APM2.5 5V/Vcc Schematic

Frequently asked questions are about powering an APM2.5 or why the same does not work or why it has failed.

Here is a simplified schematic showing the major components of the 5V/Vcc circuit on the APM2.5

Target Audience: Readers who do not have Eagle or are confused about using it.

You Need: Basic electronic schematic reading ability


Note that I have separated the PWM Output section into the upper left corner with a heavy purple line that is bridged by the jumper JP1 on the APM2.5. This is to emphasize that diode D1 passes current through JP1 (and drops voltage). The remaining energy is then called 'Vcc'.  Everything outside the purple corner is Vcc.

This is why the USB will power the APM2.5 when connected to a computer/USB hub. Note the fuse on the APM2.5 side of the USB connector AND another fuse on the output of D1. Another change from APM2.0 is the D4 6.0V Zener diode. If an over voltage is applied to the board, D4 will crowbar what it can to protect devices.

As with APM2.0, any 5V source connected to any of the indicated Vcc/5V points outside the purple corner (with GND of course) will power the APM2.5.

Also of note is the 'Mystery Port'. This port takes 5VDC before D1 and the fuse and is called 'JP_VCC'. Other clues to the mystery are the lines to 'ADC 12' and 'ADC 13'. A mystery indeed!

Any errors in this drawing from editing are mine.

I hope this can be used as reference for solving problems.



27-FEB-2014 Eagle files are now located HERE


APM2_5 Simplified Power.PNG

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      • Aaah, the power module isn't protected from powering the servo rail with the diode when JP1 is installed?

        Ok, not sure why it would be designed that way, but now that makes sense, why you'd have to remove JP1 if you use the power module.


  • hello to every one

    i'm new to this field,i'm the b'tech final year student of ECE department.

    i have taken my project up on UAV quadcopter .

    and i did all the connection process accordingly..

    i'm using x-copter configuration.i'm using APM v2.5 board.

    after setting up all these thing,while i'm get connecting to Mission Planner board what to do next ?

    Please any one help for this process....no one in my area to suggest me...and one of my friend from USA(DAVID HOTROD DETERS) he suggest me to go this forum, so on this process i'm asking you a suggestions for my project....
    • Hello and welcome.

      I suggest you work through the information in the Arducopter manual and pose questions in the forum appropriate for your software/hardware release.

      This section is specifically for questions regarding the APM 2.5 (and related) schematic.

      Good luck!


  • Hey guys, I'm looking to build an APM 2.6 with a small modification. Anyone have a Digikey BOM for the 2.5 or 2.6 by chance? 

    • Reminds me of the time someone built a VW beetle completely from the Parts Department. He had a new beetle with a Cadillac price tag! A better approach would be getting a $20 atmega2560 and going from there with the sensors. Good luck.
    • Developer
      Is this just for you? Or are you making lots of them? What modifications are you planning? Some info would be great! You can pull the BOM off the Eagle files. It's not too hard to list it out for Digikey. Though for just a few boards it will be quite expensive.

      Just remember to post your changes back here.
  • OK, I found the new location of the Eagle files.

    THIS PAGE and click on the 'Eagle files' link.

    The initial view of the board layout does not show all the traces and planes.

    You will need to tell Eagle to ratsnest the view. One member found this out when we were struggling to understand what appeared to be undocumented rail connections. We just were not enabling all the layers to be displayed.

    Look that over a while and then we can chat about details.


    I have edited my initial post to include the new location of the Eagle files.

    • Developer
      That is the correct file. The only difference with the 2.6 is we don't populate the magnetometer.
      • Craig,

        I have about 20years experience looking at CAD and multilayer PCBs.

        Not sure why you feel that 2.5 is the same as 2.6?

        Look at the 2.6 board.

        Above U3 the 3.3v regulator (APM2.5)

        U$15 Has changed chip??

        2.5 chip is not as big as the 2.6 chip??

        Next to U3 the capacitors and chip components are all in a line on the 2.6 not on the 2.5

        I don't have the Eagle files for 2.6 but the tracks seem to be different?

        IC2 has moved right by about 0.1 inch.

        The arrow for FRONT is in a different location.

        Biggest change is that I cannot find some of the surface tracks.

        The MP6000  - U5 has moved relative to U$12

        U$14 has rotated 90degrees

        The board has been re routed.

        I can sort of understand if the designer does not want copies coming from other suppliers.

        However, I am trying to fix mine!


        Maybe mine is a copy!!!!

        But I got it from UnmannedTech?

        All the best,



        • Developer
          The 2.5.2 and the 2.6 are the same. ( on the 2.6, there is no placement of the mag)
          Have a look at the picture on Randy's blog above, you will notice they are both 2.5's the sot23-5 outline reg is the 2.5v2

          Is the one you are looking at a 3DR one? And when did you get it?

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