MIDI on ESP8266 Wemos D1 Mini

[undercurrent77]

Context

Please answer a few questions to help us understand your problem better and guide you to a solution:

• What board are you using ?
  • Arduino Uno rev3
  • Wemos D1 Mini ESP8266
• What version of the Arduino IDE are you using ?
  • Tried with both 1.8.19 and 2.3.0
• How are you using MIDI ?
  • [X] Hardware Serial (DIN plugs)
  • [ ] USB
  • [ ] Other (please specify)
• Is your problem related to:
  • [ ] MIDI Input (reading messages from other devices)
  • [X] MIDI Output (sending messages to other devices)
• How comfortable are you with code ?
  • [ ] Complete beginner
  • [X] I've done basic projects
  • [ ] I know my way around C/C++
  • [ ] Advanced / professional

Describe your project and what you expect to happen:

I've followed along with the example found on the Notes and Volts video found here: https://www.youtube.com/watch?v=rmfAqg9O_os&list=PL4_gPbvyebyH2xfPXePHtx8gK5zPBrVkg&index=5

When I upload the code to my arduino uno rev 3, everything works as expected. I'm using the morningstar midi monitor website and am seeing note 60 turn on and off. However, when I upload the same code to my wemos d1 mini esp8266 nothing happens. The builtin led blinks, so the code has uploaded properly but I don't see any midi messages being transmitted. I have the data line for the serial midi plugged into the TX pin on GPIO1.

Here is my code:

#include <MIDI.h>

MIDI_CREATE_DEFAULT_INSTANCE();

void setup() 
{
  pinMode(LED_BUILTIN, OUTPUT);
  MIDI.begin(MIDI_CHANNEL_OFF);
}

void loop() 
{
  digitalWrite(LED_BUILTIN, HIGH);
  MIDI.sendNoteOn(60, 127, 1);
  delay(1000);
  MIDI.sendNoteOff(60, 0, 1);
  digitalWrite(LED_BUILTIN, LOW);
  delay(2000);
}

-->

## Describe your problem (what does not work):

Midi code works on Arduino Uno rev 3 but not wemos D1 mini esp8266

[undercurrent77]

Total brain cramp on my part. The logic level of the RT and TX pins are 3.3v on the D1 Mini even though it has the 5V output on the board. Used a level shifter and the code worked as expected.