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  1. #1
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    Camera Stabilization support

    Ok, I need an education.

    I'll be upfront and say I have not taken the time to go look at the data sheet.

    But was helping someone on the IRC try to get camera working and ran into the following.

    On a Mega install with 2.0 shield.

    Servo 0 - 10 are connected to mega pins 33-42

    And yet there is a note in the AeroQuad.h file that you need to jumper pin 11, 12, 13 to 34, 33, 35. I think I understand why, because the timer that is implemented in the AQ Servo class uses pins 11, 12, 13.... But here's the rub.

    12 and 13 are used heavily with LED's. And there is no mention of the LED's at all.

    So how can you have 2 pins paralleled together both with LED and potentially current limiting resistors *and* expect those pins to control PWM for a servo?

    And why on the Mega, didn't we just do timers for the 33-42 pins? Like I said, I didn't read the datasheet (maybe those pins don't support PWM (hope that's not that case or why wire them to the shield that way).

    Ok, so CupofTea or whomever, help me fill in the blanks, cuz something aint working and I"m not about to burn up a trace or hurt a processor with 2 pins in parallel with LED's etc.

    Those notes to jumper those pins just don't feel right on a Mega, and on a 328P, what do you do with the LED? and worse the software that wants to force those pins High and Low????

    Alan

  2. #2
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    Well, go figure, I answered part of my question... it seems that none of the pins that are marked servo0-9 on the 2.0 shield are PWM pins ...

    Ok, so as long as you don't configure the 33-42 pins, you can parallel them to get to the servo pins on the shield, but now how do you account for the LED?

    I've since answered part the of the LED question.. on the 1.8 shield pin 13 is the main LED (green one) and 12 is the mode LED (red one)... on the Mega, pin 13 is still the Main LED, but that is only used on the YAW servo (which most aren't using for camera stabilization). 11 and 12 are not LED pins on the Mega...
    Last edited by aadamson; 05-20-2011 at 03:22 AM.

  3. #3
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    Ok, so after working through this, I think I've figured it out.

    The Camera control will only work on the MEGA, it will not work on the 328P platform, this is because on the 1.8/1.9 shield. Pin 11 is used for Motor 4, and Pin 12 has an LED on it and is used in the software, Pin13 is even more interesting, because it has an LED on the 328 board and and LED on the shield and is also used in software and worse in the bootloader.

    However on the Mega, you can use 2 channels of camera control, because the second LED on the MEGA isn't on pin 12

    I know this is a mess, but I needed to understand it for some other work and then I was trying to help someone on the IRC get theirs working

  4. #4
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    Quote Originally Posted by aadamson View Post
    Ok, so after working through this, I think I've figured it out.

    ...snip...

    I know this is a mess, but I needed to understand it for some other work and then I was trying to help someone on the IRC get theirs working
    I can't answer the question of how it works but I can tell you that you can stop banging your head against the wall on my problem. I found that the other channels worked, jumpered around the dead header and moved to a different pin set (servo2 to servo1) and now have the channel (pitch) controlling the servo!

    Thanks for trying but this was a problem specific to my board.

    John


 

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