So I received an unexpected tax rebate and decided to treat myself to an Arduino Starter Kit and a pack of assorted sensors. And boy, is it fun!
I’m reading schematics! I’m downloading datasheets! I’m scribbling circuit diagrams in margins! It takes me right back to my first job working on a Z80 based embedded system, interfacing with lots of TTL logic in 1985 (although in those days you couldn’t just “download” a datasheet, you had to phone up Farnell Components and ask them to send you one).
Anyway, in the picture you can stage one of my first custom project – an ultra-sonic radar! The idea is that the stepper motor will rotate the ultra-sonic distance measuring sensor thorugh a 180º arc, averaging the distance to obstacles over about 10º and using some block characters on the LCD display to show a crude graphical “map” of what is ahead.
I’ve taken a lot of the wires away so you can get a clearer view. The stepper motor is top center, screwed to a convenient ‘U’ shaped lego piece. This is attached to a set of Technics gears that give a 12:1 reduction and the ultrasonic sensor is mounted on the last gear. The blue thing hanging down is a magnet, which will trigger a micro-switch that will be placed on the green brick behind it (once it arrives from Amazon). This will allow the device to calibrate its initial position on start-up, by just rotating once until the switch is triggered.
I’ll post updates as the project moves further along.