Pixhawk high voltage setup help

Hi, I am new to the forum and I am jumping in with both feet with the new Pixhawk. I have purchased the controller with the 915mhz data link from 3D Robotics

My goal is to apply some all of the current Quadcopter features to a traditional heli. I am an experienced heli 3D pilot, and I have resisted the easy way out by purchasing a DJI Phantom2 Vision. I have a pile of current and legacy traditional heli stuff and have no desire to change to a Quadcopter platform yet. I believe the Pixhawk is something special and I hope I can contribute some of my learnings to the forum.

Installing a Pickhawk on a traditional Heli and I have a few questions about a high voltage setup and how to power the servos without burning something up.
• Can the Pixhawk run high voltage servos from a 2S LiPo flight pack
• Is the maximum voltage for the supplied inline power module 18V or 4s lipo
• Can the Pixhawk be powered by the Futaba S-bus or used as a backup voltage sourse
• Can the Pixhawk control a flybarred model with H1 mixing (separate servos for pitch, roll, and collective)?

I have a Trex500 FBL I was going to use as test mule, but it is challenging to fit everything in it.

Looking at the hardware, my first choice is an older Miniature Aircraft Xcell SE99 I have converted to 12S using a Jeti Mezon 130 A controller and a Actro 32-3 motor. They are very smooth well-built machine but it is large for test mule. I can mount the Pixhawk under the main shaft and there is lots of room for everything else. This machine has good lift capacity and flight time when the head speed is lowered. Servos are low voltage and the Jeti has a 10A BEC that can be configured from 5V to 8V.

Any advice will be greatly appericated.

Ok,

Great job on the PixHawk and whomever has contributed to it’s sucess.

I purchased a 3DR IrIs to lerarn this controller and it is awesome.

This controller much further along than I anticipated. I am flying this thing 5 time a day, got the missions figured out and playing with control PID’s. I felt this would be the best way to learn, there is a lot to digest. what an awesome toy.

After some reading on the for the traditional heli
I ordered an Attopilot 90 amp current and sensor board to replace the 4S maximum power module. now I can configure the system for 10 or 12S in AMP planner 2 to read the correct voltatge in MP.

I configured the Jeti Mezon speed control for 5.3 volts and plug into a PWM input and plug in the second BEC line to the R6208SB reciever and plug the reciever S-bus into RC port.

I feel much better about the traditional heli project after using the PixHawk in the IrIs (First quad). This is were I am at so far, waiting for parts.

I am getting close with the electronics install on my heli project.

I ran into a problem, I could not get the pix hawk to communicate with the APM planner 2.0 or Mission planner on Mac or PC. I could install the firmware succesfully but I had in telemetry or artificial horizon movement. I occasionally received an error if other device using ID 255. And none on her required setup calibrations tabs were listed on the left pull down menu.

I started to unplug everything one by one an when I unplugged the magntomiter, t was able to proceed with the calibrations and all went well.

Is there anybody that has a starting point parameters list? I noticed in the extended parameters I can load default list, but there is nothing for traditional helis. It would be helpful to have a starting point for a fly -bared heli.

here is a picture, getting close.

Replaced the GPS/compass. Telemetry communication is fine and everything proceded just like the instructions says.

That was it, problem solved.

The GPS/Mag unit was bad?

• Can the Pixhawk run high voltage servos from a 2S LiPo flight pack

Yes. You can do that. I believe the max voltage is 10V on the power rail of the Pixhawk. However, if you put more than 5.5V on the rail, you lose the ability for the servo rail to serve as an automatic backup to the primary power supply of the Pixhawk, which is the power port.

• Is the maximum voltage for the supplied inline power module 18V or 4s lipo

That is correct.

• Can the Pixhawk be powered by the Futaba S-bus or used as a backup voltage sourse

I don’t really understand what you’re asking.

• Can the Pixhawk control a flybarred model with H1 mixing (separate servos for pitch, roll, and collective)?

Yes, there is an H1 mode. It’s not used or tested much, so be careful, set it up on the bench, let me know how it goes.

Hi Rob,

My S-bus question: Can the PixHawk pull power over the S-bus like a futaba reciever or gyro system? On my Helis that use a futaba system, most of my ESC BEC’s have two power supply leads to drive the reciever for supplies 10A and above. So I usually run one power lead to the reciever, and one to the FBL controller. That way, I am not pulling 9 amps over one line, the S-bus can share the load.

Right now, I have one power lead plugged into the Pixhawk and the other not connected. I want to plug the other into the reciver, So, I was wondering if the PixHawk can be powered over the S-bus?

On the Min-air machine I am working on, I am using low voltage servos Jr 8311’s and the Heli pulls 4 amps flying, so it is not much of a concern.

thats all.

BV

I recommend installing both sets of power wires from the BEC into the Pixhawk, assuming they both have exactly the same source in the BEC. The SBUS Rx should then draw power from the Pixhawk power rail. This is a better circuit construction than the one you propose, which basically makes a loop.

Some BEC’s have two voltage regulators, sometimes running on two different voltages. Some have only one regulator, and one voltage, but put the power through two sets of wires for redundancy and/or amperage capacity. Typically the connectors they use are only rated at 3 amps, so even using 2 of them to handle 10 amps is a bit sketchy, but everybody does it anyway.