Recently I started using my linux laptop as my primary avr-usb development environment. When I upgraded the laptop to the current Ubuntu-LTS release (10.4 aka Lucid lynx) a bunch of stuff was broken including all of the wonderful udev rules provided by my linux savvy friends at dorkbotpdx.

I mean jeesh even lsusb was broken.

$ lsusb -vd "03eb:"|grep iM
cannot read device status, Operation not permitted (1)
iManufacturer           1

When I started looking at what changed and how to adjust, the web dead ended to a lot of threads like the one at http://ubuntuforums.org/showthread.php?t=1360412 ; where two people declared that having to escalate privileges to root in order to talk to a user device was “normal”. Even when the developer said it wasn’t normal the ubuntu folk redeclared it normal (apparently after Bush you just have to repeat something blatantly stupid for it to be true). As an administrator the last thing you want is everything and its dog requiring root privileges.

Hanging around the #ubuntu channel was a lot like having people repeat the searches on the web that provided me with the same dead ends that I joined the channel trying to resolve.

Cherchez la femme (look at the squeeze)

This was getting stupid. All I wanted to do was to have devices that I could plug in and program and then communicate with them using ruby or perl or some other haphazzardly thrown together scripts without having to be root. Then I realized once again that ubuntu is really focused on making the users life easier and that this leads to a lot of non technical help. So I asked my friends what the nick name was for the Debian release that was the basis for the Ubuntu release nick named “Lucid” and then re did all of my dead ended web queries replacing “Ubuntu Lucid” with “Debian Squeeze”.

The results were heavy on the technical detail and light on social skills.

More importantly I quickly found the solution that I needed in the middle of this link (http://git.zerfleddert.de/cgi-bin/gitweb.cgi/usb-driver?a=blob_plain&f=README&hb=HEAD) what I was missing was the difference between the new and the old udev rules.

“If you are running a newer version of udev (as in Debian Squeeze and
Ubuntu 9.10), you need to adapt the rules-file to the new udev-version:
sed -i -e ‘s/TEMPNODE/tempnode/’ -e ‘s/SYSFS/ATTRS/g’ -e ‘s/BUS/SUBSYSTEMS/’ \
/etc/udev/rules.d/xusbdfwu.rules”

One line of sed was all I needed and it had taken me a week of asking about lucid when i should have been asking about squeeze. With this I also was able to find the changes to the lay out of the /dev and /proc trees and the new tools to monitor udev and diagnose issues.

All-Your-Atmel-Belong to Us

I really just wanted to change the permissions so I could use my devices. Adding the following udev rule to your system will do just that.  You will also need to restart the udev service. Both of these will require you to be root.

# cat >/etc/udev/rules.d/98-all-your-atmel-belong-to-us.rules<<EOF
#------------------------/etc/udev/rules.d/98-all-your-atmel-belong-to-us.rules
#
# Make atmel devices (dfu, LUFA, obdev) accessible in userland
# 
ACTION=="add", SUBSYSTEMS=="usb", ATTRS{idVendor}=="03eb", MODE="0666"
EOF
# service udev restart

To actually own all my atmel I could have also added ‘ ,USER=”don” ‘ after the mode part but I just wanted to talk my Atmel usb-avr devices and the open source firmware I was developing. And the above rule made things “just work”.

$ lsusb -vd "03eb:"|grep iM
iManufacturer           1 mycompany.com
$

This rule fixed all of my LUFA based devices including the my open source arduino programmer as well as the dfu programmer.used to code them. Hopefully it will be a while before I have to go through this again.

• They force you to carry redundant dependencies.
• They do not allow you to fetch and compile the source files in a transparent way.
• They do not give you clean access to the patches they use to make things work.
• They haven’t had a current version of avr-gcc in over 4 years.
• They just dont get it.

Today, I am working on a cross platform USB device which I hope to interface with ruby, python, and perl using libusb. The ruby bindings for libusb are for 1.0.xx which actually almost works on OSX nowadays. A quick sampling of using ruby-usb on osx, like most things embedded in apple land, is a trip more or less to hell. (see: http://www.jedi.be/blog/2009/11/11/ruby-usb-libusb/ http://www.ruby-forum.com/topic/192042) . Since most of my ruby is gem installed I just need a working version of libusb so I go to the darwin ports recommended above. Looking at the “raw” port file I see that there are really only two patches and so I go find them. They aren’t exposed for reasons that seem pretty stupid to me,  but I did find them at. http://libusb.darwinports.com/dports/devel/libusb/files/patch-libusb__io.c and  http://libusb.darwinports.com/dports/devel/libusb/files/patch-libusb__os__darwin_usb.c

When I downloaded the source file and went to wget the patches it got even more screwey.

wget http://libusb.darwinports.com/dports/devel/libusb/files/patch-libusb__io.c
--2010-07-06 00:28:13--  http://libusb.darwinports.com/dports/devel/libusb/files/patch-libusb__io.c
Resolving libusb.darwinports.com... 208.185.168.32
Connecting to libusb.darwinports.com|208.185.168.32|:80... connected.
HTTP request sent, awaiting response... 403 Forbidden
2010-07-06 00:28:13 ERROR 403: Forbidden.

I didn’t want to deal with it so I just saved the links in my browser and patched the source files manually. After that a

./configure; make && make install && make clean

let me do the normal ruby thing.

gem install ruby-usb

Just like on all the other operating systems.

What you will get.

• A servo and a geared motor with paper feed.
• A motor driver board.
• Misc parts.

What to bring:

• A dorkboard, teensy or other arduino capable board.
• A soldering iron.
• Some basic tools (esp wire cutters, x-acto knife)
• superglue
• A hot glue gun.
• foamcore or cardboard.
• $35 or a copy of your rsvp / paypal reciept.

Where:

PNCA — 1432 NW Johnson St, Room 205

When:
Sunday May 30nd from 1 to 5pm

How do I rsvp?

• Via paypal — Select the session on the TDI Products page:
  (http://tempusdictum.com/tdproducts.html)

You can also rsvp via email and bring cash but it is easier to plan and track the money if you use paypal.

An introduction to physical computing for artists and musicians.

What:

This workshop is an opportunity for 15 to 25 people to spend a week working on the fundamentals of integrating micro-controllers into the arts. At the end of the week participants should be able to build and program their own Arduino compatible micro-controller system and use it to interact with the physical world using motors servos lights relays and switches.

The workshop will be structured with a hands on approach. The theory being that we learn best by doing. The first two days will be devoted to building and programming the base platform and using it to control various devices. The remaining 3 days will be a lab devoted to incorporating the new tools into actual pieces. The cost of the course is $105 and includes the materials listed below as well as 5 days of hands on instruction.

What you will get.

• A Benito usb to serial programmer
• A Dorkboard! (an Arduino clone) Kit
• An introduction to the Arduino and microcontrollers in an artists setting
• A servo and a geared motor with paper feed.
• A motor driver board.
• Misc parts.
• Help when you need it
• To know that what you built worked at least once
• Ideas

What to bring:

• A laptop (there will be some (not many) loaner systems available)
• A soldering iron (20-30W Pencil type)
• A standard usb cable (A->B)
• Some basic tools (esp wire cutters, x-acto knife)
• superglue
• A hot glue gun.
• foamcore or cardboard.
• A copy of your rsvp / paypal reciept.
• Ideas.

When:

June 7th through June 11th from 1-5pm.

Where:

Object Space Gallery:

1818 1/2 E Sprague, Spokane WA

How do I rsvp?

• Via paypal — go to  TDI Products page: (http://tempusdictum.com/tdproducts.html)

– or –

• If you dont paypal contact me ddelmardavis , at the gmail.com directly to make other payment arrangments.

• Modularization.
• Simplicity.
• Stepwise refinement.

Tools

DS1306

Best code example is at .http://www.nearfuturelaboratory.com/2006/12/14/arduino-and-ds1306-real-time-clock/

only problem with sample code is that it only works in the full sp mode and the diagram on the page shows the other mode. (need a32khz crystal)

To Do:

Exchange for Tuesday

Give walt

• 32khz crystals
• proto boards
• Bare lcd (maybe a temp/lcd controller board)
• Laptop and EPC (load with ubuntu 9.10).
• 4 dorkboards.

To develope.

• Software modules for timer and lcd.
• Better lcd/button controller
• led meter boards.

das blinkin

With a lot of my projects I have done my prototyping with Paul Stoffregon’s Teensy series of boards before moving them onto their own codebases. On those occasions where the “prototype was all I needed” I would compile the code using the teensyduino and then manually load the .hex file onto the target. As I am looking at using the arduino for more projects I decided to take a look at how paul interacts with the Arduino IDE and see if I could load code directly onto my chips.

boards.txt

The arduino allows for different chips and configurations through the boards.txt and the programmers.txt files. Each configuration usually will also have a “core” which maps the pins and handles the particulars of that chip. When you run paul’s teensyduino installer it adds several entrys to the boards.txt file including the entry below.

teensy_ser.name=Teensy 1.0 (USB Serial)
teensy_ser.upload.protocol=halfkay
teensy_ser.upload.maximum_size=15872
teensy_ser.upload.speed=38400
teensy_ser.upload.disable_flushing=true
teensy_ser.upload.avrdude_wrapper=teensy_reboot
teensy_ser.build.mcu=at90usb162
teensy_ser.build.f_cpu=16000000L
teensy_ser.build.core=teensy_serial
teensy_ser.build.post_compile_script=teensy_post_compile

teensy_ser.name=Teensy 1.0 (USB Serial)
teensy_ser.upload.protocol=halfkay
teensy_ser.upload.maximum_size=15872
teensy_ser.upload.speed=38400
teensy_ser.upload.disable_flushing=true
teensy_ser.upload.avrdude_wrapper=teensy_reboot
teensy_ser.build.mcu=at90usb162
teensy_ser.build.f_cpu=16000000L
teensy_ser.build.core=teensy_serial
...

#############################################################
fouryou.name = atMega32U4
fouryou.upload.protocol=atmega32u4
fouryou.upload.maximum_size=32256
fouryou.upload.speed=38400
fouryou.upload.disable_flushing=true
fouryou.upload.avrdude_wrapper=dfume
fouryou.build.mcu=atmega32u4
fouryou.build.f_cpu=16000000L
fouryou.build.core=teensy_serial
#############################################################
tooyou.name = atMega32u2
tooyou.upload.protocol=atmega32u2
tooyou.upload.maximum_size=32256
tooyou.upload.speed=38400
tooyou.upload.disable_flushing=true
tooyou.upload.avrdude_wrapper=dfume
tooyou.build.mcu=at90usb162
tooyou.build.f_cpu=16000000L
tooyou.build.core=teensy_serial

#############################################################

fouryou.name = atMega32U4
fouryou.upload.protocol=atmega32u4
fouryou.upload.maximum_size=32256
fouryou.upload.speed=38400
fouryou.upload.disable_flushing=true
fouryou.upload.avrdude_wrapper=dfume
fouryou.build.mcu=atmega32u4
fouryou.build.f_cpu=16000000L
fouryou.build.core=teensy_serial

#############################################################

tooyou.name = atMega32u2
tooyou.upload.protocol=atmega32u2
tooyou.upload.maximum_size=32256
tooyou.upload.speed=38400
tooyou.upload.disable_flushing=true
tooyou.upload.avrdude_wrapper=dfume
tooyou.build.mcu=at90usb162
tooyou.build.f_cpu=16000000L
tooyou.build.core=teensy_serial

I started with a blank script that just printed the arguments passed to the wrapper and then called it by restarting my Arduino (to reload the boards.txt) And then selecting one of the new boards and “Uploading” my code. This gave me a window to interactively work through my script. Since the avrdude_wrapper code just pretends to be an avrdude most of the script is munging the arguments passed to avrdude to get the commands to pass to dfu-programmer.

#!/usr/bin/perl
use Getopt::Std;
print @ARGV;
my %args;
my $hexfile;
my $dfu = "/usr/local/bin/dfu-programmer";
my $cpu;
my $hexfile;

getopt('pUc',\%args);
$hexfile=$args{U};
$hexfile =~ s/flash:w://;
$hexfile =~ s/:i//;
$cpu=$args{c};

print "\n[" . $hexfile . "]";
print "\n[" . $cpu . "]\n";
print "$dfu $cpu erase\n";
system "$dfu $cpu erase";
print "$dfu $cpu flash $hexfile\n";
system"$dfu $cpu flash $hexfile";
print "$dfu $cpu start\n";
system "$dfu $cpu start 1>&2";
print "\n";

There is one tricky bit. The current avr-gcc doesnt support the atmega32u2 correctly but the code for the at90usb162 is binary compatible so the build.mcu is set to the at90usb162. But then dfu-programmer supports the correct chip and wont find the device so we use the fact that the upload.protocol argument is passed directlyalong using the -c argument and everything works fine.

So now we just use the hwb and reset buttons to get the system into dfu mode and upload our code directly from the arduino. Its not as slick as the teensy in “auto” mode but it works.

The testbox is an LCD/Dorkboard based arduino clone with two buttons and a pair of potentiometers. The switches, power and 4 io pins are made avaliable via screw terminals on the ouside of the testbox.


#include
/*--------------------------------------------------------------
pulse generator for test box

lcd.setCursor(0,1);
if (s1) {
lcd.print("ON ");
} else {
lcd.print("OFF");
}
lcd.setCursor(6,1);
lcd.print("# ");
lcd.setCursor(8,1);
lcd.print(pulsecount);
}


Midi Monster Button Locations.	Benito 7g Switch Positions.
Benito 2010 Switch Locations	Benito Without Buttons.

All of the code on the Benito and MidiMonster devices is open source and references an open source library called the Lightweight Usb For Avr (lufa). Getting the code compiled and onto the device requires a few other open source tools.

AVR-GCC

The most current and stable release of the toochain for the AVR has untill recently been maintained by Eric Wedddington and released as WinAvr (http://sourceforge.net/projects/winavr/) Winaver integrates nicely into atmels avr studio http://www.atmel.com/dyn/Products/tools_card.asp?tool_id=2725 and I reccomend that you get both if you are running windows. Each Winavr Release is closely followed by objective developments CrossPack for avr http://www.obdev.at/products/crosspack/index.html and a script for building the current toolchain on linux which is hosted by AvrFreaks at present there is also a debian package that was put out last month http://www.avrfreaks.net/index.php?name=PNphpBB2&file=viewtopic&t=90172

HWB? DFU?

Most Atmel “atmega” devices have a pin dedicated to determining weather or not the device goes into the bootloader depending on the devices flag settings. This pin is labled HWB (for hardware boot) on most of  the datasheets. The usb avr family has this mode set up by default. When you hold the hwb pin low and reset the device it goes into the bootloader. On these devices the built in bootloader uses a usb device class called the Device Firmware Uploader (DFU). Atmel provides a tool called flip for programming DFU devices on  windows and linux. There is an open source programmer called dfu-programmer http://dfu-programmer.sourceforge.net/

That other guys stuff.

Those of you who have worked with the teensy boards from paul stoffregon will notice some subtle differences. Paul wrote his own (closed source) bootloader rather than use the bootloader tha comes installed on the chips. Then he uses a hardware trick similar to the auto reset hack to make a single button manipulate both the reset and the hwb pins to put his boards into the bootloader. I didnt feel that either the two button arrangement or the builtin bootloaders were broken so I like most people working with these chips dont fix them.

Using the dfu-programmer

All of the programs in Dean Cameras Lightweight Usb for Avr have a “dfu” target. Once you have the target into the DFU mode you can simply

$make dfu

This will cause the dfu-programmer to erase the flash reprogramm it with a new hex file and restart the chip. You can also do this manually with the following commands

$dfu-programmer atmega32u2 erase
$dfu-programmer atmega32u2 flash mycode.hex
$dfu-programmer atmega32u2 start

This will cause the dfu-programmer to erase the flash reprogramm it with a new hex file and restart the chip.