Sunday, February 26, 2012

Saturday, February 25, 2012

Art of Electronics book

Here's where I got my copy.

Open Source Lipo Charger

Very Nifty! Paul Asselin has an open source hardware design, based on the Microchip MCP73831.  You can download the schematics and Eagle files directly. He also sells a kit or completed unit.

Sony 600TVL Super HAD board camera for FPV

As recommended by Bruce, who notes "I am not sure which lens I have on this camera -- I requested a 3.6mm lens but the box says 2.8mm. I will check and update the review accordingly."


BidProduct Crimping Tools

Will any of these work for balance plugs?  Must investigate!  Many more on the page.  PS, this is the site with all the micro receivers as well.

Zephyr II launching notes

From Chris:


Launch with 3/4 throttle to full power.
Align elevons to match wing top foil contour out by the wing ends
and give 3 to 5 clicks of up.  If you align with bottom you will
stall it as soon as you launch and naturally try grab for elevator
up.This will also cause the roll out during the tip stall, its not
an issue with lateral balance , its you stalling it by too much up
input and no airspeed.
Once you get it flying and trimmed power on then do a few passes
under good power and chop the throttle to see if she rises or drops
once power is removed.  If it does either than your thrust angle
is off ,and will need to adjustment.
Launching it with no power and holding it back by the prop opening
is just asking for finger slicing issues.


Friday, February 24, 2012

X468 Flame Gear Camera Mt For GoPro

Atlanta Hobby is carrying this nice looking underbody multicopter GoPro mount.  250 grams, roll and tilt.  Uses HS-55 sized servos. $110.

Monday, February 20, 2012

Stencils for Cloverleaf Antennas

chatch15117 @ RCGroups has a link with stencils for constructing cloverleaf antennas.  Each frequency has its own stencil.

Monday, February 6, 2012

XBee thinks it's a Mouse on Windows...

Here's a problem I had when connecting the XBee to Windows:

  • Plugged in xtremebee USB.
  • Kept getting behavior as if the right mouse button was being pressed.
  • APM could not connect over XBee link.
  • Opening the "Devices and Printers" control panel showed that Windows 7 was thinking the xbee was a mouse.


I looked at various settings to see if there was a "this is not a mouse" button.  I didn't change anything, but it seems to have fixed things.

John Church figured out the problem and the cure:

  • It happens when the APM side is powered up before the PC side.
  • When the USB is attached, Windows sees data coming in over the serial link.
  • Windows comes to the (stupid) conclusion "this must be a mouse!"
  • Fix: power up the PC side USB XBee before powering up the APM.

Wednesday, February 1, 2012

Arduino class notes, class 3

Varieties of I/O devices





Pull-up Resistors





Labs

  • circ-07 buttons.
  • circ-11 relays.
  • circ-05 shift register, multiple LEDs.

Bidirectional Motor Control with Relays
  • one pair of relays (3,4) control motion
  • one pair of relays (1,2) control direction
  • smarts courtesy of JWZ





Interfacing to Computer

  • coming up next week