Tinkering Accelerometer + Gyroscope AKA IMU (Part 1)

Its been some time since I fiddle with anything interesting...

The amplifier chassis is fun but just couldn't drag myself to build it as it doesn't arouse any sense of achievement since it never do anything at all...

Dug out this dust covered 5DOF IMU from my hoarder's corner...

I bought this for a song while roaming mindlessly in the deep internet space sometime ago...

Doing something with this will surely beats any amplifier projects.

 
Let me introduce you to this little gem.
It is an analogue output 5DOF(Degree of Freedom) IMU (Inertia Moment Unit) board consisting of 3 axis accelerometer ADXL335 chip by  Analog Devices and  2 axis gyroscope chip IDG500 by InvenSense.

This will save me from soldering 2 multi-legged SMT chip which are about the size of my nostril hair. 

SPECIFICATIONS

Accelerometer

AnalogDevices 

ADXL335

Axis	X, Y, Z
Measuring Range	±3.6g
Non-Linearity	±0.3%
Vcc	3.3V
Sensitivity at Xout, Yout, Zout	270~330mV/g, typically 300mV/g
Zero g Bias Level (Ratiometric) 0g Voltage at Xout, Yout 0g Voltage at Zout	1.35~1.65V, typically 1.5V 1.2~1.8V, typically 1.8V
Frequency Response Bandwidth Xout, Yout Bandwidth Zout	1600Hz 550Hz

Gyrometer

InvenSense 

IDG500

Axis	X, Y
Full-Scale Range Sensitivity	X-OUT & Y-OUT X4.5Out & Y4.5Out X-OUT & Y-OUT X4.5Out & Y4.5Out	±500°/s ±110°/s 2.0mV/°/s 9.1mV/°/s
Frequency Response	140 Hz
Zero-Rate Output Static (Bias)	Factory set 1.35V
Vcc	3.3V

IMU SHIELD

Even though it is a breakout board, This thing is still tiny my my standard! 

To save my sanity & eyesight, I drawn up a PCB as shield for Arduino.

IMU Arduino Shield

By fiddling with the jumper pin, I can choose which ever accelerometer axis Xout,Yout or Zout to A0 pin & Gyro's X-OUT, Y-OUT, Z-OUT, X4.5Out or Y4.5Out to A1 pin just

Others stuff the PCB design to do, 

1) tied up the Vcc to the Arduino ARef pin.

2) add pads & holes so that there is an option to solder or using pin plug to get to the Arduino pinouts.

Word budget is up for this article. In the part 2 of this series of article, I'll dive into reading the IMU which will involve some maths, some coding & some simple point to point wiring.

Arduino

It has been a few years since I’d started to look for a mean to start on micro controllers stuff. PIC is the recommended chips as I was told they are cheap and abondon locally.

Bought many books and spent hundreds of hours surfing the net with no fruitful progress…. These books eventually became my best cure for insomnia… It never fail to put me to sleep in 20 minutes…

Everything which I found require me to build some thing, either a programmer or hardware to actually make the micro chip work… Its too much challenge for me… so the search continue

Found this book while wondering aimlessly in my local book store a month ago.

By Massimo Banzi, co-founder of the Arduino Project. Published by Make Magazine.

The cover cough my eye.

“Arduino” has appeared with increase frequency in my google search for how-to starter packages for electronically challenged beginner like me. I didn’t dig this AVR based board as I was looking for PIC stuff. What a mistake!

This is the only book on MCU which I finish reading in one go… and awake!

I learn what Physical Computing meant, Arduino uses C language, everything is open source, the board contain the necessary hardware to operate and plugin USB.

Arduino is “ready-to-go”, no need to know about bootloading, I/O connections, I2C, USB chip, communication chip... etc etc which I couldn't care less, so that noobies like me can get our claws right into the fun part.

There is a growing community such as
http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl
Seriously fun ppl.

and their web page is packed with great stuff such as ready made codes/programs, meaning we don't have to reinvent the wheel!
http://www.arduino.cc

The potential application is only limited by your imagination! We can do useless thing with it such as teaching our flower to call for help when they get thirsty, lights off in the absent of occupant, control an autonomous robot, intelligent home system, track the sun, control an miniature UAV, feed the monkey, skin the fish.... all of which you can jump straight in as long as you know what make things tick, perfect toy for tinkerers.

Just placed an ordered a "clone" Arduido starter pack, (wanted to go for the real thing but they have the best shipping charges.) should arrive by next week, can't wait to blink some LED....