Hi all. I purchased a new Runcam 2 for my Flamewheel 450 quad only to discover that there is no way to run a remote shutter trigger. Nothing came up on forum searches so I came up with one myself. I'm running a Pixhawk APM and use Aux5 in Relay mode for the camera trigger source. I opened up the Runcam and took some measurements on the shutter switch. It's a PCB mounted switch with four solder legs. The two legs closest to the rear of the camera are at ground potential. The two legs closest to the front of the camera are normally open and sit at 3 volts. When you press the switch it closes and pulls the 3 volt line to ground. Simple enough. I carefully soldered two small wires, one to the ground and one to the signal contacts. Then I drilled two very small holes (.040") in the side of the top case just ahead of the USB port and ran the wires out, using a little super glue to secure them.
Next, I needed an open collector inverter circuit to convert the Pixhawk relay output (zero to 3.7 volt transition) to a high-to-low pull down for the camera. This was accomplished simply with a 2n3904 (ore equivalent) transistor with a 2.2k ohm series resistor to the base, emitter grounded, and open collector connected to the camera signal line.
I programmed the Pixhawk for a 0.5 second camera trigger and presto, remote triggering of the Runcam2. I can now easily turn a video recording on or off in flight using the channel 7 Camera Trigger setting, or fire a still photo from the Do_Digicam_Control or Do_Set_Cam_Trig_Dist mission commands.
It works great. Let me know if you have any questions about implementation. You have to be very carefully soldering inside the Runcam. Space is limited and there is high potential for a solder bridge somewhere unwanted.
Doug
Replies
Hi,
It is possible to trig recording from the USB connector using simple TTL pulses. No need to open the camera.
The USB must be configured with the apps to "Remote Control" instead of "mass storage".
Then 85ms double pulses trig on/off recording, or take a picture in the camera mode.
Successfully tesed, controlling the runCam2 with a dsPIC (plane project). Further details here: https://lubin.kerhuel.eu/post/runcam-remote-control-cable/
Lubin
Doug,
Thanks for the reply. I did get it to work. I used a P2N2. I can now turn on/off and start/stop recording with a switch on my Taranis. The Runcam is in the front of an RC submarine and I can't get to it unless I pull the entire electronics board out. Now I can control it without that hassle.
John
John, Yes that should work fine. The input resistance to the 3904 inverter is 2.2Kohms so the load current seen by your Arduino high output should only be about 1.5ma. Let me know how it works out.
Doug
jjvb said:
Doug,
Regarding your Runcam 2 switch trigger. I'm thinking this could be accomplished using an arduino for input. I want to be able to turn on/off and start/stop recording with a switch on my transmitter. Could I use the same setup but write high or low to the base from a digital pin on the arduino? Writing high would bring the input line from the switch to ground. Thanks.
John
Mike,
The switch inside the Runcam has four solder legs on it; the front two (closest to the lens) are in parallel and connected to the signal line on the PC board. The rear two are also in parallel and connected to ground. If you wanted to hack an external switch in, just run a wire from one of the front two legs, and a wire from one of the rear two legs and connect them to a normally open push button switch externally. The external switch should then function just like the internal switch did. This all assumes that the internal switch failed in an open state. If it failed closed, then you will need to remove it first.
Doug
I have a Runcam 2 with a faulty shutter switch. From your experience, is there any way to hack a new switch in to substitute for the bad one? I can solder decently, but I'm not quite understanding your explanation of the 4 legs of the switch on the RunCam board.
Thanks,
Mike