During the last part of the week we focused on testing the encoder wheels and the RGB LEDs. We bought balloons to diffuse the light from the LEDs. The first attempt with normal “birthday party” balloons wasn’t really convincing, so I found round, white and thicker balloons that worked way better (see Perceval’s post for picture). I found that to get a nice effect we would need 8 RBG LEDs, and I measured a maximum intensity of 440mA for these. So we have to change the battery, the one I selected last week was able to provide only 1A, and it won’t be enough, knowing that the motors could require up to 600mA.
I also tested making encoder wheels with a phototransistor and a IR LED, we got the parts on Friday to test, and I checked that the method is indeed working and will be easy enough to do on many motors. The only annoying thing is that we need an analog comparator, but some are included in the STM32F302, so we don’t even need any additional part.
Next week, we’ll test Decawave modules (real-time localisation using radio waves) to get a better idea of the precision.