666af52e_Midignusbuino___SGMK_SSAM_WIKI__Description
[Constant] MIDI_CHANNELAFTERTOUCH [Data] pressure [Description] 
Channel Pressure (After-touch). This message is most often sent by pressing down on the key after it "bottoms out". This message is different from polyphonic after-touch. Use this message to send the single greatest pressure value (of all the current depressed keys)
Midignusbuino - SGMK-SSAM-WIKI
Description