MMA7260 is 3-axes accelerometer and measure the accelerations in X Y and Z axis with range +-1.5 g to 6 g.(software selectable sensitivity). Adding the ARM7 with USB interface and the serial flash memory open up possibilities to implement a lot of interesting projects with this small board. The original idea for this board was inspired by the movie Minority Report where Tom Cruise instead of mouse used his hands to interface with the computers from the future. Searching the net for more info on this subject we found similar project here. It looks not bad but the acceleromaters used are 2 axis and the whole project was done too complex. Our goal was to make so small PCB which to be able to attach to your finger and with mini USB connector to be able to connect to any PC running Windows and to use it as 3d mouse i.e. moving your finger left - right-up-down to move your mouse cursor and if you move your finger toward the screen to make the mouse "click" action.
This of course doesn't limit the applications of this board other cool application to be made is for instance car performance logger: as we have the acceleration and have microcontroller which can measure the time we can easily compute the velocity V = A * t, then the distance S = V * t and as the accelerometer is 3-axis we can calculate at what distance in 3D space the object moves. If we know your car mass we can calculate the force applied F = m * A and from this we can calculate your real car power P = V * A, so having this little board inside your car and knowing your car mass you can have calculated in real time your car characteristics: Acceleration (0-100 kmh / 0-60mph), Braking distance, Horsepower, etc etc and remember these are the actual measurements on your car not catalogue data. Yet another application is to measure the vibrations and shock on objects, for instance put one such device with battery power supply inside your parcel before send it by FedEx and then the recipient dump the info logged - what time it took, what velocity parcel had, did they drop it on the floor (i.e. at what max shock it was exposed), what time it was actually moved and with what speed, how many time it stayed rest i.e. it didn't moved and you can evaluate the different couriers efficiency this way?
- MMA7260Q 3-axis accelerometer from Freescale Semiconductor Inc. measure +-1.5 g - 6 g
- AT91SAM7S64 ARM7 microcontroller
- AT45DB011 1Mbit serial flash for data logging
- mini USB connector
- PCB: FR-4, 1.5 mm (0,062"), green soldermask, white silkscreen component print
- Dimensions: 40x20 mm (1.57 x 0.78")