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EMOTIV Extender triggering
EMOTIV Extender’s hardware triggering feature allows you to mark external events for post-processing. The input trigger pulses are injected into a headset’s data stream within +/-1 sample. There is a fixed 60ms delay between the trigger and the channel signal data which is due to the filter delay for the channels.
The trigger pulse is shown in EmotivPRO as a pink line and is also saved in the hardware column when exporting a file.
Every EMOTIV Extender comes with a 1m trigger cable. The cable has two tinned wires: red and black that can be connected to an external trigger source. The input polarity of the trigger is reversible and utilizes an opto-coupled photo transistor Vishay VOL628A (see datasheet). This component requires a minimum of 1mA forward current and maximum of 60mA. The input design has an internal limiting resistor of 1kOhm. The trigger input voltage needs to be between 2.5 and 15V, and can be driven directly from an Arduino or a parallel port. Please see the Extender User Manual for details.