Multiwii 2.4 - Tricopter - How to activate yaw servo?

[Vgsjovik]

Hi!
I'm a multiwii-beginner and I am assembling a "2.0" version of my tricopter. Last year I used a FyeTech FY-901 FC, but I wanted something with more options so I bought a Crius AIO Pro 2.0 card.

I have hooked up all the electronics, and it seems to be working fine. All except the yaw servo. I can't seem to get a "servo signal" on any of the pins. Do you have any tips?

I can't any updated wire-diagram for MW 2.4. I have seen that pin 3 is often used for the yaw servo, but it does not work (for me). Any suggestions?


Here is a picture of my board.

 

[RichB]

Do you have the board programmed with tricopter version of the firmware?

 

[Vgsjovik]

Yes I have.
I have also tried different boards from the list. (Not just the Crius_aio_pro). A lot of them seem to work with my board.

Is there a way to see which pin goes to which ESC (motor) in the code?

This is from an older version:

FRONTMOTORPIN 2 (on 328p was 3) = servo for tricopter
REARMOTORPIN 3 (on 328p was 9)
RIGHTMOTORPIN 5 (on 328p was 10)
LEFTMOTORPIN 6 (on 328p was 11)

Is the servo still on pin 3 in version 2.4?

UPDATE: Of course, I have tried to use pin 3, but no luck. I have tried all pins and there is no servo-respons.

 

[Craftydan]

Have you tried any of the motor connections to see if they can get an ESC to respond?

Fundamentally, it's the same type of command, except the servo's neutral is around the middle of it's range at 1500us, and the ESC's neutral is around the bottom of it's range at 1100us.

 

[Vgsjovik]

The ESCs are working, but there is no respons when I plug in the servo. Maybe it's broken or burned..

I will tinker some more =) Thank you for getting back to me!

Another thing: When I arm the board, the motors start automatically, even though the throttle is all the way down.
(Throttle is not reversed). I have defined the ESCs to be SimonK (I am using Afro Slim ESCs).

Are they supposed to do that?

Should I alter som settings? Here is what I use now:

#define MINTHROTTLE 1064 // special ESC (simonk)
//#define MINTHROTTLE 1050 // for brushed ESCs like ladybird
//#define MINTHROTTLE 1150 // (*) (**)

/**************************** Motor maxthrottle *******************************/
/* this is the maximum value for the ESCs at full power, this value can be increased up to 2000 */
#define MAXTHROTTLE 1950

/**************************** Mincommand *******************************/
/* this is the value for the ESCs when they are not armed
in some cases, this value must be lowered down to 900 for some specific ESCs, otherwise they failed to initiate */
#define MINCOMMAND 900


Throttle input is 975 when it's all the way down.

 

[makattack]

You will have to uncomment this in config.h to stop the motors when armed as follows:

    /* motors will not spin when the throttle command is in low position
       this is an alternative method to stop immediately the motors */
    #define MOTOR_STOP

Yeah, I would test that servo with a tester or just connected directly to a receiver...

 

[Vgsjovik]

The servo works fine when connected to the Rx. I just tried it.

Also, I've figured out that the signal on pin 2 is the servo signal. An ESC can use this signal and it responds when I move the board, as a servo would.

But when i connect the servo it is "dead" not even a little twitch.
Weird...

 

[Vgsjovik]

Finally figured it out!
It was no power from the pins. I connected the power to another ESC/servo-port. (It was not recommended)

I had power in on "5V input power".

Thank you for responding!

 

[makattack]

Ah yes, it's usually the simple stuff we overlook. Yeah, if you're using "opto" ESC's, you will need to supply power to the servo rail for a tricopter.