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Beaglebone Blue based flying wing, do I have what's needed?

Hello all,

Going to have a Beagle bone blue tomorrow, I got the following parts ready to go.
X9d TX
X8r RX
Frsky flvss for voltage monitoring the system battery with the TX instead of ground station for now.
2s battery for flight controller (what are people seeing for run times with ~ 2 9g servos and the FC it self and GPS only?)
using the wifi for telemetry during testing.
got a ublox 7 gps from an older apm2.x project.
spare 4 and 6 pin jst-sh connectors to wire stuff up as needed.

This will go on a flying wing that is currently flying fine with direct control of 2 elevron servos and 1 esc with bec from the RX with a 3 or 4s main power system.

I have a laptop for the ground station software.

I am not sending Ardupilot telemetry with Frsky, only the Frsky mlvss system battery levels yet, that is the next step after basic tuning.

Am I missing anything needed to get my self in the air and doing basic testing and tuning and basic waypoint following?


Ok, updating the question.

I got a 2s setup that can just keep level at half throttle and can fly fine at 3/4 - full.

with a beagle bone blue flying in a 2s setup. does the following make sense and is expected to work power wise?

battery balance plug goes to Beaglebone Blue
battery main connector goes to esc.

lastly do I need a bec? will the 2s balance connect to FC power the servo rail? or will I need the bec to send that power? or does it support both at the same time for redundancy?

And also is the built in voltage detection from the balance port not connected? just tried it quickly and didnt see anything registering.

Yes this is ok:
battery balance plug goes to Beaglebone Blue
battery main connector goes to esc.

Concerning the battery-current sensor, it is not yet implemented on ArduPilot for the Blue.
The hardware works, I just tested with the test example comming with the robotic cape: rc_test_adc

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To clarify the current measurement, I did not mean the one that you showed me in the other post for accepting values from the ADC, but the one the beagle bone already uses for the balance plug input to drive the 4 led display, for voltage only. but it would only work for a 2s battery. or are these 2 the same thing as far as ardupilot is concerned?

The ADC has 6 inputs voltage reading : 4 analog, 1 for the Battery , 1 for the barrel plug.
So if you want to use a current sensor, it will output a proportional voltage that you read from the ADC.
The BB Blue ADC is not yet implemented on ArduPilot

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To clarify, the PWM servo output rail will be provide enough volts n amps for 4-6 servos from the a 2S Battery connected to the Beagle Blue Balance port?

Or will I want to run a BEC so I do not brown out the FC? or will running the balance port and a BEC to the PWM cause power issues?


@Z9G6 just looked at the specs for the Servo Rail regulator:
The AOZ1284 is a high voltage, high efficiency,simple to use, 4A buck regulator optimized for avariety of applications. The AOZ1284 works from a3.0V to 36V input voltage range, and provides up to4A of continuous output current

4A is 4x the average current of others Flight Controllers… You could almost jump start your car with it !! :wink:

90% answered, forgive my denseness.

But does that mean that the power is drawn from the balance plug on the FC and that 4amp and 3-36v of power can go from the balance plug to the servo rail or that the servo rail is isolated and can take 4 amps and 3-36 volts when using a BEC, or both maybe with a one way isolation?

I can be amazingly dense sometimes :slight_smile:

Thanks for being patient with me!

Yes… and you are using multiple threads to make it easier :slight_smile:

The text was the general description of the regulator, on the Blue its fixed @ 6Volts.
Do not use a BEC if you are using the Blue power on the rail.
If you dont have a multiple power source switching circuit -and that is the case here- BEC are fighting each others and overheat and ultimately blow out…

And its never ending :stuck_out_tongue: , so I have only the battery plug into the Blue with the Balance port and I do not get any power to the servo rail? I know I am missing something obvious.

You are missing the SERVO_ENABLE signal

Well… this is more tricky… until we get it into the ArduPilot code, you will have to enable manually within the the startup script

Its a matter of echoing the enable bit at the right gpio port mapping within user space…I need to dig on that

Meanwhile just feed the servorail with a BEC

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Looking at schematic, we see it driven by lcd_data_10 wich is GPIO80

Here is a simple guide showing how to:

Please note that on the robotic cape image, GPIO80 is already exported and available
you need to bee root to work here : sudo su
so you can try:
root@beaglebone:/sys/class/gpio/gpio80# echo out > direction
root@beaglebone:/sys/class/gpio/gpio80# echo 1 > value
and the 6 volts appears on the rail :slight_smile:

so, depending how you plan to start ardupilot, the simplest is to use /etc/rc.local file
make the rail powered before launching the ardupilot using:
echo 1 > /sys/class/gpio/gpio80/value

have fun

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is this because of the newer debian and rt kernel I decide to run?

I will try those commands shortly, Thanks, you have been very helpful!

so I was planning (once I found the info on how to do it) to make the pus and mod buttons start and final arm ardupilot. I could switch the start one to run a script that starts the GPIO first then the ardupilot.

No, its not the new kernel its because you are the first to try flying a plane on the Blue :wink:

For the rest , I suggest you come here:
This is where BeagleBoners are hiding

and the power light turned on for my receiver! thanks again!

Servers by jDrones