Moving on from Slider v01, I’ve tried to improve the performance of the system and to move towards a more stable, flexible and -hopefully- reusable arduino code.
In this video you see a motorfader box on the left and another one on the right. In between is a Tablet connected to a computer, of which you see part of the screen at the bottom.
With the pen and tablet, I control the botton slider on the screen (the white slider). The top green slider represents the box on the right and the bottom one the one on the left. The size of the box in the white slider shows the difference between the pen-input and the average position of all 3 sliders together.
The electronic circuit that controls the motorfaders has not changed from v01, I mostly re-wrote the arduino code to include a PID-controller (well, just using Proportional and Derivative component), inspired by the wikipedia and this arduino.cc post.
I have added the possibility to connect the system to a Max/MSP patch, to have a third slider to interact with the system.
However, the serial communication increases duration of the program loop, and this influences the gritty and the ‘friction’ feel on the sliders as well as the stability of the whole system.
Another TODO point is to implement error detection/correction in the serial communication as now there seems to be some noise from this.
It also seems that the whole system ‘wiggles’ to the high slider positions when MAXMSP is attached. So far I have no clue why. ( I have added some smoothing/averaging on the analog reading in the arduino, and it seems to help a little).