Thx for the suggestions. I installed kmidimon to watch the midi events.
I can't send note messages from my pedal, at least I don't know how to do that. The pedal emits CC messages and PC messages. I use the CC messages since you can hit the same pedal twice and get the same 'data1' value each time. The PC pedals will toggle between two PC numbers generally.
So in the log below the last number on each line is 'data2' according to kmidimon. That indicates whether the effect on the effect pedal is on or off. Not relavant to operating sooperlooper. 'data1' is either 21, which I have assigned to Record, or 22 which is assigned to Pause.
The pattern seems to be this:
162794,453.1748,132:0,1,Control change,21,127, *21 = recording*
164992,457.7535,132:0,1,Control change,21,0, *recording stopped*
166263,460.4013,132:0,1,Control change,22,0, *22 = pause. but nothing happens!*
167383,462.7348,132:0,1,Control change,22,127, *now pause happens*
186836,503.2614,132:0,1,Control change,21,127, *recording*
189353,508.5054,132:0,1,Control change,21,0, *recording stopped*
190419,510.7263,132:0,1,Control change,22,127, *pause works!*
It seems like sooperlooper is ignoring the 22,0 message for some reason, but once it recives a 22,127 message it starts recognizing the 22,0 message again.