Hans add-on board Rev B & Raspberry Pi Zero W

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Description

Hans is an add-on board made for the Raspberry Pi Zero W. It is powered from the 5V rail of a Eurorack case. MIDI Over i2c for ER-301 etc.

Features:

• Control the ER-301 and TXo Eurorack modules via MIDI and OSC (Serial, USB and Bluetooth MIDI).
• Send MIDI from Monome Teletype.
• Use it as a standalone MIDI processor or as an OSC to MIDI converter.
• ...

Technical details:

• Serial MIDI input and output.

• Two i2c busses on which Hans acts as a leader.

• A third bus on which Hans acts as a follower and thus can be used for converting i2c messages received from Teletype to MIDI.

Status

Achieved:

• OSC over UDP implementation (receiver), conversion to i2c, full set of ii commands.
• Bluetooth LE MIDI
• Custom hardware PCB (double i2c bus, pull-up resistors and power (w/ pwr protection) from the 5V rail of a Eurorack case)
• Serial midi IO
• MIDI over USB
• i2C follower on separate bus (Messages received from Monome Teletype via i2c converted to MIDI - BETA)

In progress:

• Documentation
• Full MIDI to i2c mapping

Under consideration:

• Support for more "followers" modules (Disting EX, W/, Ansible and Crow), technically, already possible but the commands need to be added to commands.js.
• Web interface (Settings)
• Support for "getters" commands
• Host and trigger custom scripts

Log

14/01/2021

Repository and project re-organization.

13/01/2021

Hardware REV C fully tested and working. This codebase was completely replaced by a Rust version. The Node.js version of the project is deprecated.

25/10/20

Hardware successfully tested. Although the actual node.js system used for sketching this app is functionnal, I've decided to move to another language and I'm currently rewriting the whole app in Rust!

23/10/20

Testing REV C PCB

20/09/2020

REV C PCB almost ready for production. Removed the MIDI "Thru" output. Replaced the hex-inverter with a single non-inverting buffer. Removed the duplicate row of "hardware I2c GPIO 2& 3" and added a row for "I2c following" mode (SPI1)

16/08/2020

REV B PCB sent to production. This new PCB features a serial MIDI IN/OUT/THRU header.

07/08/2020

Midi implementation. User defined Midi mapping + support for both Bluetooth midi and hardware midi connected via USB.

03/08/2020

Hardware successfully tested.

24/07/2020

PCB received, prototype built. Testing in progress.

08/07/2020

PCB sent to production.

07/07/2020

Prototype PCB design ready to be sent for production. It features a double i2c IO (regular hardware IO + software i2c on another set of GPIO) and a "safe" 5V input.