Issue:
How to use the Scorpion general purpose input / output (GPIO) pins.

Solution:
IMPORTANT NOTE: To use the GPIO functionality, the Scorpion must have firmware version 0.0.0.29 or any later version installed.

The Scorpion comes with a 12-pin GPIO connector on the back that allows the camera to interact with external devices. It can be configured to trigger on an external electrical signal or produce a similar signal that allows devices external to the camera to be synchronized to the camera. Input and output of these signals is achieved via the Scorpion's general-purpose IO pins. A diagram detailing the layout of the GPIO connector can be downloaded here.

It is important to note that the Scorpion is virtually identical in its GPIO behaviour to the Dragonfly, so for in-depth information on using the GPIO pins download the Dragonfly Technical Reference from our downloads page.

However, there is one key difference between the Dragonfly and Scorpion external trigger behaviour. The default pin for externally triggering a Scorpion is IO0 (IO2 for a Dragonfly). In addition, IO0 on the Scorpion is not a weak pull up, which means it cannot be externally triggered by shorting IO0 to GND. Therefore, to reliably trigger the camera, IO0 must be connected to +3.3V each time.

Related Articles:
1.) Can I externally trigger my Dragonfly camera even with multiple cameras on the bus?
2.) Hooking a standard Black Burst generator to the external trigger pin on a Dragonfly camera
3.) Buffering a GPIO pin strobe output signal using an optocoupler to drive external devices.