Has Anyone Put an APM Autopilot On an Elev-8?

GlassKNees

I am in the midst of building an Elev-8 with an APM2.5 autopilot. It will have an external compass and GPS (I'll have to disable the on-board compass). I've run into some construction issues that I think I've solved and would like to compare notes with anyone else who has attempted this mod.

GlassKNees

I have wired up my Elev-8 with the following: APM 2.6 autopilot, external GPS & magnetometer, and 900 MHZ telemetry transceiver:

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I have only one ESC BEC powering the ESC connections on the APM as well as the receiver. Also, only one receiver channel (Throttle) is powering the receiver - this was based on instructions from a YouTube video.

But I have two problems:

1. The APM won't arm

2. I downloaded the firmware on the 900 MHZ receiver that connects to my laptop, but could not connect the airside transceiver to download its firmware. Until I can do that, I cannot connect to Mission Planner on my laptop to troubleshoot the arming problem...

I tried several things to connect the airside radio and have convinced myself that it is defective, so I've ordered a new on - waiting for it to be delivered.

When I get past these problems, I should be ready to fly. The APM is configured for three flight modes: Stabilize, Loiter and RTL (Return To Launch). When I'm satisfied that these modes work well (which assumes a working GPS), I can attempt to create and fly a mission autonomously.

Duane Degn

This looks like a fun project. Do you have links to documentation about the devices you're using. I searched for "airside transceiver" but I didn't see an obvious choice on where to find information about the device.

I'd think the various parts should be testable on their own but I'm not sure about this.

Do you have a microcontroller board you're familiar with? Arduino or Propeller? I ask since I'd think there should be a way to test the transceiver with a microcontroller.

I'm very interested in your project. I hope you keep us updated with your progress.

GlassKNees

Duane, one of the biggest challenges has been the lack of documentation! Getting information has been like going on a scavenger hunt on the internet - most of my info has come from YouTube, where a number of people have produced how-to videos. When I originally contemplated this project, I thought I could simply buy the APM and swap out the Hoverfly controller on my existing Elev-8, but soon learned that the APM firmware assumes a different motor configuration. Here's what Hoverfly assumes:


And here is what APM expects:



I've also learned that when you buy components they are typically clones manufactured in China. You have to be very careful to check the wiring between them, paying attention to the pinouts to make sure signals, pwr, gnd, etc. line up correctly.

I have learned a lot along the way though. Right now, my project is on hold as I'm waiting for an USB to Serial TTL Level 5V 3.3V Adapter Module, which I need to plug the airside telemetry transceiver to my laptop so I can download some firmware that will allow 2-way communication between the aircraft and my laptop, which has a Mission Planner application installed. I need the link to Mission Planner to troubleshoot why the APM isn't arming.

I will report on progress, especially when I get it in the air. I'm looking forward to creating a mission and watching it fly autonomously!

tranger

I ran into the difference in assumed rotation between flight controllers when I swapped out my Hoverfly Open for an OpenPilot CC3D. Of course, did not find it until I tried to fly. Complete lack of yaw control was the symptom - during take-off it looked like a barber pole. Fortunately, they have a "switch all rotations" check box to avoid wiring changes. :-) (no actual rotations changed, but all assumed rotations get changed).

Good Luck with your project, I'll be lurking...

-Russ

GlassKNees

Oh, I forgot to answer your question about what controller I'm using. The APM module is the controller. If you look at the photo above it is the box with the arrow marked on it (pointing towards the front of the aircraft). The board costs roughly the same as a Hoverfly controller, but has so much more capabilities, especially if you add the external magnetometer/GPS. For example, I have programmed three modes, tied to a 3 position switch on my transmitter: Stabilize (aircraft levels out when you let go of the sticks), Loiter, and RTL (Return To Launch).

The firmware is downloaded onto the APM using the Mission Planner application which you install on your computer - you use a USB connection between the APM and your computer. Again, lots of videos on YouTube to walk you through the process.

I'm in the process of creating a Powerpoint presentation that I plan to use when I describe my project to the Sun City R/C Club. You are welcome to a copy if you'd like.

xanadu

APM will be fine on the Elev-8. Be careful with autotune and the ESC compatibility issues. Arducotper default PIDs are okay to start off with a quad that size too. You're lucky, the Elev-8 frame is nice and open with lots of mounting points.

GlassKNees

Thank you for the advice - more stuff for me to learn about! I hope that in the next few days to get the telemetry link working and I can troubleshoot the APM arming issue. I will then explore doing autotune. I'm not sure I have a compatibility issue with the ESCs - will have to research that.

Thanks again!

Brian

GlassKNees

I just returned from a two week vacation and thought I'd post an update. I managed to get my 915 mhz telemetry link between the aircraft and a laptop running Mission Planner. I found a "motor test" function and when I tried it I found two motors would not spin. Upon examination of the wiring, I found a bad solder connection which I fixed. But I could not get the #2 motor to work at all. I removed the boom and hooked up the wires to a spare ESC and plugged the ESC control into the throttle channel of a spare receiver and was able to command the motor to run. I put the aircraft back together and verified that the wiring going all the way from the motor to the APM is okay, but still no joy....
I began to suspect the APM itself was faulty and was ready to abandon it and get a Pixhawk flight controller, but decided to tear down the aircraft one last time to look for a bad wire or something. Then I discovered a wire going from the APM power module to the APM had come loose and separated from the connector. Upon examining the connector I noticed a second wire was also loose and the connector is damaged. I don't have a spare and no tools to make a repair, so I ordered a replacement power module from Amazon (no, it wasn't on sale during their big event yesterday),  and  I hope to get it in a couple of days.
Meanwhile, I found and fixed two solder connection problems on my other Elev-8 but I'm waiting on some new screws to arrive - there are a couple that were bent during a crash and need replacement and I had no spares. The hardware should arrive tomorrow and so I'm hoping that both aircraft will be ready to fly by this weekend.

Publison

Gosh,
Seems like Murphy is stalking you!
Too many bad luck scenarios. Hope you get at least one up and running this weekend.

GlassKNees

Thanks! Yeah, I've had quite a bad streak, but much was self-imposed - I need to be much more careful when soldering! But I've learned a lot, and I guess that's the most important thing!

GlassKNees

I'm happy to report that my APM ship is ready for it's maiden flight! After installing the 3DR APM 2.6 module, going through the firmware install, calibrations, etc. The ship armed the first time and all four motors spin!

So now I have a ton of work to do - test fly it and make sure that all controls are working and it flies as expected. I will have to go through some tuning so I have a lot more yet to learn but I'm happy to have finally busted through the problem that was holding me back so long. So, my theory that the Chinese clone APM module was defective seems to have been correct.

I now have both aircraft ready to fly!

NikosG

tranger wrote: »

I ran into the difference in assumed rotation between flight controllers when I swapped out my Hoverfly Open for an OpenPilot CC3D. Of course, did not find it until I tried to fly. Complete lack of yaw control was the symptom - during take-off it looked like a barber pole. Fortunately, they have a "switch all rotations" check box to avoid wiring changes. :-) (no actual rotations changed, but all assumed rotations get changed).

Good Luck with your project, I'll be lurking...

-Russ

tranger,

OpenPilot seems to be a verry interesting and cheap choice for autonomous flight. Have you any more information about the combination elev-8 and OpenPilot CC3D?

GlassKNees

I have bad news and good news. First the bad:

During a test flight, I lost my quad in a flyaway. I tried out Loiter mode and it drifted away to the northeast and climbed. My attempts to bring it back failed and in a panic I hit RTL which did not work. The last I saw it disappeared over some trees at the edge of the driving range where I was flying. This occurred Aug 9. For several days I searched the area with no luck. I even attached a video cam on my other Elev-8 and flew it over the trees to see if I could spot it hung up in the branches - no joy.

I wrote it off after a couple of weeks and decided to embark on a new project: a Tarot FY680 Pro hexacopter. I bought the frame kit, motors, ESCs, a new APM 2.6 and external GPS/magnetometer and props; I've started building the aircraft.

Then, Sunday evening (9/13), I was on the Sun City Neighborhood website and perused the message boards and discovered a post under Lost and Found - my quad had crashed landed in back yard. I notified the guy and he still had it, so I went right over to his house. Sad to say, it was in a small pile. The guy left the aircraft in his year for some unknown period of time and then his 12 year old grandson came to visit and pulled the wires off the telemetry transceiver, GPS and magnetometer. One boom was bent slightly and it's motor mount was broken and the motor trashed.

I pretty much took it apart and found that the other booms are okay as well as the motors and mounts. The APM appeared functional as I could re-flash the firmware and go through the Accel configuration, but could not do the magnetometer configuration (I used a new GPS/mag antenna that I bought for the Tarot ship) - a close examination of the socket revealed that its cracked and the pins are bent, so I've decided to junk it and get a new one.

I've ordered a new boom and hardware pack (screws, bolts) to replace a couple of bent screws. I will used the APM, GPS and magnetometer that I bought for the Tarot aircraft, as I'm in the early stages of construction and won't need those items for awhile. I also ordered a new telemetry transceiver in case the one I have is nonfunctional. With luck, I should have my APM Elev-8 back together in a couple of weeks.

Once I'm ready to fly, I will conduct a rigorous and more conservative flight test program - I will use a laptop in the field with Mission Planner so I can monitor things (my wife will monitor M.P. for me while I fly); I may try to tether it somehow until I'm satisfied that Loiter, Alt Hold and RTL flight modes work.

Meanwhile, I've got my other Elev-8 to practice with and the Tarot build to keep me occupied.

BB

GlassKNees

I have completed the repairs of my APM Elev-8 - here it is:



Here is a picture of both of my Elev-8's:

GlassKNees

I have flown my Elev-8 with the APM flight controller/autopilot for awhile now and I'm really happy with the results. Flying using the Stabilize flight mode is a pleasure, especially in breezy conditions. The aircraft is very stable and no PID adjustments were required. Alt Hold and Loiter modes work well. Right now, I'm having problems with my Spectrum transmitter and had to send it to Hobby King for a checkout. When I get it back, I plan to test RTL and then try loading a mission and fly it autonomously. If anyone is interested in building an Elev-8 like this, here is the list of parts I used along with prices - note, Parallax has cut the price of the Elev-8 V2 kit by $150 to make way for the upcoming V3.

Elev-8 kit $400
3DR APM 2.6 autopilot $100
APM Power Module $25
3DR GPS w/Compass $90
Foldable GPS mast $8
Spektrum AR610 Receiver $50
915 Mhz telemetry transceivers $24
APM Vibration Dampener Platform $7

Total cost is $704, excluding shipping costs

The Mission Planner application is a free download and it's packed with functionality. I think you would be hard pressed to find a quad that offers the same capabilities as this for the price.

Publison

Thanks for the update!

Need videos!

GlassKNees

I had a successful test yesterday of a waypoint mission. I had four waypoints as well as home. At waypoints 2 & 3 I had the copter circle once. Upon returning home it landed itself - all went without a hitch. MY wife and I monitored the flight on Mission Planner from our patio.

https://youtu.be/KLAaMcwmW-Y

LoopyByteloose

Very nice. I enjoyed the video with music.

Publison

Most excellant! Airwolf soundtrack was appropriate.

GlassKNees

Thanks guys! It was a lot of fun putting the video together. I've got a lot to learn about waypoint missions, but at least I have a working platform! I'm working on a Tarot hexacopter that has a 2 axis gimbal & Go Pro camera - plan to use what I've learned with my Elev-8 on the Tarot.

NikosG

Publison wrote: »

Most excellant! Airwolf soundtrack was appropriate.

The soundrack choice "For A Few Dollars More (Theme by Ennio Morricone)" was excellent as the video!!!
Congratulations ClassKNees!!!

Bigs9981

GlassKNees - This is a great post and exactly what I have been looking for. As you mentioned above finding information on various projects related to the Elev-8 is not easy! I will be getting my Elev-8 V3 this week and plan to add GPS & live video (I don't plan on getting carried away with flight distances). Should be a fun project with my two boys

The parts list you posted is great and I have already started looking at components. At one point you mentioned putting together a power point... The link to the YouTube video you created is also not working. Do you have any more information? I will take whatever you are willing to provide - sample codes, etc...

Thank you in advance!
Bigs

Publison

Bigs9981 wrote: »

GlassKNees - This is a great post and exactly what I have been looking for. As you mentioned above finding information on various projects related to the Elev-8 is not easy! I will be getting my Elev-8 V3 this week and plan to add GPS & live video (I don't plan on getting carried away with flight distances). Should be a fun project with my two boys

The parts list you posted is great and I have already started looking at components. At one point you mentioned putting together a power point... The link to the YouTube video you created is also not working. Do you have any more information? I will take whatever you are willing to provide - sample codes, etc...

Thank you in advance!
Bigs

Welcome to the forums!

You may also like to follow along on this thread:

http://forums.parallax.com/discussion/comment/1395796/#Comment_1395796

GlassKNees

Sorry for the late response! I have loads of info and experience now. I have retrofitted my first Elev-8 with an APM and it flies great! Currently I'm completing a 3rd Elev-8 made from spare parts and other parts salvaged from a crashed TArot hexcopter as well as some new components.

I will put together a PowerPoint and post in the next day or so.

Again, sorry for the delay!