You will find source code for Arduino projects in this section of the site.
Hammond B-3 organ is one of those classic sounds that never seem to go out of style. Some synthesizer and arranger workstations provide a “drawbar mode” in which the musician can adjust the setting of nine virtual B-3 drawbars. When a workstation lacks real physical drawbars (the usual case), it’s often difficult to “play the ‘bars” during a tune. If the virtual drawbars respond to MIDI continuous control (CC) messages, then one of the many commercial MIDI controllers can fill the gap. However, a few instruments like the Yamaha PSR-S950 do not have sliders and the virtual drawbars do not respond to MIDI CC messages. (The S950 responds to a proprietary MIDI System Exclusive message instead.) I constructed a set of sliders to control the drawbars on the S950. The prototype consists of an Arduino UNO and a Sparkfun DangerShield. Here is a link to the source code.