teensy control of Reaper?


Hello, I'm kinda ignorant about both MIDI and Reaper. Hoping someone here can show me the ways.

Using the Teensy example code "Buttons," I can send a note via button press to a Reaper track and get it to play using the ReaSynth VSTi.

I'm now trying to use the Teensy example code "Analog Control Change" to control Reaper. This doesn't seem to work in that I can never control anything in Reaper that I can tell. So this could in fact be a Reaper question.

In the Reaper prefs, I see the Teensy MIDI device on the input side. All 3 "Enable Inputs" are selected (track record, all midi inputs, control messages). I've set control messages to channel 2.

I'm attaching the sketch, which is a merge of the Buttons and Analog Control Change examples sketches. I have 2 pots wired in. The sketch sends the two analogRead values to the serial port to confirm there's an actual signal. Those same pot values (0–127) are being sent using sendControlChange( ) to Reaper's midi channel 2. But I don't know how to check in Reaper if/when/where it's getting those values for control. I'm using the control values found in the sketch: 10 for pan and 11 for volume.

So what should I look for in Reaper?

Thnx in advance for putting ups with the newbies.


  • midi-note-control.ino
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If you enable a track recording and set the Input to MIDI >> Teensy >> Channel (or all channels) you should be able to see a midi comm indicator (yellow square blinking in the default theme).
In Preferences/MIDI Devices, the Teensy Input should have "Control" enabled (black dot).
Furthermore, you can add a JS: MIDI Logger plugin to the track and it will show all the midi data received on that track.
In the VSTi, like ReaSynth Click on the "Param", then "Learn", choose the parameter you want to control via CC and then move the pot on the Teensy so it will send CCs. Reaper should detect the channel/number and assign that controller to the parameter.
@Pio thanks!

MIDI Comm Indicator: I do see a yellow square blinking in part of the track indicator. That seems to check out.

MIDI Logger: Took me a while, but by experimenting I figured out how to parse the colors and the midi commands and the arguments. There's more data in the logger but I don't know what it is.

ReaSynth Param/Learn; YES, this is what I was missing. I was able to choose the parameter and to control and adjust the control as needed with the pot. Makes more sense now!

Thanks again. Not sure if this is the best forum to ask noob MIDI questions. I need more manual reading and MIDI understanding than anything...