This is the first line detection unit. This device should recognize the optical track, which is adhered on the floor. This version works with five ultra bright white LED's. They illuminate the floor directly beneath five light dependant resistors (LDR's). The microcontroler reads out the different values of the LDR's via ADC's (analogue digital converters). Then, the controller produces a PWM for steering, which should keep the wheelchair on the track.

Although the device works, it does not work precise enough. I will have to improve it.

A close up of the LED's and the LDR's. The gray plastic things are sawn out of vinyl.

Bottom view of the device.

Back to the diary

Please note, that the content on this webpage is licensed under a Creative Commons Attribution 2.0 License. Please respect the copyright of other webpages' content, which are linked from this webpage.