It's also possible to modify the software in the unit so it can measure other things if it can be connected to a i2c-bus.
Top Thrill Dragster
Step 1: Introduction
I have been working on this project in my spare time over two years now.
I use a LIS3LV02DQ from ST-Microelectronics to measure the forces, a uALFAT from ghielectronics.com to manage the SD-card, a HCMS2915 display and a PIC16F876 to control every thing. I also use a Canon NB-4L battery ( the same model i have in one of my cameras) to power the unit.
BOM (aka what you need) :
a PCB (a gcprevue-file to download)
a piece of Plexiglas 72.3x57x8 mm to the battery compartment
a piece of Plexiglas 3 mm thick to the front window
soldering iron with a small tip 0.4mm
some mill bits
thread cutter M3
Super glue and some regular glue stick
a X-Y table from Proxxon
a bench mounted drill
a battery (I use a CANON NB-4L).
a Microchip PICkit2 programmer.
a aluminum case 1455B802BK ELFA.se
a broken camera to get a battery connector from
and some surface and hole mounted components (BOM-file below).
Step 2: Prepare the PCB.
(The new PCB layout has every thing cut out if it's ordered from a board-house and just needs to be broken apart.)
Step 3: Populate the PCB.
The trickiest part to solder was the sensor, that have all the connections on the bottom of the component (I borrowed the x-ray @ work to check that the soldering was perfect :) ).