All in one KAP control: the Wheeler/Mitchell Arduino project (pt 2)

See previous installment here

Ricoh GR f2.8 1/500s ISO 640 Bft5 KAPfoil 1.6

Ricoh GR F2.8 1/500S ISO800 Bft5 KAPfoil 1.6

Ricoh GR F2.8 1/500S ISO400 Bft5 KAPfoil1.6

A gusty Bft 5 is not a happy place for a kite: the lull to gust power variation is tough to manage and the KAPfoil swung around in the shifting flow. In these conditions autoKAP wins and I was able to turn the sequence on and off from the ground when I’d got the camera roughly where I’d hoped a subject of interest would lie. The kite movement was too great to overfly road traffic at a safe height so ths first flight with the new remote auto control would not produce the finest KAP but I would gain some knowledge as to how the programmed path ‘B’ behaves.

I tired of the fierce movements and hauled down with the auto running…

As this is the first flight of the control  code and given it was written without testing it’s a triumph- the camera movements may need smoothing but the system performs as advertised: I now have directed camera when I want and a good auto option when I need.

This completes the system and provides great flexibility. The kite flier can revert to an auto mode at any time whilst keeping the option for a directed camera. There is econnomy in switching to auto after the camera has reached the target zone. This as getting the best of both worlds as the pressures of hazard monitoring and wind variation have often killed the opportunity for directed camera work with a corresponding drop in my hit rate.


Although the Arduino processor has always had the capacity to be programmed to perform the auto functions it is not trivial to write the code and design the circuit and I am indebted to Dave Mitchell for his sterling work on this. The choice of the 8 way DIP switch to program the auto squence comes from James Gentles work on the excellent clickPan Pro device and he has been instrumental in getting Daves design working; my thanks to James for this generous help too. The openess between Kappers always impresses me!

By including an 8 way DIP switch to the circuit Dave Mitchell has added an auto mode to the Arduino based remote control.

The wiring layout has evolved:

I have chosen, as far as possible, to build to an IP65 spec as KAP is outdoor work and the controller is the first thing to hit the deck when things get messy. Working in gloves means chunky controls with surefire action are required. The slide pot for tilt is a compromise as the cost of a sealed hall effect thumbwell proved prohibitive.

Most of the space is taken up with the oversize switches on the lid.

Most of the bits are dirt cheap from RS Components or Farnell. The big expense is the Hammond 1553 case and the luxury option of buying the Pro Micro board with pre-soldered headers.

The controller needs to be tough and useable in one gloved hand. Fond as I am of steel micro switches with their positive click they all too frequently snag the line so they remain in the parts bin. It needs to be small enough to hang from a lanyard without risk of injury to it or the photographer on the run.

With care the size could be reduced further but as this is something of a proptoype the space in the case makes assembly easier:

Fortunately the Hamond 1553 case fixings are re-useable.

As the final component layout has emerged I have opted for wire wrap to board to secure the electronics as there have been many re-fits and re-builds as the design has evolved,  soldered components  have been kept to a minimum.

The programme of choice is a ‘W’ sweep with a pan at the nadir and horizon positions.

Refinements will surely follow, smoothing of the movements, better pan speed control and a 9V minature version with a USB port on the case are all in the pipeline.

Adding a simple button to the remote has increased the oportunity I have with KAP..

Dave Mitchell’s page on the Arduino cntroller is here:

and the Arduino sketch (for v1.6.4 IDE only) is here:






About billboyheritagesurvey

Heritage worker
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