The data acquisition board with SD memory card. The board provides 10 analog to digital channels from which data can be collected and stored to the SD card.
Data Acquisition: Accelerometer
Following the desire to more carefully characterize the behavior of the race vehicles, a data acquisition system was created which allows acceleration information to be collected and stored on a small SD card. This system seems superior to other possible systems because it provides an adequate sample rate, and sufficient data channels, while costing very little and not requiring an onboard computer (which would be very risky to the computer, given the intended operating conditions and environment).
The data acquisition board with SD memory card. The board provides 10 analog to digital channels from which data can be collected and stored to the SD card.
The three axis accelerometers. These units can provide readings over different ranges varying from a maximum of 1.5g to a maximum of 6g. The range is controlled by sending high or low signals to specific ports on the devices. The output is in the form of a voltage from 0V to 3.3V, with 0V representing full negative acceleration, 3.3V representing full positive acceleration, and 1.67V representing approximately zero acceleration.
A 3.3V voltage regulator along with hold-up capacitors is required so that the entire system can be powered by a single 6V source.
The system was first prototyped using a breadboard.
The data acquisition board and power source were incorporated, and the system was successfully tested.
The final device was then constructed using a soldered perforated circuit board. Note that only 3 channels on the data aquisition board are being used, leaving 7 additional ports open. This would allow for an additional 2 accelerometers to be attached to the system using all three axes, while still leaving one port available. Also note that additional connections are available on the voltage regulator board to support the possibility of expanding the system.
I welcome your questions, comments, or concerns.