# Some questions about CCPM.main.mix

**URL:** <https://discuss.px4.io/t/some-questions-about-ccpm-main-mix/8198>\
**Category:** Uncategorized\
**Created:** [October 22, 2018, 7:19am UTC](https://discuss.px4.io/t/some-questions-about-ccpm-main-mix/8198 "2018-10-22T07:19:32Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![L3Y1Q2](https://discuss.px4.io/user_avatar/discuss.px4.io/l3y1q2/32/2112_2.png) [@L3Y1Q2](https://discuss.px4.io/u/L3Y1Q2)\
**Post date:** [October 22, 2018, 7:19am UTC](https://discuss.px4.io/t/some-questions-about-ccpm-main-mix/8198/1 "2018-10-22T07:19:32Z")

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Hi, everyone  
I have some questions about the CCPM.main.mix .

1. Output 4 - Motor speed mixer  
Dose is only control the motor speed ? Or it also control the Collective?  
What index to use here? 4? Why?
2. What is the difference between the CCPM.main.mix and blade 130.main.mix? except the angle.

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**Author:** ![Bart](https://discuss.px4.io/letter_avatar_proxy/v4/letter/b/f19dbf/32.png) [@Bart](https://discuss.px4.io/u/Bart)\
**Post date:** [October 22, 2018, 11:58am UTC](https://discuss.px4.io/t/some-questions-about-ccpm-main-mix/8198/2 "2018-10-22T11:58:11Z")

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CPPM uses a separate channel (4) for throttle. This is separated from collective pitch.

blade 130 uses a throttle and collective curve, both linked channel 3

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**Author:** ![L3Y1Q2](https://discuss.px4.io/user_avatar/discuss.px4.io/l3y1q2/32/2112_2.png) [@L3Y1Q2](https://discuss.px4.io/u/L3Y1Q2)\
**Post date:** [October 22, 2018, 12:48pm UTC](https://discuss.px4.io/t/some-questions-about-ccpm-main-mix/8198/3 "2018-10-22T12:48:57Z")

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Bart, thank you for your reply.  
In your words, CCPM uses channel(0,1,2) control the attitude and collective pitch? channel(4) just control the throttle ( Motor speed )?  
In addition, where does the control input of channel 4 come from? I just find the control input of channel 0 ,1 ,2 in Firmware\src\modules\mc\_att\_control\mc\_att\_control\_main.cpp.  
If you know ,please tell me, thank you very much.

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**Author:** ![Bart](https://discuss.px4.io/letter_avatar_proxy/v4/letter/b/f19dbf/32.png) [@Bart](https://discuss.px4.io/u/Bart)\
**Post date:** [October 22, 2018, 2:13pm UTC](https://discuss.px4.io/t/some-questions-about-ccpm-main-mix/8198/4 "2018-10-22T14:13:18Z")

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I think if you configure a rotary knob or a switch as flaps. See [http://dev.px4.io/en/concept/mixing.html](http://dev.px4.io/en/concept/mixing.html). I didn’t check in the code.

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**Author:** ![L3Y1Q2](https://discuss.px4.io/user_avatar/discuss.px4.io/l3y1q2/32/2112_2.png) [@L3Y1Q2](https://discuss.px4.io/u/L3Y1Q2)\
**Post date:** [October 23, 2018, 1:05am UTC](https://discuss.px4.io/t/some-questions-about-ccpm-main-mix/8198/5 "2018-10-23T01:05:18Z")

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OK，Bart.  
I used the engine speed as flaps before, but I am worried that there is already flaps in other places where I didn’t notice.  
Thank you for your reply.