Paul René Jørgensen

I just wanted to let you know about todays progress. The GPS module landed in the mailbox this morning, but I forced myself not to rush and wire it up to the Spot right away. I know that this GPS module is compatible with the Spot so there was no reason to rush it.

What I was more concerned with was the enable/disable switch and the rudder pass through signal. I started out wiring up the RC receiver to the spot and wrote some lines of code to get the pulse length of a signal connected to one of the Dx pins of the Spot.

    private int getRCPulse() {
        EDemoBoard edb = EDemoBoard.getInstance();
        IInputPin pin = edb.getIOPins()[EDemoBoard.D3];
        return edb.getPulse(pin, true, 30);
    }

These few lines of code should give me the length of the pulse coming in on the D3 pin every 30 ms measured in microseconds. And guess what happened when I connected the battery? It worked!!

Next up was to prototype the rudder servo pass through. I added some more wires to the Spot connecting the servo signal cable to one of the Hx pins and made sure the servo was powered by the RC receiver.

        Servo s = new Servo(EDemoBoard.getInstance().getOutputPins()[EDemoBoard.H1]);
        while(true) {
            int l = getRCPulse();
            s.setValue(l);
            System.out.println(l);
            Utils.sleep(1);
        }

This code reads the rudder RC channel and passes the value on to the connected servo. Amazing as it sounds, but it actually works!

I now have a spot decoding the RC receiver signal and later outputting it to a connected servo, passing it through the spot as if it was not there! This is what is supposed to happen when the autopilot is disabled. When I hit the gear switch on my transmitter the autopilot logics should kick in. But that is another story..

Aerial photography (AP) from radio controlled (RC) airplanes is one of my hobbies and I always seek to increase my toolbox and expand my operating radius. The other day I was browsing the shelfs at my local hardware store when I walked past this UHF antenna.

It immediately catched my eye and my brain started visualizing a how this pile of aluminum pieces could fit together creating a airplane. It was constructed from 2 long square tubed aluminum rods joined by a bracket. It would greatly simplify transportation if I could detach the 2 rods when driving to and from locations.

I did not use all the parts from the antenna as I needed only 2 “cross over” bars to work as a base to put the wing on. I could even remove the metal parts of them and leave only the black plastic pieces, but as I’ve overpowered this plane I ain’t too afraid of a little excess weight.

I removed the electronics from the connection box and fastened a carbon fiber landing gear. I can now easily fasten it to the aluminum rod and move it forward or backward depending on my load. Putting everything together from the antenna and landing gear I get this.

I then started on the elevator and rudder construction. I scaled the template for the Beasts/Solution (by Mike “Power”) to about 70% and dropped the carbon reinforcements on the lower side (I had no space for this).

Remaining work included assembling all the parts together, wire up the electronics and create a engine mount. I also had to add the servos for the elevator and rudder and cut a wing from a piece of EPS foam. If anyone is interested in how to cut their own foam wings please let me know, and I’ll consider doing a tutorial on it.

The finished plane with battery and receiver looks like this..

She had her first flight on 22. May, 2008 and it flew perfectly after some minor adjustments of the ESC and radio antenna mounts.