Recently I was doing a bit of research for my main project as well as that of the Lampbotics project and found something interesting. As noted in one of my previous blog post it was mentioned that there is a fair amount of Jitter in the movements of the servos. It was suggested that one of the reasons for this was that the RPi was working too hard to achieve this. However doing a bit of work in controlling servos, on their own with nothing else, I found that this jitter still existed. It turns out that this is a documented occurrence.
This is a link to the Python RPi.GPIO library page. On it is a description on the operation of the code and says it is not suitable for time critical operation, much like that of the PWM signals. From this I figure the external board is the best approach. The Adafruit Servo Hat seems like the best option over all other available servo controller boards. The board itself can be attached easily to the RPi2 GPIO connections making for a slim design, has its own power supply and can hold up to 16 servo connections future proofing the designs.
In terms of my next sprint I have taken on the LED control module using OpenCV to detect the colour and then display it on the LED’s. The LED’s that will be controlled are the NEOPIXLE LED’s using an Arduino NANO with the FASTLed Library for ease of use.
Luke, 4th Blog Entry