Clarification of power and jumper settings on APM 2.6

i am new to the APM module and am not sure on a couple of things, i have read the manual but this did not answer my questions.
I am sure they are very basic for someone in the know but for someone new i thought it best to ask.

first question.

i have the 3DR APM power module to power the APM as this was recommended. I also need to power 2 servos so need to put power onto the bus of the APM. Do i put JP1 in or leave it out to do this.

Second question.

I use Graupner radio sets and want to use the sum signal input (all signals on a single wire) from the Graupner receiver to the APM
what pin to i connect this single wire to and do i have to add any jumpers or do and bridging of solder pads on the APM ?

I wanted to ask first to clarify this before powering up the APM.

Thanks for your time



The APM PM is really not designed to support servos on the APM servo output bus. Therefore you need to remove J1 and use a BEC to power the servos on the APM servo output bus: … _Installed
This section of the Wiki explains how to connect a PPM receiver: … nd-motors/
TCIII ArduRover2 Developer

See this wiki post … -receiver/

Also you need to make sure that the graupner is outputting the channels of the PPM sum signal in AETR order that the APM encoder is expecting.

Thanks for the feedback on this, i have got the PPM sum signal working but still have a problem in that the radio is giving out mode 2 (i.e throttle on the left) but the APM is receiving this as mode 1. The opposite happens if i change to mode 1 on the transmitter. Bill Bonney i think has identified this but does anyone know how to get the APM to accept mode 2 PPM sum from the transmitter as mode 2 in the APM, i also need to work out the switch assignments next.

i appreciate any help as the APM is a new controlled to me.

Thanks again for all the help so far.

It would be easier to advise if I knew which Graupner radio you have. I did see in a HoTT manual you can modify channel mapping using Tx Output Swap. I.e. you can map Throttle (TX CH1) to be Output 3, Aileron (Tx CH2) to Output 1, you would also map Elevator (TX CH3) to be Output 2, And rudder stays the same (TX CH4 -> Output 4)
You still using your radio is Mode 1 (stick arrangement), but the PPM stream of channels (which is train on PWM values) will go from being TAER to AETR which is what the APM is expecting

Another way to thinking of the reassignment is that on the RX now you need to connect the Aileron to Servo connector 1, not Servo2 as before and etc…

The link to the manual, see page 206

Hi Bill and thanks for the reply. The radio set i have is the MC-32 and i have found out how to remap the tx outputs for channels 1 to 4 so that all works now. As soon as i fix one problem i seem to move onto the next. I am now stuck with mapping and mixing switches to get 6 different flight modes from 2 switches, 1 two way and one 3 way.
i found a link on how to do this but i cant seem to get it to work correctly, i can get 3 flight modes off the 3 position switch by combining sw 5 and sw6 under control adjust, this gives me 3 different settings but if i then try to add mix settings using a 2nd switch it all gets a bit unpredictable.

basically the problems i am having a radio config related, i have got my head around the APM but obviously i need to get the transmitter setting correct before i finalise the config and test fly. I still havnt got to the stage of configuring and assigning motor cut switch.

i use this radio set due to the telemetry and using it with the MK Mikrokopter, its a bit over the top for what i am trying to do with the APM but i dont want to have multiple radio sets.

Any help with the Graupner MC-32 setup would really be appreciated even if it is pointing me too a different forum for this radio set. I will get there but it is painfully slow.

So basically i need to set up 2 switches to give me 6 flight modes and setup a motor cut switch, that should just about get me in the air.

Thanks again for your valuable time and input

Have you seen this ?

There is also a link on that page to setup a Graupner.

Hope that helps :slight_smile:

i have sorted out a few problems today and had it flying, i seemed to have a problem with the SUM signal going into the APM, when i removed this and wired it conventionally that cleared quite a few problems but i do have a problem with the compasmot stage failing every time it keeps asking me if i have not put the throttle up to the full setting and does not give me an error reading, i am guessing this is once again back to a radio problem and the throttle cut and failsafe not being set so thats the job for tomorrow.
it surprised me how stable it is in the air even with these errors but obviously i will not be flying any distance until i get it running 100%

The link you gave me Bill does have an effect on flight mode switches but not the desired effect, its definatly in the right direction but not producing the correct results so i am going to look into this to see how it is doing it and if its a case of changing the % settings to get the correct switch operation.

Thanks for your help and if you can think of anything regarding the compasmot failure i am all ears :slight_smile: