Raspberry Pi Pico MIDI Splitter – Part 2

This is the build guide for my Raspberry Pi Pico MIDI Splitter.

If you are new to microcontrollers, see the Getting Started pages.

Bill of Materials

• Raspberry Pi Pico MIDI Splitter PCB (GitHub link below)
• Raspberry Pi Pico
• 1x H11L1 optoisolator
• 3x 74HCT14 (has to be the HCT version, not the HC version)
• 19x 220Ω resistors
• 1x 470Ω resistor
• 1x 1N914 or 1N4148 diode
• 4x 100uF ceramic capacitors
• 10x 5-pin 180 DIN sockets (see PCB and photos for footprints)
• Optional: 1x 6-pin DIP socket
• Optional: 3x 14-pin DIP sockets
• Optional: 2x 20-pin header sockets for the Pico

Build Notes

A straight forward “low to high” approach should be taken.  Here is the recommended soldering order:

• Resistors and diode.
• 14 pin and 6 pin DIP sockets (if used).
• Capacitors.
• Pico 20-way headers (if used).
• DIN sockets.

Here are some build progress photos.

Testing

I recommend performing the general tests described here: PCBs.

Applications

This will run the code from my Raspberry Pi Pico MIDI Channel Router directly, but it doesn’t make use of the UART connected MIDI OUT.

It can also be used with the code from my Raspberry Pi Pico Multi MIDI Router but with the number of RX UARTS set to zero.  This is the configuration that provides 8 PIO output ports:

UART_BAUD = 31250
RX_PIN_BASE = 6
RX_NUM_UARTS = 0
TX_PIN_BASE = 6
TX_NUM_UARTS = 8 # Ports 2-9
HW_NUM_UARTS = 2 # Ports 0-1

PCB Errata

None at present.

In terms of enhancements, it might be useful to include some headers to break out the second UART port too.

Find the PCB on GitHub here.

Closing Thoughts

Many thanks to Seeed Fusion (as always) for the cost effective and speedy delivery of my boards.

Full disclosure: these boards were discounted using vouchers sent to me by Seeed following previous links from my posts.  Otherwise, I have no specific links to Seeed or their service.

As always, it is possible I might have one or two spares, so feel free to get in touch if you want to.

Kevin