The MIDI module includes a small, general purpose 16-bit MCU (Texas Instruments’ MSP430) that converts control voltages (CV) to MIDI. It is designed to be hackable. If you are adventurous enough, you can reprogram the code for your own purposes. The software is Open Source and can be cloned via Github (see Nexus repository). The code is based on the ubiquitous Arduino platform to make it easy to hack into.

You need a programming device to update the MCU Module firmware. There’s a lot of MSP430 programmers available out there, but the question is. “What is the cheapest we can get?”. Answer: the MSP430 launchpad dev board from Texas Instruments. Dev boards from chip manufacturers are often heavily subsidized, making them very inexpensive. The table below shows the price comparison for a few MSP430 programming devices including the MSP430G2 Launchpad Development Board.

What we need:

1. Nexus MCU Module
   
   
2. MSP430G2 Launchpad dev board
   
3. Female-to-female jumper wires
   
4. USB Type-B mini cable
   

Step 1. Remove all header shunts

Carefully remove the shunts highlighted on the dev board. RX/TX pins should also be removed to avoid data collision when programming an external MCU.

Step 2. Connect the jumper wires to the Launchpad

Follow proper jumper wire color coding indicated in the pictures below.

Step 3. Connect the jumper wires to the MCU Module

Step 4. Connect the USB Cable

Step 5. Install Energia IDE

Follow this link for Mac, Windows and Linux installation guides.

Step 6. Download and clone the firmware

Follow this link. You can download or clone the repository to your local drive.

Step 7. Flash the Firmware

1. Open the source file using the Energia IDE.
2. Click upload.
3. Wait until the app indicate finish upload without errors.