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Topic: Use an Arduino UNO as a USB-to-Serial converter. (Read 70913 times) previous topic - next topic

CEstudent

Hi,

First, my apologies is this has already been asked, I searched this forum but I could not find anything along these lines.

My computer does not have a serial port, and I have a device that has a serial port that I want to connect to my computer. I was wondering if it was possible, since the computer see the Arduino UNO as a serial port, to somehow plug in my serial device to my Arduino board and have the board act like a serial port?

What I was thinking is that I could take off the atmega chip and then just use the built in USB-to-Serial converter by connecting the correct pins from the serial device into the Ground, TX and RX port on my Arduino. Will this work, or am I going to break something when trying this?

The device I want to interface with is another microcontroler that uses a serial port to send data back to the PC (data acquired by the board, not for programing the board that's by USB).

Thanks,

Coding Badly


Connect a jumper from RESET to GND.  Your Uno is now a TTL-serial-to-USB converter.  TX, RX, and GND are the connections.

PeterH

What sort of serial signal do you need? If it's a device designed to plug into an external serial socket, it's probably using RS232 signaling. In that case I'd have thought your best bet was to buy a USB-to-RS232 converter - your UNO can't output RS232 without additional hardware.

PaulS

Quote
your UNO can't output RS232 without additional hardware.

It can't accept RS232 as input, either.
The art of getting good answers lies in asking good questions.

CEstudent

I am not sure what type of serial communication it is, but I know I only need a Tx, Rx and a ground from my device to my computer.

I used a jumper to connect the reset and the ground pin together as suggested and the Rx light flashed when I send the board some text from HyperTerminal, but I was not seeing any text being sent from the board to the computer... I will not have much time to works on this for a few days, so I might just break down and buy a Serial-to-USB adapter...

Thank you for the help!!

winner10920

Swap the rx and tx, since the labeled rx and tx is of the 328p not the atmega8/16u2
So put rx of the arduino to rx of the board and same with tx and it will work

PeterH


I am not sure what type of serial communication it is, but I know I only need a Tx, Rx and a ground from my device to my computer.

I used a jumper to connect the reset and the ground pin together as suggested and the Rx light flashed when I send the board some text from HyperTerminal, but I was not seeing any text being sent from the board to the computer... I will not have much time to works on this for a few days, so I might just break down and buy a Serial-to-USB adapter...

Thank you for the help!!


I'm wondering what the name CEstudent comes from. Do you understand what sort of signals your device will produce? If you connect two devices with the wrong electrical characteristics it could damage either/both of them. If you value the hardware, you should understand what you're connecting before you try it in anger.

sdinnu

http://hackaday.com/2010/10/09/using-an-arduino-or-seeeduino-for-its-ftdi-chip/

This link might seem like exactly what you are talking about!

nikhilds123

Friends I have some doubts with this. I use 3dr radio module for my Copter. The air module has serial port connected in Pixhawk flight controller and ground module has usb port connected in my Windows 10. I tried to connect them using mission planner. Both were loaded settings in the MP but not connected each other. I accidently clicked update firmware. After that the air module is not connecting with mission planner. Receiver side went cannot access. I dont know why. May be the ground module were only updated. I dont have a ftdi or any usb to UART converter. So I searched for the solution and I got arduino can be used as usb to serial converter. I connected the air module to Arduino UNO as mentioned below
Module 5v to arduino 5v
Module GND to Arduino GND
Module Tx to Arduino Tx
Module Rx to Arduino Rx
and Reset and GND in arduino are connected.
The program used is
voil setup()
{
    pinMode(0,INPUT);
    pinMode(1,OUTPUT)
}
void loop()
{

}
First time the program didnt upload because I connected the whole setup in Arduino board. I removed all the jumpers and air module from the arduino. Then the program uploaded. May be this is because while connecting to Rx and Tx the program may not upload. After uploading the program I reconnected the 3dr air module. I tested AT command as shown in the internet. Also my ground module is not connected in laptop. But the AT command is going blank when clicking ENTER. The arduino is detected in the Port(in my computer COM8). I opened the Mission planner and selected 'SiK Radio' option from 'Optional Hardware' from 'Initial Setup'. Selected COM8 port and tried to 'Load Settings'. But It is showing 'Failed to enter command mode'. Same tried in SiK radio Config software but same problem. Please any one tell me how to connect the airmodule in Mission planner or SiK radio Config using arduino as usb to serial. So I can upgrade the version to match the ground module.

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