# Tsunami Super WAV Trigger MIDI works with a keyboard but not with an Arduino

**URL:** <https://community.sparkfun.com/t/tsunami-super-wav-trigger-midi-works-with-a-keyboard-but-not-with-an-arduino/43459>\
**Category:** Sound & Audio\
**Created:** [February 8, 2022, 1:44pm UTC](https://community.sparkfun.com/t/tsunami-super-wav-trigger-midi-works-with-a-keyboard-but-not-with-an-arduino/43459 "2022-02-08T13:44:53Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![XenonJohn](https://avatars.discourse-cdn.com/v4/letter/x/49beb7/32.png) [@XenonJohn](https://community.sparkfun.com/u/XenonJohn)\
**Post date:** [February 8, 2022, 1:44pm UTC](https://community.sparkfun.com/t/tsunami-super-wav-trigger-midi-works-with-a-keyboard-but-not-with-an-arduino/43459/1 "2022-02-08T13:44:53Z")

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Problem: If I plug a regular MIDI keyboard into my Tsumani Super WAV Trigger set up in mono mode, with mono WAV files on the SD card, it plays the files just fine when I play the keyboard.

However, if I use a Teensy (similar to Arduino) board with an output to a MIDI socket, it does not work.

I have a Teensy board using the MIDI.h library to send MIDI.sendNoteOn(note, 127, 1); // notes between 48 and 87, maximum volume, MIDI Channel 1 and similar MIDI.sendNoteOff commands out via a suitably wired 5 Pin MIDI socket.

- If I plug an AKAI wireless MIDI Bluetooth transmitter into this socket it works fine when paired with an iPad for example running a synth program.

- If I connect this using a 5Pin MIDI to USB adapter to my laptop and use midiOx program to examine the MIDI commands coming in, I just see MIDI On and MIDI Off commands exactly as expected along with the note MIDI values, on MIDI channel 1.

- Therefore, I assume my wiring and Teensy software is correct as it is working fine with everything except the Tsunami.

However,

If I connect this to the MIDI input of my Tsunami Super WAV Trigger, (5 Pin MIDI plug pins 4 and 5 wired to 4 ands 5 MIDI inputs on the Tsunami board) I hear no sound from the headphones. I have 4 and 5 wired correctly as

- If I plug a MIDI keyboard, using this same MIDI lead, into the Tsunami, the Tsunami works absolutely fine.

Am I missing something obvious here? I know I can use an Arduino to control the Tsunami via serial but I would like to do it via MIDI ideally.

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**Author:** ![robertsonics](https://yyz1.discourse-cdn.com/sparkfun/user_avatar/community.sparkfun.com/robertsonics/32/6841_2.png) [@robertsonics](https://community.sparkfun.com/u/robertsonics)\
**Post date:** [February 9, 2022, 9:44pm UTC](https://community.sparkfun.com/t/tsunami-super-wav-trigger-midi-works-with-a-keyboard-but-not-with-an-arduino/43459/2 "2022-02-09T21:44:59Z")

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Difficult to say without looking at the signal on a scope. MIDI uses a 20mA current loop rather than a straight voltage, and that requires the correct combination of voltage and resistors. I suppose it’s possible that the 3.3V supplied by the Teensy isn’t sufficient to result in the correct current through the opto-isolator. But I’m guessing…