Archive for May 2009
Update: I’ve written a huge post on how to buy sliders/faders/slide potentiometers
As copiously stated, I have no formal training in electronics, and I’ve reached a mature enough age that I can no longer accept an electronic component as a black box, so when I come across a device and can figure out how to use it without being able to locate instructions, i feel like it’s only right to make a drawing of it and try to explain my hypothesis for how it works.
With that being said, here’s my best guess at how the 10k slide potentiometers (sliders / slide pot) works:
The obvious control at the top sets the resistance. The voltage in (V+) and ground (V-) pins run inline with each other, and the resistance value is read from the pin adjacent to the voltage in pin. I’m using an Arduino to read the value, and in my case, i actually needed an additional resistor in front of the voltage in pin to limit the incoming current. When i hooked the slider up directly to the arduino, it didn’t work very well, acting way more like it was a logarithmic curve potentiometer than the linear curve pot I thought it was. About 2 minutes later, it was blistering hot. Too hot to touch, actually! So, I quickly disconnected it from the arduino and added a 10k resistor in front of the voltage in, and then it started behaving much more reasonably. The values I was getting from the 10k slider were not what I was expecting, so I’ll have to dial back on the current resistor from 10k to maybe 1k and see if that helps get the values from the slide pot more inline with my expectations.
Derek and I have been working hard on building some useful tools for beat sequencing using Rosco and Max/MSP. Poking around at Max/MSP made me realize how much I understand PureData, so I went back to PD and built a comprehensive “data-in” patch to receive the OSC messages from Rosco.