Paper scan unscrewing and straightening

If you (like me) like taking quick pictures (writing stuff down is not my hobby) with your cellphone for later reference you might also regret the bad quality that one most often meets when taking a quick snapshot or memo of a memo, letter or a whole document.

Some times you simply need a proper scanned document, yet have no flatbed scanner at hand. Or later realize this quick memo has to be redistributed or touched up and look good. Can you do it without a flatbed scanner?

Yes, your mobile camera will do! There are tools that unscrew and straighten your document photo or scan. These tools where built for digitizing books and the necessary restoring of paper scans;

• Scan Tailor
  Scan Tailor has a rather rudementary GUI and may suit most needs. Especially when working with attended restorations: you can see and tweak the scanned pages.
  
  
• Unpaper
  Unpaper as an Linux commandline application this might not be very userfriendly, but it saves the day ..every day.
  

Also, if once feels inclined these are easily integrated or ported to Android application. Did i mention i love Android?

Installing VLC 1.0 on Ubuntu 9.04 (Jaunty)

By default the jaunty repository maintained by Canonical doesn't include the latest VLC release. Bummer! Yet very easy to overcome.

UPDATE 20091010: Found a better method:
http://ubuntumanual.org/posts/195/install-all-new-vlc-1-0-in-ubuntu-jaunty-intrepid-hardy
Never mind the rambling below.

To install VLC and other affected applications enable the "Third Party Software" repositories:

• start Synaptec Package Manager, find it at System > Administration
• open Repository Settings, via Settings > Repository
• open the tab "Third-Party Software" and check the two default items;

http://archive.canonical.com/ubuntu jaunty partner
http://archive.canonical.com/ubuntu jaunty partner (Source Code)

• Apply your settings, and choose Reload. Done!

You may now search for the latest version of your favorite non-Canonical-maintained application, and it should still show up.

Thats all folks, easy as pumpkin pie. And i don't even like pumpkin pie.

Multi/Dual monitor setup with Synergy

Today my workplace was below par: my dual monitor workstation was defect and i even forgot my Acer notebook. What should i do?

All i had to work with was this pile of retired rackservers that i tend to accumulate. These wheren't up to speed, so i decided to strap them together and make the most out of it. I wanted to use these as a more powerfull (multimonitor) workstation. So i installed the latest Ubuntu on two of them.

Then i remembered learning about Synergy years ago.

Synergy lets you easily share a single mouse and keyboard between multiple computers with different operating systems, each with its own display, without special hardware. It's intended for users with multiple computers on their desk since each system uses its own monitor(s). - Synergy sourceforge website

Hearing lots of people had trouble setting getting it to work, here is a short (Ubuntu) howto. 

1. Install QuickSynergy on all systems
   Synaptec Packet Manager should work, otherwise try this method: Applications > Add/Remove, now choose "Show: All available applications", and search for QuickSynergy, check it in the list, and click Apply.
   
2. Run QuickSynergy on host
   This is the workstation that has the mouse and keyboard connected. Pick the most powerfull machine.
   Enter the IP hostname of the client in the directional box of your choice. (Moving through this edge makes your mouse spawn on said computer.)
   Click the Execute button.
   
3. Run QuickSynergy on client(s)
   Enter the IP address of the host in the Use tab.
   Click the Execute button.
   
4. Done
   Move the mouse to the edge of the host screen - it should now appear on the client screen!
   

I still prefer Compiz on Ubuntu, but this is the next best thing. Especially if you can trow hardware at the problem. Now i MacGyvered myself a decent workplace.

Expect a howto on permanent Synergy setup, so you wont have to reconnect after each reboot. Oh and Synergy works across all mayor platforms. Its terrific! Check their site.

Also, i've given up on my workstations hardware problems. The AGP card used to work fine after kicking the machine once or twice... the last fourty didn't make a difference. Except for the satisfaction.

Update 20091005: Adjusted article; i discovered that entering the clients' hostname (instead of IP) on the host (see 2nd step) is more successful.

Use the CM5 as USB2Dynamixel

Without a €60 USB2Dynamixel you'd have to control the AX12 via the CM5. Luckely it has a "TossMode" that makes it behave much like a USB2Dynamixel. This saved my day while my USB2Dynamixel is on order.

How to enable TossMode:

• Connect the CM5 to power and serial PC cable.
• Launch "Robot Terminal". (part of the Bioloid software supplied by Robotis)
  
• On the CM5, select mode "Manage" and press start.
• The robot terminal should display some text the CM5 send, and you might want to type "help". But we won't.
  In the terminal, pres "t" and hit enter. The CM5 responds with "tossmode", and you're good to go.
• Free the serial port on your PC by closing the "Robot Terminal".

You may now use the CM5 as if it is a USB2Dynamixel. For example start "Dynamixel Commander" and connect on the same COM port and BAUD. (default is COM1 and 57600kbps)

Please share your experiences!

Note that some USB2Dynamixel software (including those using the supplied API and libraries) won't work due its builtin FTDI (the USB>serial chip) driver thats pretty useless here. Only stuff that directly adresses the AX12 on a serial port will. See the AX12 manual on how to construct these raw-byte packages.

Introduction to Bioloid and the AX12

The Bioloid kit (by Robotis) exists mostly of brackets, AX12 actuators and a CM5 containing a microprocessor. For years i wanted to dab with it - yet hold it off - i was afraid the distraction might hurt my study or income.

The "comprehensive" Bioloid kit costs roughly €800 and is a bargeon considering you get 18 AX12's usually going for €50 each. Recently i got donated two AX12 with mechanical problems, and borrowed another AX12 + a CM5 to complete an assignment.

Eventually i just want a decent robotics hardware platform to program for. The feedback the AX12 has (temperature, load, torque) combined with the intelligent control it offers (variable compliance, calibration, angle limitations, accelleration and speed) give it some serious punch over the next best thing: regular servo's.

Best thing here is that the AX12 has a family (Dynamixel) so if my software works on the AX12, i can easily scale up to more powerfull actuators by Robotis. I'm waiting for the day my desktop spider transforms to a road-legal contraption or autonomous "Disney" experience.

For more on the AX12 see the crustcrawler.com website, they've have all specs listed conveniently with a nice resources overview.