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How to use Multiwii com ports in Puppy 528?

Posted: Wed 15 Aug 2012, 11:38
by bill516
Hi all,

My problem is I cant see the com ports in the Multwii conf programme running under puppy 528.005.

For those of you that dont know Multiwii started out as a piece of software for flying multi rotor copters using Arduino boards Wii motion plus and Nunchucks as sensors, its got a bit bigger now. You can read all about it at http://www.multiwii.com/.

I can flash the multiwii programme to the arduino no problem but when I want to configure the sensors and things you have to use the Multiwii conf programme. I can do it all ok with windows but Linux is giving me grief, maybe because I'm not that clued up about Linux.

I have two types of Arduino pro mini and a mega 2560. The pro mini works ok using an FTDI cable and shows up in the dev/usb/tty0 or 1 but the mega 2560 has an onboard usb port and shows up as dev/usb/ttyACM0. I have been stumbling around trying things but I'm now at a loss. Checking my groups I get root, tty and lpadmin, I have chmod the ttyACMO and USB to give rwx for everybody (I'm the only user anyway) and thats as far as I have got.

So does anybody have an idea of what I need to do, to be able to see the comports in the MUltiwii conf.

Posted: Wed 15 Aug 2012, 12:36
by bill516
Sorted. I came across an article online about symbolic link comm ports.

Typed in ln -s /dev/ttyACM0 /dev ttyS8 and it linked the ACM0 to S8. Rebooted and the link was still thre.

Posted: Wed 15 Aug 2012, 12:41
by Flash
Thanks. That looks like a pretty ambitious project. Keep us posted, will you?

Posted: Wed 15 Aug 2012, 14:38
by bill516
Not sorted, I switched off then switched on and the link was still there but it didn't work. I rm'd the link re-booted re-typed the link and the MWii conf found the com port. Off and on again MWii conf couldnt find the com port. I think I might need a UDEV rule but I haven't got a clue how to write one. Looking at all the examples on the web just makes my head spin.

Posted: Wed 15 Aug 2012, 20:44
by Karl Godt
bill516 wrote:Not sorted, I switched off then switched on and the link was still there but it didn't work. I rm'd the link re-booted re-typed the link and the MWii conf found the com port. Off and on again MWii conf couldnt find the com port. I think I might need a UDEV rule but I haven't got a clue how to write one. Looking at all the examples on the web just makes my head spin.
First you need the name of the correct driver .
But udev rules can also be created to only change permissions of files ie /dev/nodes .

Check dmesg OR /tmp/bootkernel.log OR /var/log messages.

Linking /dev/ACM0 /dev/ttyS8 sounds difficult to me since most MOBO nowerdays maximum have one or two serial ports (/dev/ttyS0 and /dev/ttyS1) .

/dev/ACM0 in my Puppy is

/dev/input/ttyACM0

Code: Select all

ls -l /dev/input/ttyACM0
crw-rw-rw- 1 root root 166, 0 30. Aug 2002 /dev/input/ttyACM0
and creating it manually in /dev/ directory would be

Code: Select all

mknod /dev/ttyACM0 c 166 0
so it does not become a dead link.

Posted: Thu 16 Aug 2012, 15:39
by bill516
I came across this site

http://www.joakimlinde.se/microcontroll ... r/udev.php

which does exactly what I'm trying to do only the udev doesnt seem to work. I didnt put the Olimex AVR programmer in the udev as I dont have one just the line referring to the Arduino. If I type in the ln -s /dev/ttyACM0 /dev/ttyS5 or any other number above that I can see the linked port in the MW conf untill I reboot then its gone.

Posted: Sat 18 Aug 2012, 12:57
by bill516
Well that udev from the link I posted before seems to be working, but I dont know what I did to get it to do that. The only thing I have done is to place commas after each id part and place the ln -s command in the startup folder with a link to the file on the desktop. Whether this is a right and proper way to do things I dont know but it is doing what I need.