Mounting and Connecting

Mounting

The commutator has several holes that can be used to mount it on 80/20 aluminum extrusion using t-nuts or a standard mechanical breadboard. For example:

For custom mounting solutions, you can find the 3D mCAD files in the following repos:

• For any commutator with a Teensy (i.e. if your commutator has a Micro-USB port)

• For any commutator with an RP2040 (i.e. if your commutator as a USB-C port)

  • Coax Commutator

  • Dual Coax Commutator

  • SPI Commutator

These files can be be opened and the design dimensions can be measured using mCAD software that supports either SolidWorks files (e.g. eDrawings) or STL files (e.g, FreeCAD). Both file types are available in the repositories linked above.

More information on the best location to mount the commutator is available on the Tether Management & Headstage Counterweight page.

Connecting

Coax Commutator

1. USB Connector

The commutator receives power and communicates to the PC over USB through this interconnect. Newer commutators use USB-C. Older commutators use Micro-USB.

2. Top SMA Connector

The commutator’s stator connects to a stationary data acquisition device that has a coaxial port (e.g. Miniscope DAQ or ONIX breakout board) through this SMA interconnect.

3. Bottom SMA Connector

The commutator’s rotor connects to a freely moving animal headstage that has a coaxial connector through this SMA interconnect.

SPI Commutator

1. USB Connector

The commutator receives power and communicates to the PC over USB through this interconnect. Newer commutators use USB-C. Older commutators use Micro-USB.

2. Top SPI Connector

The commutator’s stator connects to a stationary data acquisition device that has a SPI port (e.g. the Open Ephys Acquisition Board) through this 12-pin Omnetics PZN-12 interconnect.

3. Bottom SPI Connector

The commutator’s rotor connects to a freely moving animal headstage that has a SPI connector through this 12-pin Omnetics PZN-12 interconnect.

Tip

• Some USB cables only supply power. Confirm your USB cable transfers both power and digital signals.

• Source USB and coax cables from a reputable vendor such as Digikey, Mouser, or Open Ephys.

• Source your tether from Open Ephys or make your own.

• For animal behavior experiments, manage cables such that they do not interfere with the tether when the animal moves.