Open Sound Module

Description

The Open Sound Module is a WiFi connectivity module. It sets up a wireless network connection directly with your modular synthesizer. The OSM has two CV inputs and two CV outputs, along with two trigger inputs and outputs, for bi-directional wireless communication.

Use the OSM to connect your modular synthesizer to your mobile phone, tablet, laptop, local network or the mighty internet. Use two OSMs to connect together two racks, whether they are in the same room, or even the same continent. Use many to make the biggest modular synthesizer in the world!

The OSM communicates using the OSC protocol. It can connect to your local WiFi network or set up its own access point. The Open Sound Module embeds a small web server, enabling you to control and configure the device with a browser.

Video

Specifications

Overview

• WiFi: 802.11b/g/n
• Security: WEP/WPA/WPA2
• Access Point and WiFi Client
• Embedded Open Sound Control server
• Embedded web server
• 12bit Analogue to Digital converters
• 12bit Digital to Analogue converters
• Latency down to 12ms round trip (send and receive)

Connections

• 2 CV inputs
• 2 CV outputs
• 2 gate/trigger in
• 2 gate/trigger out

Dimensions

• Width: 6HP / 101.30mm
• Height: 3U / 128.50mm
• Depth: 32mm
• Weight: tbc

Power

• 10-pin Doepfer/Eurorack
• PTC fuse and diode protected
• +12v: 250mA
• -12v: 20

Impedance

• Outputs: 1k
• Inputs: 100k

Messages

The module sends an OSC message when there is a change in the signal connected to an input jack. When it receives a matching OSC message it changes the signal at the corresponding output jack. Default address mappings and value ranges are shown below, they can be changed in the web configuration.

Triggers
Default mappings: /osm/a/tr and /osm/b/tr
OSM sends trigger messages with one integer argument: 0 for off / low, 1 for on / high.
The module handles trigger input messages with either no argument, with an integer argument, or with a float argument.
No argument: toggle.
Integer argument: 0 for off, 1 for on.
Float argument: less than 0.5 for off, more than 0.5 for on.

CV
Default mappings: /osm/a/cv and /osm/b/cv
OSM sends CV messages with one float argument: 0.0 to 1.0 for a unipolar input signal from 0 to 5v, or -1.0 to 1.0 for a bipolar input signal from -5 to 5v.
The module handles CV messages with either a float or an integer argument.
Float -1 to 1, or integer 0 to 4095 (12 bits) for an output signal from -5 to 5v.

Status
Default mapping: /osm/status
The message contains a string with the module’s current IP address and local (receiving) port number.

For usage instructions see the Open Sound Module website.

Open Hardware

The Open Sound Module is Open Source and Open Hardware, published under the Gnu GPL.
Code and schematics is available on GitHub.

There is also a dedicated Open Sound Module website.