Modified Frame-projected Independent Fiber Photometry (FIP) System_Triggering system

Frame-projected independent fiber photometry (FIP) is a method to measure fluorescent sensor signals through optical fibers implanted in living animals, using a camera to record video of the fiber faces. To precisely control timings of excitation and camera frame acquisition for FIP, and of other external stimulation apparatus (e.g. LEDs for photo-stimulation), we use a Teensy 4.1 microcontroller, which generates voltage pulses without relying on continuous communication with the operating system of the experimental computer for timing. This protocol is for the 3 excitation LED + 2 collection CMOS cameras design.