For my purposes, this works:
midi_send(9, 176, 99, 1)
midi_send(9, 176, 98, 95)
midi_send(9, 176, 6, val)
This article helps a lot and explains what CC 99, 98, and 6 (and 38) do:
- CC 99 sets the MSB
- CC 98 sets the LSB
- CC 6 sets the actual value
- CC 38 appears to be used optionally to set a ‘Fine’ value. I’m pretty sure it needs to be defined by the vendor though.