ArduCopter User Group

Discussion group for ArduCopter users

Members: 2764
Latest Activity: yesterday

Discussion Forum

Custom Autopilot development - Theory through Implementation

Started by Wil Selby. Last reply by Stone1295 yesterday. 2 Replies

I started this project wanting to learn more about the ArduCopter software that was powering my APM board and 3DR Quad-C frame. I found …Continue

Tags: equations of motion, MATLAB, autopilot, Control System, ArduCopter

GPS err in altitude vs. flying a drone at low altitute 3 mts

Started by Darius Jack on Monday. 0 Replies

Hi,I would like to study GPS err in altitude,since Cala suggested problems flying a drone at 3 mts altitude in agriculture.Laser Developer offers Lidar technology solution.Let me know your  opinion…Continue

Motor spin slow than others

Started by Cristian Rougier. Last reply by Khoa Vu on Monday. 19 Replies

Hello, all , im working with APM 2.5, in X configuration, when i arm the APM, one motor (motor 4) spin slow than others 3.When i calibrate the ESC's in automatic mode, all spin with same speed and…Continue

Noob APM/PixHawk RC transmitter coming soon to HobbyKing

Started by Tony Kenward. Last reply by Khoa Vu on Monday. 3 Replies

I am not interested in purchasing one of these, but I thought y'all may be interested. [Chinglish description text spell-corrected and posted below]--------------------------------------The Quanum i8…Continue

Comment Wall


You need to be a member of ArduCopter User Group to add comments!

Comment by Sean Headrick on May 20, 2014 at 8:46pm

I am a bit new to it, but I am triggering a couple cannon cameras with the CHDK USB connected to the with a turnigy Rx switch. All i am looking for is a high PWM signal. It seems like it shouldn't be this hard. I think I just have some servo or PWM limits out of wack.

Comment by Randy on May 20, 2014 at 7:52pm


    I guess you're triggering "cameras" not "cannons"!  In any case, it may be because the update rate on the pins on the back of the APM are running at 490hz while RC10 and 11 only run at 50hz.  It's likely the servo or whatever that is attached to the pins that can't handle the high update rate.

Comment by Artem on May 20, 2014 at 5:44pm

ok, maybe everyone now this and it is an obvious thing but here is what I just figured out:  the "noisiness" of your 5v source to the FC will affect the number of sats your GPS will find!  In about February I upgraded my copter to 6s and because 3dr doesn't carry a 6s PM I got myself an eBay version which supports up to 30v and provides V, I and 5.2v for up to 3amps. Since it was only 15usd I honestly didn't hope it would work right away, but surprisingly it worked right out of the box!  Voltage and Amps readings on APM were extensively bench tested with a borrowed watt meter and my multimeter to confirm their worthiness. Everything checked out good, in fact I was very happy, I didn't even need to adjust anything in MP, I just chose 3dr power module and I had m volts amps correctly comprehended by APM.  around that time I had minor crash in which I though I damaged my 3dr GPS/MAG combo, so the sats were never higher than 11 and that happened only after 5-6 minutes sitting in the open field. since it was flyable and I consistently was getting 11 sats + 1.6-1.8 hdop, I didn't bother to replace it. So here is the culmination:  Last weekend I got a new 3dr gps/mag from a friend of mine and put it on the copter, again 11 sats and no more! I started experimenting with the shielding, but doesn't matter what I tried I still had 11 Sats, that's it.  Finally I switched my attention to my friend's copter to see what was different... the first thing that standed out was that he runs 4s, I took his battery plugged in to my copter.... still 11 sats! ok, the only thing different among our builds left was PM. I took my old 3dr pm, soldered it onto the available leads of my PD board and hooked up a 4s batt, right away I got 13 sats and that number went to 14 in about 2 mins.  that is w/o ANY shielding of GPS... I went back to my 6s ebay PM, took the gnd/vcc wires and put them through an FPV LC-filter. hooray 14sats in under a minute from cold start (due to lack of time the operations took place on different days). now I have at least 9 sats inside the garage with garage door closed, no windows and a second story on-top. 

just my .02

Comment by Sean Headrick on May 20, 2014 at 5:14pm

Some help please! I have been trying to get two cannons to fire simultaneously while being stabilized by two servo driven gimbals running off pins RC10 and RC11. 

When using 10 or 11 to trigger the cameras works those seem to be the only pins that drive the servos. I have tried multiple times to get RC8,7, just about everything I can

 think of but I seem to be missing something. I am using channel

 7 as my manual camera trigger and have set the servo out function of RC8 to "camera trigger" I am really at a loss. If anyone could point me in the right direction I would sure appreciate it.  

Comment by Andre Schoonbee on April 22, 2014 at 1:37pm

I have another basic question:

What is the significant difference between professional autopilot systems and opensource units. IS it really worth the extra money or will opensource units be able to provide the same functionality such as blackbox, phone or tablet comms or even joystick from ground station control?

Comment by Shyam Balasubramanian on April 22, 2014 at 1:10pm

@Andre Schoonbee : I think this is a great idea :)

I am sure, such a mode like "Point of No return" will give more versatility to Arducopter code base and probably, save some folks their copters!

Comment by Andre Schoonbee on April 22, 2014 at 1:00pm

I have an idea/request

I believe it will be of great help if we could have a mode like "Point of No Return". The idea is that the autopilot needs to monitor the battery usage as well as the distance from home and work out the consumption of power. Then given the amount of battery power still left it should initiate return to home. This will prevent loss of the unit. TI have this as a mode will give the user the ability to select this if they are flying over difficult terrain or over water.

Comment by Artem on April 20, 2014 at 7:12pm

Hi, I am trying to pair 2 air modules of an old 3dr radios, does anyone know how to accomplish this?  

Comment by Thomas J Coyle III on April 19, 2014 at 4:11pm


The PM Eagle files are on this webpage:PM


TCIII Admin 

Comment by Longshot7601 on April 19, 2014 at 3:37pm

Does anybody have a link to the Power Module schematic?  Mine isn't working and I want to know why.

Thanks in advance.


DIY Drones Monthly


Season Two of the Trust Time Trial (T3) Contest 
A list of all T3 contests is here. The current round, the Pylon Race, is here

© 2015   Created by Chris Anderson.   Powered by

Badges  |  Report an Issue  |  Terms of Service