My spanking new APM 2.5 arrived earlier this week, along with the xBlo GPS and 3DR radio modems. We've flown the X8 previously on RC just to make sure servo travels and CG are all good to go, but yesterday we conducted a series of 10 minute flights with varying levels of automation.
Note that we have not installed the Pitot sensor as yet, all flights we conducted with GPS/Alt/Accel guidance only, we didn't change anything in terms of PID's or settings out of the box whatsoever.
The whole process was;
1) Take it out of the box and go oooo, ahhhh, shiny.
2) Make up some leads and sort out power for servo rail and APM - Note that on APM2.5 there is a jumper on the output rail for the servos / equipment that is supposed to (when bridged) provide power from the input side to the output side. I found that mine had no voltage whatsoever with the jumper installed or removed. Therefore I decided to power the output rail (servos etc.) from the BEC in my speed controller. Which, actually, makes more sense than sinking current from the power supply for the APM / Rx.
3) Update code on APM to latest and greatest via USB.
4) Follow quick setup guides on website to configure airframe etc.
5) Tear some hair out trying to get radio modems to work then realise that if you don't supply exactly 5V to the input side then the radio modems won't work - derrr.
6) Get radio modems up and working test telemetry and confirm orientation of APM.
7) Remove propellor from A/C. - IMPORTANT.
8) Calibrate radio control and confirm flight modes via mode switch.
9) Set stablise mode and confirm direction of control surfaces is correct by rolling and pitching airframe.
10) Set RTL mode (NOTE Propeller is removed) to confirm everything again including throttle control.
11) Charge batteries and head to the airfield.
The flights we conducted, were a series of 10 minute flights to explore each of the capabilities of the APM;
Flight 1 - Testing stabilise mode and rudimentary RTL.
- Flight in manual mode to confirm control
- Switched to Stablise mode from level flight to confirm everything is ok there
- Back to manual mode and placed airframe in usual attitude
- Switched to stabl mode and confirmed recovery. This process was repeated a few more times to confirm everything is working as it should. No Problems.
- Flew A/C away from launch point in manual mode and then switched to RTL mode to confirm GPS tracking and control back to launch point. No Problems.
Flight 2 - Testing waypoint guidance mode.
- Program basic waypoints on Mission Planner and write to APM via radio link.
- Takeoff in manual mode, then switched to Auto and the A/C flew the waypoints no problem at all.
- Did note that in Auto and RTL mode's the throttle was a little high. Need to correct this.
- Landed manually.
Flight 3 - Testing circling, and other "advanced" features along with inflight programming.
- Program basic waypoints on Mission planner including some circling features.
- Manual takeoff, switch to Auto and the A/C flew the waypoints including circling with no problem.
- Issued "fly to here" commands - No problems.
- Issued land waypoint command - A/C started to fly what seemed like a circuit decending away from the launch point. I got a little nervous and took over. This will be out next test for flight 4 I think.
In summary, it's been a great experience. I can't believe that something so simple and cost effective can deliver such trouble free "out of the box" operation. Congratulations to everyone who has contributed to this awesome little device, and it's software. It really was great fun to put together, and my mind is bursting with ideas and applications for it.
Our next steps are to incorporate some of the things we learnt from the first few flights, and also add camera gimbal guidance from the APM along with antenna tracking at the base station.
Here's a block diagram of the current configuration.