NYC Hobby store

America’s Hobby Center 1931 has sadly left Manhattan so it is time to find a new hobby store.
Big Apple Hobbies in Queens looks like a good one.

Crash Test: Draganflyer with Sensor Payload

Optical Flow and Computer Vision

Here is a good example of optical flow

mikroElektronika PIC Microcontrollers Free Online book

mikroElectronic offers a free online book about PIC Microcontrollers. The book is very well illustrated and cleary written with good examples.
While it mostly focuses on using the PIC 16F887 microcontroller with assembly, large portions of the book are also applicable to other PIC microcontrollers. They also sell a print copy with CD for $24.

A Mazing Robot

The Pololu 3pi Robot is a line following and maze solving specialist. The 3pi uses an Atmel AVR ATmega168 processor and is Arduino compatible and has expansion boards available for adding additional features. The most interesting thing about this robot is the speed at which this robot is able to follow lines without any odometery information. The package with everything you need is available for $119.95.

Mechanism Design Software

Linkages, 4-bar mechanism, and other multi-bar mechanisms are useful for many robotic applications such as robotic grippers, payload bays, arms, legs and a variety of other robotic limbs.

The WATT Mechanism Suite from Heron Technologies provides a software solution for designing mechanisms from arbitrary motion paths.

The user interface was easy to use and I was able to produce a simple four-bar mechanism design in under an hour. WATT outputs a variety of information such as the path error and velocity in excel format and can export geometry information in DXF. While, it was not initially obvious to me when the software encountered a problem due to the mechanism jamming, the software generally produces good results for a wide variety of cases.

The list price for a single-user copy is 1575.00 Euros, however there is a 50% educational discount available for qualified organizations.

If you are on a budget you may want to consider The Geometer’s Sketchpad which is available for $39.95. The Geometer’s Sketchpad is a software program designed for use with “smart” whiteboards. The animation mode can be cleverly used to cheaply produce motion simulations for multi-bar mechanisms without having to resort to pieces of cardboard and Brass Fasteners.
The linkage library provides some good examples of what the software can do if you are persistent enough to figure out the interface. It is helpful when learning how to use the software to remember that “smart” whiteboards are lucky to have one mouse button, and that a line can be defined by two points. Once you manage to figure out the horrible user interface, The Geometer’s Sketchpad turns out to be a pretty good program for the price.

Analog Devices IMU now available with integrated Magnometer

The ADIS16365 Inertial Measurement Unit has been updated to include a magnetometer as we had previously hoped.

The new ADIS16405 now includes a 14-bit 3 axis magnetometer allowing for even more accurate inertial measurements for your aerial robotics project.

Analog Devices promises “0.05 degree rate-sensor orthogonal-alignment-accuracy” for the alignment of the gyroscopes.

The new sensor is pin compatible with previous versions so the only design updates, besides swapping out the sensor, will be software changes.

Estimated pricing for the ADIS16405 sensor is $412 for quantities of 1,000 units.

Hopefully, they have already thought of integrating a barometric pressure sensor for use as an altimeter.

Problems and Solutions

Is this problem hardware or software? or both?

The solution to trying to troubleshoot this is a Tektronix 1230 Logic Analyzer or maybe a more modern logic analyser.

PIC SPI Bus Example

Here is some example C code for connecting to a LSI/CSI LS7366 32-bit counter from a PIC 18f4550 using the C18 compiler.

LS7366.h
LS7366.c

Unfortunately, Blogger does not seem to like bit-fields.

How To: Tapping Screw Threads

Tools

Complete Pro-Grade 115-Piece Titanium Drill Bit Set – Fractional, Numbered, Lettered Bits – Metal Index Case

Tap Magic 20016A 16 Oz For Aluminum

Option 1)
Irwin Hanson 26377 117-Piece Machine Screw / Fractional / Metric Tap, Hex Die and Drill Bit Deluxe Set

Option 2)
Greenfield Industries 4-40 Unc 3fl H2 Plg. Em-ms Straight Flute Taps

Select Capacity 1/4-5/16

Use the tap chart to select the correct drill bit for the hole, or use a SCREW CHEK’R.

In the video a #43 drill bit is used to create the hole necessary to tap 4-40 threads, which most of the electronics standoffs seem to use.