should work. It has two RS232 ports, you can use this one chip to talk to two devices. You can connect Serial 1 from Due to the Port 1, and Serial 2 to Port 2.

You would then have:
Serial 0 for Due to talk to PC over USB.
Serial 1 for Due to talk to Device 1 over RS232.
Serial 2 for Due to talk to Device 2 over RS232.
 
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