Apr 112009
 

I’ve been exploring various types of gearmotors. DC motors by themselves spin too fast and have low torque. Gearmotors are motors with a gearbox that slows down the high speed of the motor and produces higher torque. Most gearmotors are pretty expensive though. I want a really cheap, almost throw-away, source of gearmotors. It turns out cheap servos can be made into continuous rotation gearmotors.

Modding servos for continuous rotation is not a new hack. You can find many examples of it. You can even buy a nice continuous servo made by Parallax. But I wanted a micro servo version. I’ve been getting cheap servo motors from Hobby City, and they have several super-tiny servos for less than $4. The ones I use here are the Hextronic HXT500 available for $3.49 each.

Here’s how to modify one of those servos to make it into a tiny little gearmotor.
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 Posted by at 12:10 am
May 312006
 

ThingM‘s own Mike Kuniavsky was featured on BoingBoing today. Woot!

Mike spent some time getting a Gyration Air Mouse to work on Mac OS X as a gestural input device. The Gyration stuff is interesting because it’s based upon a two-axis gyroscope. It’s not accelerometer-based like some of the old game console controllers (or like the Sudden Motion Sensor in the new Mac laptops)

I got a few of those mice as well to experiment with, thinking it would be a cheap way to acquire a gyro, since dual-axis gyros are pretty pricey.

Except when you take it apart, it turns out the gyro is huge:

The gyroscope is the large silver cube. This is no MEMS device like all the other gyros, but some honking steampunk-like device that measures Coriolis effect using electromagnets.

I’m considering talking to Gyration about getting a few OEM samples of their gyro for non-mousing applications. Or maybe just get the datasheet from them and canabilize some Air Mouses.

 Posted by at 5:33 pm
Mar 012006
 

I recently obtained a ReadyNAS NV by Infrant, on the recommendation of my friend Ben Franco, who’s done much research on large disk arrays. The ReadyNAS pretty much rules. I think my long-standing storage woes may finally be over.

readynas status screen

It’s a dedicated Network Attached Storage (NAS) box that does RAID-0, RAID-1, RAID-5, or a proprietary combo of the three called “X-RAID”. X-RAID allows you to start with one disk, move to two, then three, then four, all without rebuilding the RAID or changing RAID levels.

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 Posted by at 12:38 pm
Mar 122004
 

I read this on Slashdot, so it must be true:

T-Mobile will allow their phones to be unlocked after about three months of service. Just send email to simunlock@t-mobile.com with your name, phone number and IMEI number and they’ll hook you up.link

 Posted by at 8:15 pm
Feb 172004
 

I’m beginning the process of switching to T-Mobile (from Cingular), because “Tmo” has very cheap all-you-can-eat data plans: from free to $19.99, depending on the level of studliness you want.

I’ll be using a Sony-Ericsson P900.

There are apparently 4 different “Internet plans”:

  • $0.00 – “free/unlimited internet”, aka “basic WAP”
    “just ports 80 (web), 25 (smtp), 110 (pop3), 143 (imap). ”
    all others blocked (and some reports say only port 80 is allowed as of late 2003)
    access to the t-zone portal sites. NATed?
    uses APN ‘wap.voicestream.com’
  • $4.99 – “unlimited t-zones”, also aka “basic WAP”
    same as above, but access to t-zone portal
    uses APN ‘wap.voicestream.com’
  • $9.99 – “unlimited t-zones pro”
    same as above, but access to slightly different portal
    allows one to “access corporate email” ???
    uses APN ‘wap.voicestream.com’
  • $19.99 – “T-Mobile Internet Unlimited”
    no blocked ports, non-NATed too?
    uses APN ‘internet2.voicestream.com’
    Does ‘internet2′ represent a GPRS gateway and ‘wap’ a GSM gateway?

Calling their ‘data specialists’ was pointless. Comments in t-mobile howardforums are also very confused.

Some perhaps useful info gleaned tho, in rough order of usefulness:

  • “Definitive Internet/T-Zones plans post”. It gives current (Jan 2004) and historical definitions for the various T-Mobile Internet plans. Unfortunately,
    he calls everything ‘WAP’ and thus makes no distinction between GPRS and GSM.
  • Also by the same author: “How to configure WAP on Ericsson P800/900″
  • There is a T-Mobile Wireless Data Configurator that may be useful. Once you go through the ‘wizard’, it sends a magic SMS message with configuration information that’s supposed to ‘just work’.
  • Setting up a P800 on T-Mobile: http://www.howardforums.com/showthread.php?threadid=262715
  • Free WAP allowed ports”
  • thread about free wap
  • Outgoing SMTP mail server : “myemail.t-mobile.com”
  • “Internet2/Internet3 DNS settings”:
    • West DNS – Primary: 216.155.175.40 , Alternate: 216.155.175.41
    • East DNS – Primary: 216.155.175.170, Alternate: 216.155.175.171
    • Central DNS – Primary: 216.155.175.105, Alternate: 216.155.175.106

    whatever the fuck that means, maybe ‘internet2.voicestream.com’?

  • “So for those of us who want to use the free data instead of paying $19.99, I understand the following change has to be made in our connection settings.
    • Previous with $19.99 plan: +CGDCONT=1,,”internet2.voicestream.com”
    • Now with FREE wap plan: +CGDCONT=1,,”wap.voicestream.com””

    The ‘internet2′ / ‘wap’ hosts are referred to as ‘apn’s. what is that?

  • Sony-Ericsson t68i settings with T-Mobile:
    T-Mobile Settings
    
    Configure for free WAP access:
    go to settings--->connect--->data comm
    add account GPRS
    CID=1
    preferred service=GPRS and GSM
    SMS access=GPRS
    configure APN as wap.voicestream.com
    no user id
    no password
    no IP address
    no DNS address
    
    Go to WAP Services
    enter a new profile
    configure to connect using GPRS from above
    IP address=216.155.165.050 (dots get entered automatically)
    No user ID
    no password
    data mode=conn. oriented
    security=off
    chg homepage: select a page such as http://wap.voicestream.com
    
    If you call T-Mobile customer support, they can email you a file which
    will automatically configure these settings, but you may be on hold for awhile!
    
    Configure for unlimited internet access:
    
    go to settings--->connect--->data comm
    add account GPRS 2
    CID=2
    preferred service=GPRS and GSM
    SMS access=GPRS
    configure APN as internet2.voicestream.com
    no user id
    no password
    IP address=216.155.165.050 (dots get entered automatically)
    no DNS address
    
    set Bluetooth options as follows:
    
    mode-->operation mode=on or automatic
    make discoverable or pair with your computer if you haven't done so.
    
    set your computer or handheld to use bluetooth,
    "telephone number": *99***2#
    No account name or password.
    
    You should be able to connect.
    
 Posted by at 12:45 am