Wired Midi

[Kfen5150]

Guys sorry if this has been covered,I can't seem to find what i need.
Could someone point me in the direction of what i need to
build a wired version of this.
Thanks in advance

[Builty]

Refer here:
https://github.com/Builty/TonexOneController/blob/main/HardwarePlatforms.md#midi

[Kfen5150]

Excellent , Featherwing on its way !!

Donation through paypal shortly. Where do i find the link?
Many thanks

[rmenes]

if you use waveshare zero you dont need an optoisolator, and thus you dont need the feather wing.
I used wired midi on the waveshare zero using a TRS connector, like the new boss pedals use.

[Kfen5150]

Would you be able to show me how it is wired please?

[Kfen5150]

I'm hoping to use just a regular midi footswitch, not a chocolate,
Into a Waveshare zero and out to the tonex. if that makes sense.

[rmenes]

Would you be able to show me how it is wired please?

Hi TRS MIDI to DIN is below, you can use as reference

TRS = Tip, Ring, Sleeve. So the sleeve goes to the Ground of the Waveshare Zero.
The Ring goes to the 3.3V port in Waveshare Zero
The Tip goes to the pin 5 of the Waveshare Zero

I made a small controller with the waveshare zero like this one.

You willl ned a TRS to DIN cable like this

And this is the video of it working with a normal MIDI controller

https://www.youtube.com/watch?v=JyMn65JolSQ

[Kfen5150]

Fantastic, thank you, just finished wiring to my meloaudio midi commander and it works a treat.

[johnk877]

I tried with my Boss FS-1 WL, doesn't seem to work... Is a resistor required from sleeve to 3.3v port of waveshare zero?

[Builty]

John, make sure you have enabled Midi serial in the web config page, and set the channel too.

[johnk877]

Yes, I have enabled wired midi. Do I need to add resistors between pin 5 and tip as well as 3.3v and sleeve? Also, my controller takes a 3.5mm TRS and not 5pin din. But that should not make a difference right?

[johnk877]

[Builty]

3.5 mm should not matter at all. For the resistor question, I haven't attempted to run Midi without the featherwing kit. Its not easy for more to comment in the specifics of that.
I can say however that any UART receiver pin needs to idle in the high state. Very often a pullup resistor is used in order to ensure the input does idle high.
Whether that is definite depends on the circuit connected to it. If it floats when idle, then a pull up resistor is required for sure.
Adding a 10k pullup from RX to 3.3v would be a safe thing regardless and certainly worth a go.

[Sundeeprk93]

Yes, I have enabled wired midi. Do I need to add resistors between pin 5 and tip as well as 3.3v and sleeve? Also, my controller takes a 3.5mm TRS and not 5pin din. But that should not make a difference right?

I think, the tip goes to the pin 5 on the board. Ring goes to the 3.3v and sleeve goes to the ground.. the sleeve must not be connected to pin 5… hope this helps.. let us know if it works…

on the other note, i was considering turning my rig, wired, daisy chaining 2-3 pedals (including tx1).. and im really confused about these resistors that builty is asking yo connect.. can you more specific why it is very important to connect the resistors for smoother operation?

[Builty]

Midi uses a form of serial communications, where the receiver pin is set to high or low at a specific timing. On the ESP32-S3, the recieve pin is an input pin. An input pin needs to be driven to either high or low state. If it is left without anything setting it high or low, it will tend to pick up noise and randomly read as high or low.

Now many microcontrollers have the ability to use internal pullup or pulldown resistors, that can be enabled in the firmware to ensure the pin is not floating. In the current release, there is no internal pullup resistor enabled. In the next release it does have an internal pullup enabled.

In your case, the need for a resistor really depends on how things are wired. Its very common to use a 10k ohm resistor from the receiver input pin to 3.3v, to guarantee that the pin is never floating.
It's possible for the external circuits connected to also do this job, but doing on the controller also is the safest way.

[johnk877]

I managed to build a midi out board using the instructions here: https://diyelectromusic.com/2021/02/15/midi-in-for-3-3v-microcontrollers/. Good alternative if you don't have access to the adafruit board like me