jeb365
Posts: 15
Joined: Thu Mar 15, 2012 7:37 pm

Anyone else having trouble connecting an Arduino?

Thu May 31, 2012 12:32 am

I've been trying to get my Pi and Arduino working together for some time now. Despite my best (although noob) efforts, I've had no luck getting them talking. I've followed countless guides and read all the comments and most people seem to get it up and running with no hassle what so ever. I originally posted my problem in the python section as it first arose while trying to execute a simple serial com program to control my Arduino.
http://www.raspberrypi.org/phpBB3/viewt ... =32&t=6832
As you can see I'm getting no communication through any method I try.
Help me R-Pi community. Your my only hope.

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jbeale
Posts: 3427
Joined: Tue Nov 22, 2011 11:51 pm
Contact: Website

Re: Anyone else having trouble connecting an Arduino?

Thu May 31, 2012 12:52 am

Be aware that the Arduino Uno has a significant difference with older Arduino models, in particular, the Uno has a different serial comm chip so it is no longer the tried-and-true FTDI USB-serial chip and associated driver. I don't know what the issues are with the new Atmega8U2 or 16U2 driver, but that may be related to the difficulty (or not, if someone else already has an Uno working ok with the Pi). (I don't have either a Pi or an Uno so I can't test this myself.)

from http://arduino.cc/en/Main/ArduinoBoardUno :

The Uno differs from all preceding boards in that it does not use the FTDI USB-to-serial driver chip. Instead, it features the Atmega16U2 (Atmega8U2 up to version R2) programmed as a USB-to-serial converter.
Revision 2 of the Uno board has a resistor pulling the 8U2 HWB line to ground, making it easier to put into DFU mode.
Revision 3 of the board has the following new features:

1.0 pinout: added SDA and SCL pins that are near to the AREF pin and two other new pins placed near to the RESET pin, the IOREF that allow the shields to adapt to the voltage provided from the board. In future, shields will be compatible both with the board that use the AVR, which operate with 5V and with the Arduino Due that operate with 3.3V. The second one is a not connected pin, that is reserved for future purposes.
Stronger RESET circuit.
Atmega 16U2 replace the 8U2.

jeb365
Posts: 15
Joined: Thu Mar 15, 2012 7:37 pm

Re: Anyone else having trouble connecting an Arduino?

Thu May 31, 2012 1:31 am

From what I can tell I have an R2 Uno. Can anyone else confirm this board working with a Pi? Any suggestions on another way to communicate with the Arduino over serial in a way thats safe and easy? I'm still a bit of a noob and I'd hate to write off my Pi and have to wait again. I'm not that bothered about programming with the ide (got trusty ubuntu for that), just communicating with python.

Thanks again jbeale.

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jbeale
Posts: 3427
Joined: Tue Nov 22, 2011 11:51 pm
Contact: Website

Re: Anyone else having trouble connecting an Arduino?

Thu May 31, 2012 4:21 am

The good news is that apparently the FTDI drivers can still be used for the Arduino Uno, if this posting is true: http://forums.gentoo.org/viewtopic-p-6993050.html

The bad news is that the FTDI driver may not be available on ARM v6, which is what you need for the Pi. http://www.raspberrypi.org/phpBB3/viewt ... f=5&t=5829

Depending how adventurous you are, you can also use the Pi's built-in serial port on the GPIO pin header, to connect to the Arduino serial port. But you need to do a level-translation since the Pi is 3.3V max and the Arduino is 5V (unless that also changed on the Uno?).
See also: http://www.irrational.net/2012/04/19/us ... rial-port/

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