The local junk shop had some old barcode scanners for $5 so I bought one thinking I could use the camera for something, like following lines.... The result is a mongrel robot made from scrounged parts that tracks a black line on white paper* How's that for a couple of days' work?

 

Features

• atmel mega8 @ 15.36Mhz (good baud rates), pulled off a teaching board and given to me by a labtech. he told me it was poked, but it's clearly not!
• 2088-pixel NEC uPD3753 ccd linear image sensor / line-scan camera
  • image output: repeated frames, single frame
• 2x orphaned sanwa servos hacked for CR
• 2x 700mAH li-ion batts
• runs megaload, Sylvain Bysonnette's serial bootloader for the avr. it's great but the PC app needs a bit of work (v. annoying popup), and the autobaud config didn't work well (on the micro) so i just set it 9600 or whatever the default was. otherwise its great! the code loads blindingly fast. my laptop doesn't have a parallel port (needed by my poor-man's isp progger), but does have a serial port so the bootloader was perfect for uploading code through the mega8's uart
• double-sided pcb made with press 'n peel
• funky red lights
• C source (not much use unless you have the exact same hardware).
• serial debugger for matlab

*I could have implented features like white-on-black and dynamic ambient light nulling, but just wanted to prove I could make a robot out of a barcode scanner, an odd hack if ever there was one.... Next time I'll use a better (faster, smaller) camera, and probably some micro servos. Perhaps then it'll be worth playing with more, maybe get a gruntier micro and put a neural net in it ...

	Navigating a perilous trail...
	The rubber shield blocks ambient light, the leds illuminate the image.
	The wide, hi-res camera view allows full PID control (I'm just using P)
	Control board under chassis with li-ion cells.
	Camera waveform. You might want to peruse the datasheet if this doesn't make much sense.