Port devel/arduino serial port problems [SOLVED]

Arthur Chance freebsd at qeng-ho.org
Thu Mar 14 14:59:17 UTC 2013

On 03/14/13 13:08, Warren Block wrote:
> On Thu, 14 Mar 2013, Polytropon wrote:
>> On Thu, 14 Mar 2013 08:48:22 +0000, Arthur Chance wrote:
>>> On 03/13/13 21:56, Arthur Chance wrote:
>>>> I'm trying to get devel/arduino working.[snip]
>>> I shouldn't work 13 hour days. Now I've had some sleep, I've spotted
>>> what I missed last night. The underlying code from comms/rxtx is trying
>>> to create a lock file in /var/spool/lock and that is only writeable by
>>> user uucp and group dialer. Given that I have absolutely no serial
>>> devices (or ports) on this box apart from the Arduino when it's plugged
>>> in, can anyone see any problems with making the lock directory world
>>> writeable?
>> Simply add your user (or the account the program is running
>> under) to the "dialer" group. This has been a common method
>> to allow users to access dialing programs (which were reserved
>> for root use without this group addition).
> This is also mentioned when the Arduino port is installed:
> To allow serial port locking, add your user to the dialer group:
>      pw usermod myuser -G dialer

Warren and Polytropon, thanks. I realised that this morning and added 
myself to dialer. I'd originally thought the requirement for dialler 
group was simply to access /dev/cuaU0 and wrote a devd.conf file to set 
that as mode 666. It was only after catching up with my sleep I thought 
of lock files.

However, my point was a little more general than just fixing this 
specific access problem - many desktop machines these days don't have 
serial lines or any need for dialer programs, and adding yet another 
group to an ever increasing list just so that I can talk to an Arduino 
seems a little redundant. (As does using /var/spool/lock - isn't that 
what /dev/cuaU0.lock is for?)

For anyone else thinking of playing with Arduinos on FreeBSD, this bug


in avrdude bit me (on a 9.1-RELEASE-p1 amd64 machine, talking to an 
Arduino Uno R3). The second patch (patch-arduino.c) fixed the problem, 
but it's a shame it's not included in the port 14 months after it was 

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