Trigger camera remotely
There are various methods to remotely trigger a still photograph camera to start taking pictures in the air, and to shut the camera down before landing to avoid damage to its lens. Read this 3DR webpage for a detailed description of how to do this using CHDK.
These methods basically involve:
- Installing a CHDK firmware on a compatible Canon camera. The firmware is installed on the SD card, and does not overwrite the camera’s original firmware. This process is reversible.
- Connecting the camera to your radio receiver or to the APM via a CHDK-USB cable (gentWIRE-USB or E-flite LED controller). See Flightriot.com’s excellent video on how to build such a cable.
- Running a customized script on the camera that instructs the camera how to respond to signals from the radio receiver or APM.
The following is an extremely simple ‘.bas’ script written by ConservationDrones.org. (Download it here. Place unzipped ‘Remote.bas’ file in the Script folder of the camera’s SD card. Read this 3DR webpage for details.)
@ConservationDrones Remote Script 9/2013
if is_key “remote” then goto “loop” else goto “wait”
if is_key “remote” then goto “loop” else shut_down
To start taking pictures, flick a switch on your radio transmitter (or output a PWM>1900 signal from APM). The camera will continue to take pictures repeatedly as long as the switch is in the ‘ON’ position (or PWM>1900). To stop taking pictures and shut the camera down, simply flick the transmitter switch back to the ‘OFF’ position (or output a PWM<1100 signal from APM). See video below for a quick demonstration.