projekte fachhochschule hamburg E/I
6 beiner in völliger Dunkelheit This picture developed with absolute darkness
(at least which concerns the visible light ;-) )
it shows our 6 legged robot (already shown) illuminated exclusively with the light of the IR light emitting diodes. You'll easily notice that this picture is black-and-white. That is because the IR light is detected as white light from the camera. And because here is only reflected IR light the the picture results in black-and-white. You can also see that the IR light is reflected by different colours differently well (or bad). The blue eyes reflect the IR light e.g. very well, why they do not differ from the white background.
 
 
Extended Camera aus According to USB specification a USB device may draw 500mA current with 5V. The camera draws somewhat fewer than 100mA current. Therefore I decided to use 8 IR LEDS with 50 mA in each case. The Siemens SFH485 IR light emitting diodes I used are droping a forward voltage of 1,5 Volt. That means 3,5Volt are dropping at the used resistor. With U = R * I results for R = 3.5v / 50mA = 70 ohms. With the 75 ohms I selected, a current of 46.67 mA results. (8 * 46,67 = 373.36 < 400mA) the Siemens SFH485 have a max. forward current of 100mA, thus no problem with 50 mA.
 
 
Extended Camera an By the clear housing you can see the plug of the camera quite well. The green and the white cable are for the data, the black is ground and the red is +5Volt. The small circuit must be attached thus on black and red. Better use a switch, because the selected 1/4 Watt (250mW) resistances become already a little warm.
(P = U * I --> 3.5v * 50mA = 175 mW)