Hi all,
I'm wanting to set up a camera trap using a laser and detector trip wire being "watched" by a PICAXE which in turn tells the camera to fire. It could probably be done without a PICAXE using some careful circuitry, but having the PICAXE just gives that extra degree of felxibility in the final system should I want to change how it works, such as adding delays and logic statments with other detectors. Also, I've got a few 08 chips lying around which wont otherwise get used.
The canon camera remore release cable is just a 2.5mm stereo jack. Tip is shutter fire and ring is AF (auto focus). When either tip or ring are connected to the base, it takes a picture or just focuses respectively. On pinouts on the web, the base of the jack is refered to as ground.
Thing is, all the pinouts on the web tell you this much but they don't tell you how this is being used by the camera. I think there could be two ways:
1. tip and ring are being monitored by a microcontroller and are just seen as a logic low then acted upon (most likely I think)
2. the tip and ring are actually part of the circuit that makes the shooting happen, e.g. when you connect tip to base, current can then flow into actuators and stuff to make the shutter actuate.
Obviously, option two means much more current would be flowing through whatever it is that connects tip or ring to the base.
I tested it with an ameter and got no current going through whatsoever, though connecting the probes was making it fire off shots. the multimeter was on the right setting, cables in the right holes to read current. Even on the microamps setting it didn't read anything.
To me, that suggests approach 2 is being used as you would expect very little current to flow in that method. However, could there be a chance that a higher current is flowing for a very short amount of time?
The reason I want to know is because I would like to connect the tip and ring to PICAXE output legs, connect the base of the jack to the PICAXE circuit's ground (leg 8 on a PICAXE08). Then I can focus and fire by putting those outputs low, connecting them to ground and thus to the base of the jack. The legs can only take 20ma though of course, so I need to know the current.
Thanks in advance for any help,
David
I'm wanting to set up a camera trap using a laser and detector trip wire being "watched" by a PICAXE which in turn tells the camera to fire. It could probably be done without a PICAXE using some careful circuitry, but having the PICAXE just gives that extra degree of felxibility in the final system should I want to change how it works, such as adding delays and logic statments with other detectors. Also, I've got a few 08 chips lying around which wont otherwise get used.
The canon camera remore release cable is just a 2.5mm stereo jack. Tip is shutter fire and ring is AF (auto focus). When either tip or ring are connected to the base, it takes a picture or just focuses respectively. On pinouts on the web, the base of the jack is refered to as ground.
Thing is, all the pinouts on the web tell you this much but they don't tell you how this is being used by the camera. I think there could be two ways:
1. tip and ring are being monitored by a microcontroller and are just seen as a logic low then acted upon (most likely I think)
2. the tip and ring are actually part of the circuit that makes the shooting happen, e.g. when you connect tip to base, current can then flow into actuators and stuff to make the shutter actuate.
Obviously, option two means much more current would be flowing through whatever it is that connects tip or ring to the base.
I tested it with an ameter and got no current going through whatsoever, though connecting the probes was making it fire off shots. the multimeter was on the right setting, cables in the right holes to read current. Even on the microamps setting it didn't read anything.
To me, that suggests approach 2 is being used as you would expect very little current to flow in that method. However, could there be a chance that a higher current is flowing for a very short amount of time?
The reason I want to know is because I would like to connect the tip and ring to PICAXE output legs, connect the base of the jack to the PICAXE circuit's ground (leg 8 on a PICAXE08). Then I can focus and fire by putting those outputs low, connecting them to ground and thus to the base of the jack. The legs can only take 20ma though of course, so I need to know the current.
Thanks in advance for any help,
David
