Has ANY ONE switched from APM 2.6 to Pixhawk? If So

I’m planning to change the controller in my 2 QUADS from APM 2.6 to Pixhawk. What do I have to pay attention to? What are the caveats?

If you are one of the people who may have made the Jump from APM 2.6 to PixHawk 2.4? Would you mind Describing how it went for you? what problems you had? what did you get in the PixHawk Package? how does Control & Handling Change from APM 2.6?

If there is a Thread/Video that Covers this already, please link me?

if there isnt a Video, i’d like to get enough information to make one as i already have 2 X650 XAircrafts that i could use as comparisons.

thanks in Advance

Yep,I’m in the process of switching over.

No real drama so far, but I need a cable for my Xbee pro and a cable for my 3DR Lea6 Gps V1.1

Looks like the existing power cable from the APM 3dr power module will fit fine.

Does anyone know if these exist or do I really have to buy a new GPS/Mag

Check the 3DR store? you might find the cable there?

Those cables are fairly easy to make yourself with parts from the 3DR store or from eBay. I made quick’n’dirty cables for my old style 3DR telemetry radios from micro-JST pigtails (fit the Pixhawk’s DF13 perfectly) from eBay which I had flying around.

Are these cables not acceptable for the Pixhawk ? store.3drobotics.com/products/d … ctor-30-cm

Jeps they are but you still need the other side for a GPS or old style radio :slight_smile:. That’s what I meant with “parts from the 3DR store or eBay”. You can use such a cable, cut it in half and put a suitable plug to the open end. I just used the Micro JST because I had them flying around here.

On the cable thing… this is going to be a point of confusion for many folks potentially. There are some obtuse references to cabling spread about in different places. Electrcal engineering minds probably have no trouble seeking out the wiring schematics and figuring it out. Other’s… maybe not so easy. 3DR or anyone care to add a “how to” somewhere? Telling someone how is one thing. Showing them how is much better for some folks.

I see reference already from the more cynical minds on the forums that this is just another marketing ploy to sell more 3dr radios and gps units.

So far what i have been told by 3DR tech Support on a phone conversation that All Cables from APM 2.6 will connect to the pixhawk with the Exception of the Telemetry cable which can be gotten if you bought a 3DR Newer telemetry kit (the Ones with the protective case) or you can purchase a 6 to 6 pin wire for 3.00 from 3DR.

Pixhawk is very very NEW as far as 3DR’s focus so there is little to go on as far as diagrams or videos. there is documentation in the Adrupilot/Arducopter wiki but it is quite technical in nature but it also isnt hard to follow.

It reminds me of the early days of Mikrokopter trying to understand how to install Pixhawk - lots of googling (thankfully not having to use Google Translate) and looking at circuit diagrams to find out how to connect it all and check signal order on connectors.

I found my MTK and Ublox GPS would not connect straight into the Pixhawk as the connectors are not the same. There is a cable available from 3DR I believe. I have also had to make up a Telemetry cable to connect to my Xbee. A diagram showing the signal on each pin of each connector would have saved me a lot of time. It seems that 3DR are aiming at more of a plug ‘n’ play solution than catering for tinkerers/hackers like me.

I would much prefer that the very small JST (or similar) connectors were not used as I have found the wires fracture close to the connector - I tend to hot glue the wiring to the connector.

Once the Pixhawk is connected then it seems to look and feel like an APM - but I have not yet flown my Octo with it.


thanks for the answer peter

Someone at DIYdrones forums posted that as well.

But this seems not be true,

as far as the already published PX4FMUv2.3 (PIXHAWK) schematics are correct :

  1. The PIXHAWK GPS Port pin assignment (Serial 3 at sheet 2/12) differs from (so called) old and new style GPS Port of the APM 2.5 / 2.6

  2. The PIXHAWK Compass port (I2C at sheet 4/12 ) offers at PIN1 5V instead of 3.3V as the APM does, which means, that if you are using the old 3DR Compass BOB with 3.3V PAD (DEFAULT) soldered , you might fry it.

So you better carefully compare the schematics first, before you connect any peripherals. I did a picture for my own orientation, I cant post here due to picture size limitation of this forum , but its easy to extract the connector pinouts out of the schematics.




PS: Maybe …I´m wrong as well, but since this is the 3DR support forum , I am sure, somebody will check this.

According to Randy McKay, lead developer of Ardu Copter, on DIYDRONES he posted this response tothe 5V question

All the Serial ports are 3.3V but also 5V compliant. So I guess they’d like to receive 3.3V but they’ll be totally fine with 5V.

the Conversation Is here
diydrones.com/forum/topics/a … 5#comments

You missunderstood the issue. , the linked discussion has nothing to do with the voltage supplied at Pin1 of the I2C port.

Some compass BOB, like the mentioned 3DR Board with 3.3V Pad soldered by default are not able to handle 5V , the PIXHAWK provides at PIN1 of the I2C port (This is not one of the serial ports)

Summary (if the schematics are correct) : If you switch from APM 2.6 to PIXHAWK, the Telemetry cable is not the only thing to take care of, the GPS cable has to be rearranged /switched as well, and it is necessary to check, if the compass BOB (or onboard compass) is able to handle 5V . Sometimes a pad has to be resoldered , and 3.3V only BOB (without onboard regulator) can´t be used anymore .

If you use RSSI, there is another thing to figure out. Through obscure and circuitous means, I found the physical pin to attach to but good luck on finding the pin number in MP. Someone has said this feature isn’t fully implemented yet. :open_mouth: :imp: It’s beyond me how a product that would be used for long range flying would not have the RSSI laying flat.

Inputting the receiver RSSI is not implemented in the PX4 firmware yet, just a heads up.

Hi mlapaglia,
How are you aware of this? I’ve asked on forums and every where I can think of and have not got an answer. I suspected as much though. So much for and I quote, “PX4 and 3D Robotics present Pixhawk: An Advanced, User-Friendly Autopilot”
To fly long distance without RSSI is a fools game. SBUS out is the same pin as RSSI in. Soooo, it needs to be set for the function on the Pixhawk and the pin assignment in MP. Relegating this to a low priority is quite disappointing.

From here:

Ha, ha. That’s another post I made on the same subject. Very sad they chose to release the Pixhawk without something as fundamental as RSSI implemented. I was trying to get a more definitive answer.

[quote=“Steven G”]Ha, ha. That’s another post I made on the same subject. Very sad they chose to release the Pixhawk without something as fundamental as RSSI implemented. I was trying to get a more definitive answer.

Not a problem, most advanced users don’t care about RSSI. I could not imagine to fly VLOS og BLOS, caring about one simple RSSI information. If you push the limits of the radio, you should not depend on it.

You’re joking, right? U must fly the same place every day in a perfect, non-polluted RF environment.
Then u have to as why every OSD on the market and every LRS has RSSI. Advanced user, indeed.