Camera roll stabilization.

[daedalus]

Hi Tom,

Somewere in February you said "Roll stabilization of the camera is possible (1 servo output is direct
proportional with the roll angle)."
I would like to test this but where do I start?

[Tom]

I would need to add 1 additional line to the source code.

Here I added another output (servo 6) to the aileron mixing mode:

control.c

Code: Select all

      default:  // aileron
         number_of_controlled_channels = 6;
                        if (config.control.reverse_servo6)
            servo_out[5] = -(int)(sensor_data.roll*636.0) + 1500;
         else
            servo_out[5] = +-(int)(sensor_data.roll*636.0) + 1500;


Attached the hex file (untested, from development code)

Let me know how it went!

[Tom]

I forgot to tell you: this latest version (development) uses 57600 baud in gluonconfig...

Tom

[daedalus]

And it worked really well.

Thank you Tom!

[daedalus]

What I've noticed is that in Gluonconfig Configuration/Servos tab reversing the servo 6 does not change anything on the servo. Is working always in the same direction.

[Tom]

Good remark, I'll update this as well

[Vanags]

Tom, why do you need 57600 baud rate ?
1) most long range systems uses low baud rate, because of low wavelength.
2) Not everybody loves XBee as such
3) If bandwidth is high the code is not efficient, and it may eat up the CPU. (like CSV is much worse than binary packet )
4) Lost packet retransmission requires some overhead. (Some RF transceivers does it by themselves, and it requires half of the bandwidth )

[Tom]

Good questions...

1) That's true. But the baudrate can easily be changed (in code) and the telemetry rate can easily be slowed down. The actual rate is about 500 bytes per second in fast mode, or 200 bytes in slow mode. So even 2400 baud should not be a problem.So the serial baudrate should not always be the same as RF baudrate.
2) That's true, but as a developer I need to make some choices. So yes, it's currently optimized for XBee.
3) Also true... But the code is quite modular, so for example MAVlink is easy to implement.
4) Yes, currently there is no packet retransmission.

[Vanags]

Tom, thanks for explanation! 500bps is absolutely OK.

[daedalus]

Tom, I still want to reverse the direction of the servo 6.
I there a way to generally modify a variable if it's not on the GluonConfig interface?
Some command line?