I'm using the Arduino Starter Kit so I have a Uno R3 and going through the examples I'm trying to read temperature data from my controller in Arduino Studio.

In essence my problem can be reduced down to

void setup() {

void loop() {

Which I'd expect to keep printing "stuff" on the serial monitor.

(In practice I'm running this exact code but all the temperature-reading going on feels irrelevant to my problem, I'm simply mentioning it because I can observe that mye LEDs light up when the temperature rises so I know the code is uploaded and running on the Duo).

I'm not seeing any errors in the studio console, and if I connect using gtkterm or screen I can see data being sent so the problem seems to be isolated to the AndroidStudio serial monitor itself.

I'm running Ubuntu 14.04 and I've connected via USB on /dev/ttyACM3.

I tried running

stty -F /dev/ttyACM3 cs8 9600 ignbrk -brkint -icrnl -imaxbel -opost -onlcr -isig -icanon -iexten -echo -echoe -echok -echoctl -echoke noflsh -ixon -crtscts

as suggested here and I also tried with baud 115200, taking care to also change the value in my setup function.

I also ran

chmod a+rw /dev/ttyACM3

But I'm still not seeing any errors or output. How do I proceed to debug this issue?

Running ls -l /dev/ttyACM* gives

crw-rw---- 1 root dialout 166, 0 feb. 20 14:22 /dev/ttyACM0

crw-rw---- 1 root dialout 166, 1 feb. 20 14:22 /dev/ttyACM1

crw-rw---- 1 root dialout 166, 2 feb. 20 14:22 /dev/ttyACM2

crw-rw-rw- 1 root dialout 166, 3 feb. 20 14:30 /dev/ttyACM3

  • 1
    Test GtkTerm or PuTTY. – Mikael Patel Feb 20 '16 at 12:45
  • @MikaelPatel Thanks, that should help me isolate the problem at least :) – ivarni Feb 20 '16 at 12:50
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    What's the output of "ls -l /dev/ttyACM*"? – Avamander Feb 20 '16 at 13:29
  • 2
    Try putting the string "stuff" into double quotes instead of single quotes. – Avamander Feb 20 '16 at 13:47
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    I'm voting to close this old unresolved question because the asker reports in comments that "I don't own either the arduino itself or the computer I was using any more" which means that it will be impossible to ever conclusively resolve this issue. – Chris Stratton Aug 7 '17 at 20:03

By default, on a linux system without specific udev binding rules to rename the device into something non standard, the FTDI driver should map the usb to serial port on /dev/ttyUSB* and not to /dev/ttbACM*. I suspect that you were just looking in the wrong place. I think it defaults to /dev/ttyUSB* for any usb to serial dongle:

usb-serial.c:   usb_serial_tty_driver->name = "ttyUSB";
  • In order to make sure you're looking in the correct device file run "sudo dmesg -C" priot to plugging in the Arduino, and subsequently just 'sudo dmesg" to see where teh usb to serial converter was attached. You should see a message much like this: ch341-uart converter now attached to ttyUSB0 where the ch341-uart is replaced by what your arduino has (most likely FT232'ish) – louigi600 Apr 27 '17 at 14:18
  • This is probably not applicable. The post claims to be using an Uno R3, which does not have an FTDI but rather has a custom USB serial implementation in an ATmega16u2 which will map as a ttyACM device not a ttyUSB one - that only happen on boards using other USB serial solutions, like older Arduinos and assorted clones and compatibles. – Chris Stratton Aug 7 '17 at 20:00
  • Ok but still doing the dmesg thing will tell you which is the correct device that linux is assigning to the arduino .... it won't show ch340 or FT* .... but it will still report what's the assigned character special file in /dev . – louigi600 Aug 17 '17 at 8:22

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