Posted by Jim Morris
on Sat Oct 24 14:50:02 -0700 2009
In playing with my new Rovio I decided that my Old MS Sidewinder 3D
Pro Joystick would be an excellent way to control it, as it has the
twist which can rotate the Rovio, and the joystick up/left/down/right
can move the Rovio in those directions while still facing forward.
The problem is that the joystick has a game port connector, and my
Linux workstation does not have a game-port. After doing the obligatory
Googling I found
this Exactly what I
needed, except this was for Windows not Linux. Thinking I would have
to modify the code I contacted Grendel who graciously sent me the
source code for the project, however it turns out the code he wrote
was so good it works as is on Linux, I just needed to modprobe
sidewinder and it worked.
The project is based on a great little hackers device called a
Teensy a relatively cheap
general purpose programmable USB dev board. It has lots of
sample code showing it being a keyboard or mouse or serial port
etc. It is programmed in C using the avr-gcc toolchain. This is like a
Basic Stamp with USB, something I needed years ago but couldn't
find. Now I have one I forgot what I needed it for many years ago, but
it is in my arsenal now.
The only thing I needed to do, as I was on Ubuntu Hardy (8.04 LTS) and
not 8.10 or newer, was to build the avr-gcc toolchain myself. The one
included with Hardy did not recognize the atmel mmcu atmega32u4 type,
which is relatively new. This process is made much easier with a
script you can get from this
thread,
Note you need to register with the forum to see the download
links. The file you want is
build-avr-gcc-4.3.3-libc-1.6.7-insight6.8-arch25-fix.zip. Make sure you
read the first post of the thread and make sure you have all the
dependencies installed first according to the pre-reqs.txt file in the
download. (Especially the libmpfr-dev which I missed initially).
Anyway I prototyped the circuit using the photos provided in Grendels
post, and plugged it into a Windows XP system and it worked, then I
plugged it into my Linux box and dmesg told me it recognized the
joystick device..
[926661.299475] input,hidraw8: USB HID v1.11 Joystick [Detlef <Grendel> Mueller Microsoft SideWinder 3D Pro (USB)] on usb-0000:00:1d.7-4.3
I then downloaded jstest which is a simple joystick test program, and
all the degrees of freedom were recognized.
I wanted to make the proto more robust so I designed a PCB layout
using
ExpressPCB's
free PCB design and schematic tool (Windows based but runs fine under
Wine on Linux). These guys will make 3 off 3.8" x 2.5" PCBs
MiniBoard for
around $50, which is a get price if you can't make your own. However I
decided that for this one off project I'd just do a PCB prototype
instead, so I sent the PCB layout to Grendel as thanks for all his
hard work, in case he ever wants to go into production for this great
little project.
I got a
Schmartboard
board (around $5 from Fry's) and a Rt Angle female pcb mount 15 pin
DSub connector (.99c), and soldered the components and jumper
wires. The DSUB needed coaxing onto the board as I guess the pin
spacing is not the standard 0.01", however Shmartboard does have a
board
especially for dsub connectors, Fry's did not stock it though. I like
these Schmartboards, they are cheap and well built, through hole, and
you can even do surface mount if you have to. They are a lot better
quality than what you can get from Radio shack!
As a side note, as I am getting older and it has been 10 years since I
did any pcb soldering I found that my eyesight has deteriorated to the
point that I needed a magnifying lamp to do this work, and that my hand
is no longer as steady as it was, and that my old trusty Weller 35W
pro soldering iron was too hot and unwieldy, and I was making solder
bridges everywhere and melting the wire and connectors. (That did not
used to happen when I was younger ;) So I splashed out and got a nice
new
Hakko 936 soldering station,
with the 907 iron and a very fine soldering
tip and some
very fine solder. This made this go a lot smoother, although finding
the right temperature to use was hit and miss.
The last component was putting the finished product into a box. None
of the Radioshack boxes I had lying around would fit, so remembering
that I had great fun building an Acrylic box for my PC (which I
eventually ditched for a Silenced case), I made a little acrylic box
for the converter. A trip to Tap Plastics to get the adhesive was all
that was needed as I still had some Acrylic scraps laying around.
Anyway that was my project for this week. Next up writing the code to
control the Rovio with my Sidewinder 3D Pro. What Language to use??
Ruby, C++/Qt, Java, maybe learn a new one like Groovy? Hmmm what a
Dilemma.
Posted in
Linux,Embedded,Robotics
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Tags
joystick,usb,soldering
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Posted by Jim Morris
on Wed Oct 21 01:32:16 -0700 2009
Around 10 years ago I was playing with some home robotics, built a
simple robot, with some sensors and an on-board Linux-based PC. The
purpose was to experiment with Robot AI, a continuation of my PhD
thesis I started on some 30 years ago, but did not complete.
The robot had a camera, a digital compass, a sonar scanner and a short
range IR range detector, plus some bump detectors. I could control
it over a wifi connection, that was a Orinoco PCMCIA board plugged
into the PC104, 586 based Linux PC that was on-board. All powered by
several batteries.
I ran out of time and interest and energy and shelved the project. 10
Years later I stumbled upon a relatively cheap camera, wifi based
robot called a
Rovio
made by Wowwee, its basically a toy, but a cool one. The Rovio has
much better manouverability than my feeble attempt, and it has a
camera and is controlled over Wifi by some well documented HTTP
calls.
I bought one of these gizmos to play with, and to "use" as a remote
security camera to check on the dogs when I am not home. It fired up
my Robot hobby enthusiasm, and as I have a lot of time on my hands
these days I dug out all my old stuff, which I had mostly forgotten,
and dusted off the old PC104 embedded system and tried to get it up
and running again. I'm not sure what I'll use it for but it was
pretty expensive back in the day, so I'll find some use for
it. Maybe I'll stick it on the Rovio to give it some more computing
power.
Anyway things have changed a lot since then, a PC104 is ISA based, and
this board had no USB ports, but I did have a PCMCIA slot, which was
5v 16 bit only. This posed a problem as all PCMCIA cards today are
Cardbus 3.3v and usually 32 bit. The only wifi card I had that was
5v was the old Lucent Orinoco 802.11b card. But my AP these days is
a WPA/WPA2 based 802.11b/g.
The first fun thing was to get wpa_supplicant running on this old
thing, if possible. I mentioned no USB because one workaround was to
use a newer wifi card, I also wanted to use some flash drives. But
this turns out to be impossible as no ISA/PC104 USB cards were ever
built (according to an extensive Google search).
The board has 32Mb of RAM, and that was fully loaded, it also ran
WhiteDwarf Linux out of a
32Mb disk-on-a-chip board that plugs into the IDE socket. The old
version of WDLINUX I had definitely would not run the newer Hermes
Linux drivers and wpa_supplicant. I found that Whitedwarf is still
in business and have a newer version of wdlinux2.2. This is a
Slackware based Dist, that fits in under 32Mb of Ram and Disk. But I
want to run Ruby on this thing, and probably Java, so I needed some
more room which meant swap space, and swap and flash drives don't go
well together, so I dug out a 4Gb Seagate Microdrive I bought at
Frys a few years back, which would do really nicely. However getting
it to work reliably turned out to be tricky. I grabbed the latest
version of wdlinux, and did some digging to find it seems to be
based on Slackware 8.1, which is important as you need more packages
to make it useful than wdlinux has, so installing from Slackware
makes things easier. They have an ISO so I installed the ISO in a
Vmware Workstation, so I could compile a new kernel and compile any
application on my workstation, and then tried to install it also on
the 4Gb microdrive. This worked eventually but it turns out the
microdrive likes to go to sleep every few seconds, (I guess to save
power when it is plugged into a camera or whatnot). This caused
Linux to get upset (the kernel version is 2.4.29). I saw a lot of
errors saying "no drq after write", this was caused by it going to
sleep, as I found if I did
> dd if=/dev/hda of=/dev/null`
in a separate terminal, it kept it awake. The long term workaround
was to execute
> hdparm -B255 /dev/hda
as soon as possible after boot, this turns off the power saving
mode. I put it in /etc/rc.d/rc.S which is the first thing to get
executed on startup. This error is more than annoying it corrupted
the disk more than once.
I ordered a compact flash to ide44 adapter and short 44pin f-f cable
so I could plug the microdrive into the ide connector on the board.
So now I had wdlinux 2.2 installed on a 4Gb microdrive on the PC104
board. Luckily 2.2 came with PCMCIA and associated tools already
built into the kernel, unfortunately the module for my particular
PCMCIA adapter board was not built, so I built a new kernel with
the relevant driver built as a module, and was able to get the
PCMCIA system up, plugging in the Orinoco card loaded the
orinoco_cs driver which would work fine if I was still using
WEP. After much Googling I found that the Orinoco which is a
Hermes-I based card, would apparently work with wpa_supplicant if
you upgraded the firmware and used a Linux driver released by Agere
(who have since been acquired and their web site dismantled)
Luckily I found the source online somewhere (Google for
wl_lkm_718_release.tar.gz), and built it. The driver is called
wlags49 and comes in a Hermes-I and Hermes-II flavors and for
pccarc and pci, also the firmware is downloaded and can be either
station or ap modes. After browsing through the source code they
provided (which BTW only works on 2.4.x kernels) I figured out how
to build it properly and also build the version of wpa_supplicant
and Hermes driver that came with it. (I saw that some people have
provided patches to make the code compile under 2.6.x kernels, but
that didn't help me too much).
Initially the driver didn't seem to work too well, iwlist eth1
scanning did not seem to return anything, and wpa_supplicant also
barfed when it tried to scan for AP's. A bit more digging and reading
the sparse docs, looked like I needed to do some configuration of the
module when it was loaded, rather than allow wpa_supplicant to do all
the configuration. They provide a way to configure the Agere based
chips with a /etc/agere/iwconfig-eth1 file. I set the SSID, the
download_firmware and the debugging flags, and it seemed to fix
everything. The wpa_supplicant.conf file was pretty sparse as it was
a really old version of wpa_supplicant they were using, but it was
enough to finally get a connection via WPA to my AP. Note WPA2 is not
supported.
Along the way I was looking for alternatives, like using a newer
PCMCIA card, I had a 3.3v newer card, but that wouldn't plug in to
the 5v adapter, and I couldn't find a 5v to 3.3 v adapter on the
market, which is odd as it is one chip to do it. I also couldn't
find many 5v wireless cards, although it looked like I could still
buy a Linksys WPC11 card so long as it was v1, v2 or v3, the new
ones are v4 and appear to be 3.3v only.
So things learned...
- There are no USB boards for ISA (or PC104) based PCs
- New PCMCIA cards are 3.3v and won't work on older PCMCIA adapters
(or Laptops)
- There are no converters that allow you to run a newer 3.3v PCMCIA
card in a 5v slot
- Orinoco cards can be made to work with WPA, but require newer
firmware and the Agere drivers.
- working with old H/W is a pain, but embedded boards such as PC104
are still using old technology, although PC104+ does have a PCI bus
which allows newer boards to be used
- Using a compact card microdrive to run Linux off of is possible but
you need to disable the power management in the drive
Now I finally have my old PC104 board running again with its wireless
card and talking WPA, I have to figure out what to do with it :)
My next project is to build a USB adapter for my old Microsoft
Sidewinder 3D Pro joystick, so I can use it on Linux to control my
Rovio. This has already been mostly
done but for
Windows. I am going to modify it to talk a serial protocol so I can
plug it into my Linux workstation.
Posted in
Linux,Embedded
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Tags
linux,pc104,wpa_supplicant,microdrive
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