The Hexboard in Design Concepts Posted 18 Jan 2010 It seems to me that you could achieve this by using a switch that can record the first depression of the key, then the release of the key, sending a signal both times. This isn't how velocity sensitivity works. Keyboards have 2 switches per key, a known distance apart that are pressed one after the other. The time difference between the 2 switches being triggered is used to calculate the velocity, which is sent as the second byte of a MIDI Note-on message. When you release the key, the keyboard detects this and sends a MIDI Note-off.