Frame2TTL Wiki

Frame2TTL is a device for measuring the instant an LCD monitor updates its screen. It generates a TTL pulse when the patch of screen beneath its sensor switches its pixels between minimum and maximum intensity. The output signal is used to precisely align the frames of a visual stimulus with concurrently acquired physiology and behavior measurements.  

The device is powered by an Arduino-compatible microcontroller - Teensy 4.0, from PJRC. The controller reads a light sensor positioned above a patch of pixels in the corner of the display. It reports frame updates via TTL, and also outputs a continuous analog signal proportional to measured light intensity. The mechanical parts of Frame2TTL can all be 3-D printed or ordered from major industrial suppliers, with the exception of the printed circuit board. The cost of all necessary parts is ~$190 USD excluding shipping and 3D printing filament.

Frame2TTL was originally developed by Sanworks LLC for Kvitsiani and Yonehara labs at Aarhus University. It is open source hardware, licensed freely under GPL v3.0. All code, firmware and CAD files are available in our Frame2TTL repository. Please read our terms and conditions before using this device in your research.