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SYSTEM OVERVIEW

I saw the AOSI electronic tilt sensors on the ’Net a long time ago. But to justify buying some sensors and having them shipped to me from the U.S., I knew I would need a good reason to use them. Suffice it to say, the purchase was put on the long finger. Driving sensors and showing numbers on a simple display is all well and good, but without graphics to give a visual indication of the angle, it would be pretty boring.

Things started to come together when a collection of low-cost Epson mobile phone LCDs came my way, although I did have to ferret around for a while until I found the controller in these screens and the pinout. Everything fell in place when the Philips ARM Design Contest 2005 came along. I now had a small LPC2138 ARM microcontroller (given out as a sample for the contest), which had the right amount of onboard RAM and plenty of flash memory for graphics and sound.

Although this unit hasn’t been packaged into an end product, all of the basic functions are included. It can display angular information numerically, provide a visual indication of the current position in the form of a bubble vial, and generate audio. There is no reason why you can’t add a number of other features in the form of PWM outputs and control RC servos.