KapV2

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Problem Statement

My original KAP board was a remote camera reciever and an MSP430 breakout board hand soldered to perfboard. It had a bidirectional limit switch, but no directional feedback. In the time that it takes to complete a full panorama on the Pentax DL (3 seconds per image when bursting RAWs) the orientation of the kite could change by tens of degrees thus creating dead-zones in the panorama. Further overlapping between exposures means more time per panorama and is not a perfect solution when the kite is moving around in the wind. Thus I wanted a controller with a digital compass that could correct for minor pointing errors and result in less dead-space in the panoramas.

Background: KAP V1

The KAP controller V1 is just an MSP430 that interfaces to the radio receiver board, a servo, and a directional momentary contact switch (single paddle with contacts on either side). The board lacks positional sensing, and as such, panoramas almost never line up due to the whole rig swinging in the wind. It would be neat to have a digital compass onboard to sense true north (and derive heading) in order to better stabilize the camera in flight.

PC Board

A PC Board was fabricated which contained (serious) mistakes which necessitated the need for greenwires. An MSP430F2132 was used, along with a 2D compass module.

MSP430 Source Code

V1 code Can be found here (For reference only, all rights reserved)

V2 code Can be found here, for what its worth. (For reference only, all rights reserved)

Results

A PID control system was attempted for the true-north pointing. Unfortunately, the 2D compass module proved useless as sensitivity to tilt was quite extreme. In a KAP setting, the entire rig could be swinging or tilting back and forth and would result in huge pointing errors. A future board will need a 3D compass module.

2010 Jasper Nance KE7PHI