Hardware interface between headstages and a computer
Switch branches/tags
Nothing to show
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Type Name Latest commit message Commit time
Failed to load latest commit information.
gerber Update Gerber files Mar 4, 2014
licenses Added license files Aug 31, 2012




The Open Ephys acquisition board provides a convenient USB interface between up to four headstages and a computer. It features 8 channels of digital input, to sync acquisition with external devices, and 8 channels of digital output, to trigger optogenetic stimulation or behavioral feedback.

View on the Open Ephys website.

If you're interested in building your own acquisition board, we strongly recommend getting in touch with us via the Open Ephys contact page. Assembly instructions can be found here.


The Open Ephys headstages are powerful, but they can't run on their own. They need to receive precisely coordinated control signals that synchronize the Intan chip with the onboard analog-to-digital converter. The best way to generate these signals is with a field-programmable gate array (FPGA), a chip that can be instantly reconfigured to simulate multiple analog circuits in parallel. An FPGA inside the acquisition board is what controls the headstages and sends their data to a computer. Since the headstages can't be plugged directly into the Opal Kelly board, we needed to add a custom printed circuit board to relay neural data to the FPGA. And because we wanted the whole package to be easy on the eyes, we designed a case that can be 3D printed, CNC machined, or cast in plastic.

Current specifications

  • Simultaneous acquisition from 4 headstages (128 channels total)
  • up to 30 kHz sampling rate
  • 8 digital inputs controlled via software
  • 8 digital outputs controlled via software
  • 8 bidirectional ADCs (+/- 5V)
  • 8 DACs (+/- 5V)
  • USB 2.0, USB 3.0, or PCI express communication (depending on the Opal Kelly FPGA that is used)
  • 8 full-spectrum indicator LEDs

File types

  • .ai = Adobe Illustrator files; contain images of hardware
  • .brd = EAGLE board files; describe the physical layout of the printed circuit board
  • .sch = EAGLE schematic files; describe the electrical connections of the printed circuit board
  • .cam = EAGLE export files; contain instructions for translating between the .brd file and Gerber files
  • .png = image files
  • BOM.txt = contains link to Bill of Materials in a Google Doc
  • BOM.csv = text file containing all the necessary parts; can be viewed in Excel or any text editor
  • .md = Markdown files; most likely a README file; can be viewed with any text edtior
  • "gerber" files (.top, .bsk, .oln, etc.) = contain machine-readable instructions for creating the printed circuit board; these are sent to a fab house (such as Sunstone Circuits) for PCB production
  • .SLDPRT files = SolidWorks part files; contain CAD models of 3D components
  • .STL files = stereolithography files; can be sent to a rapid prototyping service (such as Shapeways) to create 3D objects
  • .eps files = specify design of acrylic top for laser cutting