# QT Py RP2040 USB to Serial MIDI Friends
## Overview
https://youtu.be/Ik_1kFg_URY
Did you know you can use a QT Py RP2040 as a USB to Serial MIDI converter? The QT Py RP2040, running CircuitPython code, receives MIDI messages over USB and then sends the messages out over serial UART. You can build small add-on boards, or friends, for TRS-A, TRS-B and DIN-5 MIDI out circuits that plug directly into the QT Py RP2040.
This concept was inspired by [Sandy Macdonald on Twitter](https://twitter.com/sandyjmacdonald/status/1516109671404347402). It makes for a compact and simple solution for interfacing hardware MIDI devices with USB.
The MIDI friend breakouts plug directly into a QT Py RP2040 with socket headers.
Versions for TRS-A, TRS-B and DIN-5 MIDI connections are shown in this guide. You can choose which one to build depending on your hardware MIDI device.
## TRS-A or TRS-B?
If you aren't sure which type of TRS connection your TRS MIDI device uses, you can [search for it on minimidi.world](https://minimidi.world/) to see if it uses TRS-A or TRS-B. TRS-A is currently the MIDI standard, but many devices out there have TRS-B sockets. The difference is that the 3V and TX serial connections are swapped on the audio jack.
## Prerequisite Guides and Resources
[Adafruit QT Py RP2040](https://learn.adafruit.com/adafruit-qt-py-2040)
[MIDI for Makers](https://learn.adafruit.com/midi-for-makers)
[minimidi.world Simplified Guide to TRS MIDI](https://minimidi.world/)
[TRS Stereo Jack Datasheet](https://cdn-shop.adafruit.com/product-files/1699/STX3120.pdf)
## Parts
### Adafruit QT Py RP2040
[Adafruit QT Py RP2040](https://www.adafruit.com/product/4900)
What a cutie pie! Or is it... a QT Py? This diminutive dev board comes with one of our new favorite chip, the RP2040. It's been made famous in the new [Raspberry Pi Pico](https://www.adafruit.com/pico) _and_ our [Feather...](http://www.adafruit.com/product/4884)
In Stock
[Buy Now](https://www.adafruit.com/product/4900)
[Related Guides to the Product](https://learn.adafruit.com/products/4900/guides)
### Breadboard-Friendly 3.5mm Stereo Headphone Jack
[Breadboard-Friendly 3.5mm Stereo Headphone Jack](https://www.adafruit.com/product/1699)
Pipe audio in or out of your project with this very handy breadboard-friendly audio jack. It's a stereo jack with disconnect-switches on Left and Right channels as well as a center ground pin. You can use any 3.5mm stereo cable with this jack. The pins are on 0.1" spacing so it plugs...
In Stock
[Buy Now](https://www.adafruit.com/product/1699)
[Related Guides to the Product](https://learn.adafruit.com/products/1699/guides)
### Breadboard-friendly MIDI Jack (5-pin DIN)
[Breadboard-friendly MIDI Jack (5-pin DIN)](https://www.adafruit.com/product/1134)
To celebrate the 30th Anniversary of the invention of MIDI we're carrying these handy 5-pin MIDI jacks. They're what you see on the back of nearly every synthesizer and drum machine. These are nice sturdy jacks, and breadboard-friendly, with all the pins on 0.1" spacing for easy...
In Stock
[Buy Now](https://www.adafruit.com/product/1134)
[Related Guides to the Product](https://learn.adafruit.com/products/1134/guides)
### Bakelite Universal Perfboard Plates - Pack of 10
[Bakelite Universal Perfboard Plates - Pack of 10](https://www.adafruit.com/product/2670)
Make your next project as you imagine it with prototyping perfboards that can easily be cut with scissors like these **Bakelite Universal Perfboard Plates**!
We wanted a perfboard that was both customizable and durable and
In Stock
[Buy Now](https://www.adafruit.com/product/2670)
[Related Guides to the Product](https://learn.adafruit.com/products/2670/guides)
### Super Scissors
[Super Scissors](https://www.adafruit.com/product/1599)
Save your scissors! Instead of using your nice shears (and dulling them) or wire cutters (not right for the job) - use these super scissors. They're meant for engineering/maker cutting jobs such as cutting plastic, leather, copper sheet/wire, even coaxial & ribbon cables. There's a...
In Stock
[Buy Now](https://www.adafruit.com/product/1599)
[Related Guides to the Product](https://learn.adafruit.com/products/1599/guides)
### Pink and Purple Woven USB A to USB C Cable - 1 meter long
[Pink and Purple Woven USB A to USB C Cable - 1 meter long](https://www.adafruit.com/product/5153)
This cable is not only super-fashionable, with a woven pink and purple Blinka-like pattern, it's also made for USB C for our modernized breakout boards, Feathers, and more. [If you want something just like it but for Micro B, we...](https://www.adafruit.com/product/4111)
Out of Stock
[Buy Now](https://www.adafruit.com/product/5153)
[Related Guides to the Product](https://learn.adafruit.com/products/5153/guides)
### Part: 20-pin 0.1" Female Headers - Rainbow Color Mix - 5 pack
quantity: 1
Socket headers
[20-pin 0.1" Female Headers - Rainbow Color Mix - 5 pack](https://www.adafruit.com/product/4160)
### Part: Break-away 0.1" 36-pin strip male header - Blue - 10 pack
quantity: 1
Plug headers
[Break-away 0.1" 36-pin strip male header - Blue - 10 pack](https://www.adafruit.com/product/4150)
### Part: 10Ω Resistor
quantity: 1
10Ω resistor for TX connection
[10Ω Resistor](https://www.digikey.com/en/products/detail/yageo/CFR-25JB-52-10R/340)
### Part: 30Ω Resistor
quantity: 1
30Ω resistor for 3.3V connection
[30Ω Resistor](https://www.digikey.com/en/products/detail/yageo/CFR-25JB-52-30R/1526)
- [Next Page](https://learn.adafruit.com/qt-py-rp2040-usb-to-serial-midi-friends/circuit-diagram.md)
## Featured Products
### Adafruit QT Py RP2040
[Adafruit QT Py RP2040](https://www.adafruit.com/product/4900)
What a cutie pie! Or is it... a QT Py? This diminutive dev board comes with one of our new favorite chip, the RP2040. It's been made famous in the new [Raspberry Pi Pico](https://www.adafruit.com/pico) _and_ our [Feather...](http://www.adafruit.com/product/4884)
In Stock
[Buy Now](https://www.adafruit.com/product/4900)
[Related Guides to the Product](https://learn.adafruit.com/products/4900/guides)
### Breadboard-Friendly 3.5mm Stereo Headphone Jack
[Breadboard-Friendly 3.5mm Stereo Headphone Jack](https://www.adafruit.com/product/1699)
Pipe audio in or out of your project with this very handy breadboard-friendly audio jack. It's a stereo jack with disconnect-switches on Left and Right channels as well as a center ground pin. You can use any 3.5mm stereo cable with this jack. The pins are on 0.1" spacing so it plugs...
In Stock
[Buy Now](https://www.adafruit.com/product/1699)
[Related Guides to the Product](https://learn.adafruit.com/products/1699/guides)
### Breadboard-friendly MIDI Jack (5-pin DIN)
[Breadboard-friendly MIDI Jack (5-pin DIN)](https://www.adafruit.com/product/1134)
To celebrate the 30th Anniversary of the invention of MIDI we're carrying these handy 5-pin MIDI jacks. They're what you see on the back of nearly every synthesizer and drum machine. These are nice sturdy jacks, and breadboard-friendly, with all the pins on 0.1" spacing for easy...
In Stock
[Buy Now](https://www.adafruit.com/product/1134)
[Related Guides to the Product](https://learn.adafruit.com/products/1134/guides)
### Bakelite Universal Perfboard Plates - Pack of 10
[Bakelite Universal Perfboard Plates - Pack of 10](https://www.adafruit.com/product/2670)
Make your next project as you imagine it with prototyping perfboards that can easily be cut with scissors like these **Bakelite Universal Perfboard Plates**!
We wanted a perfboard that was both customizable and durable and
In Stock
[Buy Now](https://www.adafruit.com/product/2670)
[Related Guides to the Product](https://learn.adafruit.com/products/2670/guides)
### Super Scissors
[Super Scissors](https://www.adafruit.com/product/1599)
Save your scissors! Instead of using your nice shears (and dulling them) or wire cutters (not right for the job) - use these super scissors. They're meant for engineering/maker cutting jobs such as cutting plastic, leather, copper sheet/wire, even coaxial & ribbon cables. There's a...
In Stock
[Buy Now](https://www.adafruit.com/product/1599)
[Related Guides to the Product](https://learn.adafruit.com/products/1599/guides)
### Pink and Purple Woven USB A to USB C Cable - 1 meter long
[Pink and Purple Woven USB A to USB C Cable - 1 meter long](https://www.adafruit.com/product/5153)
This cable is not only super-fashionable, with a woven pink and purple Blinka-like pattern, it's also made for USB C for our modernized breakout boards, Feathers, and more. [If you want something just like it but for Micro B, we...](https://www.adafruit.com/product/4111)
Out of Stock
[Buy Now](https://www.adafruit.com/product/5153)
[Related Guides to the Product](https://learn.adafruit.com/products/5153/guides)
### 20-pin 0.1" Female Headers - Rainbow Color Mix - 5 pack
[20-pin 0.1" Female Headers - Rainbow Color Mix - 5 pack](https://www.adafruit.com/product/4160)
Female header is like the duct tape of electronics. It's great for connecting things together, soldering to perf-boards, sockets for wires or break-away header, etc. We go through these real fast, and thought that given how handy they are, we'd offer them in a pack of five!
Each...
In Stock
[Buy Now](https://www.adafruit.com/product/4160)
[Related Guides to the Product](https://learn.adafruit.com/products/4160/guides)
### Break-away 0.1" 36-pin strip male header - Blue - 10 pack
[Break-away 0.1" 36-pin strip male header - Blue - 10 pack](https://www.adafruit.com/product/4150)
In this world, nothing can be said to be certain, except we need headers, headers, and _more headers_!
Each pack contains ten blue **36-pin 0.1" pitch break-away male headers.** These are a little extra special in that the plastic holding the pins...
In Stock
[Buy Now](https://www.adafruit.com/product/4150)
[Related Guides to the Product](https://learn.adafruit.com/products/4150/guides)
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