OK, I have searched and read many things and gone through a lot of script testing with this wire that I thought was good. I have a USB cable for my camera that has the RED and BLACK wires connected to the SIGNAL and GROUND of the APM output. I have been able to get my camera to take a picture with the 3dr test script (Ch1up). That is it. It doesn't run the different functions even when mavlink shows the output to be 1100, 1500, 1900 etc... I know I am outputting a signal from RC_6. The script does not seem to respond to changes in the PWM signal, it only responds erratically to the PWM signal by invoking the CH1up function. Here is my question:
Can the CHDK firmware read PWM output directly? I cannot find a definitive answer to this anywhere. Some threads claim that there needs to be an intermediary switch/arduino to "translate" the PWM into readable voltage. Others claim it is possible through only the PWM signal directly into the camera. I just want to get an answer to this (I want to know if the cable i'm using can even distinguish between PWM positions before I rip my hair out trying to make it work). I have scoured the copter and plane CHDK tutorials. One uses the gentwire USB2 (and seems to indicate it is needed) while the other uses the simple red(positive) to signal, ground to ground method.
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No, CHDK can need read PWM natively. It either needs a translator board, like gentwire, or the digital pins on the flight controller need to send high/low signals (not PWM) that CHDK can read, which is what Pixhawk does.
Thank you! If someone high up reads this thread please just put the above sentence in the CHDK tutorial about the wire, it will save people a ton of time!
Do you have a link to the tutorial you're referring to? There are a lot of them!
http://copter.ardupilot.com/wiki/common-apm-to-chdk-camera-link-tut...
this is the one with the simple wire - i am not sure if this still works with current APM settings or not. I was confused because after reading the tutorial above then I read this one:
http://copter.ardupilot.com/wiki/common-chdk-camera-control-tutorial/
and this one
http://plane.ardupilot.com/wiki/common-chdk-camera-control-tutorial/
and it has an explanation about what the CHDK cable does (translate pwm to signal voltage), but doesn't say that the simple kind of cable doesn't do that! I feel dumb now but that is where I went off track - I was thinking my red and black wire connection would somehow translate it. I was actually thinking it happened within the APM before it sent the output signal.
Is it possible for the APM to send a non-PWM signal to the output?
I have a question about these tutorials. I have not had luck getting my camera to respond accordingly on the second two tutorials, but have can the camera to respond using the simplified cable and method used in the first tutorial. This one: http://copter.ardupilot.com/wiki/common-apm-to-chdk-camera-link-tut...
My question. Now that I can get the camera to respond after traveling a certain distance, what changes can I make to get the camera to respond to the APM and take pictures at waypoints?
Thank you.
Ah, those are for APM. That's a 5v board and I think the difference between those two sets of instructions is that one without the special cable was written after the APM software was enhanced to automatically create the correct signals for CHDK (not PWM). So I guess it's fair to say that the second two instructions are for generic CHDK use on any channel, while the first one is an optimized use of CHDK on one specific pin that has now been modified by the code to not need a special cable.
In short, both can work.
Please note the newer Pixhawk autopilot is a 3v controller, and it needs a special cable to do the voltage conversion.
Thanks for the info - can you clarify if it is only the camera shutter RELAY pin that will send the modified pwm->voltage or will it also send it if I set up the CAM parameters for SERVO pin?