Arduino Shield - Stepper Driver and Digital Caliper Reader ver.3

This is my 3rd full revision of a board I am making for another project. I thought I should post the schematic/layout incase anyone else finds it useful. I am getting faster at this layout stuff. The first was so painful but I am starting to get the strategy down.

The board uses an H bridge to drive a small stepper motor. The power for the stepper is fed of the Vin pin of the arduino. So to run this you will need a 9-12v power supply feeding into the Arduino barrel jack. I have made capacity for two calipers (To measure X and Y simultaneously).

Design is based on the schematic at http://arduino.cc/en/Reference/StepperBipolarCircuit and the Nerd kit DRO tutorial. http://www.nerdkits.com/videos/digital_calipers_dro/

Check out those sites for backround reading and code.

Check back here later for build photos and my code.

Check back here much later to see the circuit in a useful application.

https://docs.google.com/file/d/0B8_hXvCtBTMMUXVFQWN4RkVTQkE/edit

The Engineering Commons Podcast

Chris Gammell of 'the amp hour' podcast has another podcast called 'the engineering commons podcast' available at: http://theengineeringcommons.com/

The show is not focused on the electronics industry but engineering as a discipline in general.

CS50 - Introduction to computer science atStanford

While I was cruising youtube for tutorials on programming I stumbled across some videos for an introductory computer science class at Stanford University. It turned out that the entire course is available online for free.

The Course is stanfords flagship unt for their faculty of computer sciences. And, because of the high status of the course and importance to Stanford as a marketing tool, you can see that they have put a lot of effort into the course (they have their own merch).

Course is available at CS50.net
https://www.cs50.net/

The lecturers are really entertaining I watched all 24 one and a half hour lectures in a few weeks. Although, I still havent got through the tutorials :D

I will be sure to [ost my solutions when/if I do them.

Rolling motor mono cycle is a certain death-trap

If the builder doesn't already have brain damage his invention should soon correct that.

Adafruit GPS shield

I finished building the Adafruit GPS shield. I did a quick test whilst I commuted back to my flat. The visualisation generator I used is at every trail here:

http://www.everytrail.com/view_trip.php?trip_id=1927731


http://www.gpsvisualizer.com/ is another site that does the same thing.

What I dont like about the module is that you have to take out the SD card to load the data into the computer. It would be great if the data could be accessed throught the serial port. I have started writing some code that allows you to manipulate files on the SD card with some basic menus over serial. However, I am having trouble erasing files. If you have any tips, please let me know.


I also want to add some triggering options to the GPS module. I want to do this to A) reduce power consumption B) reduce data density.

The plan is:
A mode switch allow you to select. 1.trigger mode (push button/external trigger ie camera) 2. Normal mode, sampling at the normal rate. 3. Interval timing timing is set by a potentiometer that allows for logarithmic interval timing. The idea here is to save power where possible.

Work Safety a lo Chileno

Note: Harness at base of column in the left of the photo.

Here are some guys working at about 7 -10m above ground. I am pretty sure they use those temporary columns to climb up there. Leter there where 4 men on that same beam. Safety standards in Chile are nowhere near what they are in Australia but this is pretty bad by Bolivian standards.

3D Printable Compact Camera Mount for Bike (Moved)

I printed a camera mount for my bike so I can record my rides/ record confrontations with crazy taxi drivers.

It is available at thingiverse: http://www.thingiverse.com/thing:37328


This is a handlebar mount for a compact camera for a bicycle. It uses a 6 x 25mm bolt for the camera and a 3 x 30mm bolt and nut to clamp the handlebars. 

Video here:
youtube.com/watch?v=5LYhufnWy6E&feature=youtu.be

Instructions

Print it! (I reccomend using the raft, the latest model had some curvature on the bottom surface.)

buy:
- 6 x 25mm bolt
- 3 x 30m and nut
- rubber washer

- Fit the M3 nut into the hole on the end. I used a heat gun to soften the plastic and then jammed it in. This way it keeps in tightly.

- Thread the M6 nut throught the block. Place rubber pad on top (this helps to dampen the vibration)

- Thread your camera onto the screw. (Note: the first camera I used was very cheap and had plastic threads which shreaded instantly. ONLY USE CAMERAS WITH METALIC THREADS!!.

- *IMPORTANT: slid the hand strap over the handlebars before clipping on the camera (just in case.)

- Snap the mount on the handlebars. It should stay where it is without the tightening nut.

- Place screw in tightening nut.

Enjoy!