Fix for “No MAV Data” on MinimOSD-Extra with 3DR Pixhawk

I’ve been battling the “No MAV Data” notice appearing on the MinimOSD video output after powering up my Pixhawk flight controlle, this has happened out of the box and persists after flashing the 4.0.1 MinimOSD-Extra firmware. Here’s the fix.


  • I have a MinimOSD with KV Team Mod.
  • I have the MinimOSD connected to the Telem2 connector (known as SR2), a 3DR 400MHz radio is connected to Telem1 (known as SR1)
  • The MinimOSD board is powering the 5v FPV camera by bridging the UART and video pins.

The fix

  1. Open Mission Planner
  2. Connect to Pixhawk
  3. Open the Config/Tuning tab and expand the Full Parameter Tree
  4. From the Paramater tree expand SR2
  5. Set the following values if blank (or set to 0/zero):

    SR2_EXT_STAT, 2
    SR2_EXTRA1, 10
    SR2_EXTRA2, 10
    SR2_EXTRA3, 2
    SR2_PARAMS, 10
    SR2_RAW_CTRL, 1
    SR2_RAW_SENS, 2
    SR2_RC_CHAN, 2

  6. Click Write Params

That’s it!

Check your MinimOSD video output as this is an immediate change and does not require re-powering your Pixhawk flight controller.

Adding Retractable Landing Legs to Predator 650

I bit the bullet and purchased the 600-class Quick Release Universal Retractable Gear Set to upgrade from the Crab Leg Landing Gear Set on my Predator 650 build.

Upgrading to a servo-driven landing leg set means the legs can be toggled to raise/lower from a spare channel on the receiver, I envision using this for aerial photography where footage is currently obstructed by the crab legs.

I chose the 600-class retractable gear set as I wanted only a single channel sacrificed on the receiver and didn’t want to run two 450-class sets – which is designed for smaller frames – in parallel.

To mount the retractable gear set to the frame I purchased 4 x Shock absorbing CNC aluminum tube clamp (10mm) which will fit the 10mm rails on the underbelly of the Predator 650 frame. A perk of this particular landing gear set is below the servo bar is ideal space to mount a camera gimbal, this be be done without modification.

I’ll update this post when the item arrives 🙂

[5 days later…]

Retractable landing legs arrived and they’re big! I’m thinking the 450-class set would have been fine, but I have not installed them yet so am still confident I made the right choice. Also the 4 additional tube clamps were unnecessary as the frame includes its own set.

The bulkhead that houses the servo’s has holes punched into it to suit a larger frame, they’re too far apart to be usable with the Predator 650 so I’ve drilled my own holes in line with the underbelly rails of the 650-frame.

Additionally since there’s so much space on either side of the bulkhead I’ll move my battery from the underbelly of the frame –  was strapped behind the 4-in-1 ESC and FPV camera – up onto the bar and install a 2nd 4500mAh 4S battery to balance the weight out.

Connecting external LED’s to Arducopter

Before I shelled out for the dedicated Aircraft Navigation Lamp Set (install guide here) from HobbyKing I wanted to add some basic LED lighting to the motor arms of my X525 build, I still use these LED’s as one displays the Motor Arm status, the other the GPS Lock, that and the dedicated navigation lights don’t talk to Arducopter.

Update: The voltage of the LED strip has to be 5V. Too low, your strip will burn. Too high and it might not turn on (thanks Wei).

Here’s what you need and how to install it.

What you need

Connecting the LED’s to the APM board

If you went out and bought the 3 LED strip’s mentioned above you can connect the LED servo cable’s directly to the APM board’s analog input’s after a quick change of one of the leads to the JR connector.

We can connect these particular LED strip’s directly to the APM board as the LED’s draw less than the maximum permissible current of the AVR chip on the APM of 40mA per input, the LED strips we’re looking at draw 33mA per input.

Update: The current limit is 40mA per pin or 200mA total. Any higher and you risk damage to the APM (thanks Wei).

By moving the positive lead (red cable) over one spot to occupy the signal line APM can power the LED lights on/off when it chooses, left unchanged the LED strip will be connected to the +5V rail and be always on; which looks cool but is useless.

  1. Using a small sharp knife lift up the tab on the positive lead (aka red cable) of the JR connector that holds the pin in place
  2. Pull on the positive lead while the tab is lifted to remove it from the JR connector
  3. Re-insert the positive lead into the space typically used for the signal line (the next available space) of the JR connector
  4. Make sure the tab is down and the positive lead is secured by giving it a pull



We’re not looking at adding buzzer support today but here you can see where the analog input’s go on the APM 1.6 board.

If you’re using the current release of APM then you’re on AC 3.1.5 (Arducopter 3.1.5) and the following will apply, read further for the AC 3.2 changes which will apply when AC 3.2 is officially released.

AC 3.1.5 (today)

  • A4: AUX led
  • A6: GPS – will flash with no GPS lock, solid with GPS lock
  • A7 through A11: Motor LED’s (always on)

AC 3.2 (future)

  • A4 : Motor LED
  • A6 : GPS – will flash with no GPS lock, solid with GPS lock
  • A7: Arming LED
  • A8 through A11: Motor LED’s (always on)

Note: Need to confirm A8 through A11 for AC 3.2 and above as this is not currently documented on External LEDs from Arducopter Wiki.

Connect your LiPo battery and power up your APM board, lights on, enjoy night flying! When you’re ready consider upgrading to the Aircraft Navigation Lamp Set (install guide here) mentioned earlier as you can then add real-world lighting sequences to your build.

Connecting aircraft navigation lamp set to Arducopter

I got around to connecting the Hobbyking Aircraft Navigation Lamp Set to my APM 1.6 clone board today, here’s a run through of the wiring guide for connecting each LED to the distribution box as well as placement for an X-frame quadcopter. There’s also a guide for controlling the lighting modes with the Turnigy 9XR transmitter and a dummy list of available lighting modes.

What’s included

Included with the Aircraft Navigation Lamp Set is the following:

  • 5 x white LED’s with 2-pin micro moxel connectors
  • 2 x red LED’s with 2-pin micro moxel connectors
  • 1 x green LED with 2-pin micro moxel connector
  • 8 x plastic LED grips for mounting the LED to frames
  • 1 x distribution Unit with micro molex connectors for the LED’s
  • 1 x servo cable with 3-pin micro molex connector for powering and controlling the LED’s

The total draw of the LED lights and distribution unit is less than 100 mAh and is self-powered from the receiver channel it is controlled from.

Available lighting modes

You can choose from the following lighting modes:

  1. Coloured arms always on, strobes and beacon flashing, landing lights fade in/out
  2. Coloured arms, strobes and beacon flashing, landing lights fade in/out
  3. Coloured arms flash twice on each arm
  4. Coloured arms flash twice on each arm at higher frequency
  5. Coloured arms and strobes always on, beacon light is flashing, landing lights fade in/out
  6. All lights flashing at high frequency
  7. All lights flashing at slow frequency
  8. All lights on
  9. All lights off

Guide to connecting LED’s to assigned connectors

See the list below for details on connecting LED to assigned connectors.
  1. Strobe light on front-right arm
  2. Landing light on rear-right arm
  3. Beacon light on front of main frame
  4. Strobe light on front-left arm
  5. Red light on front-left arm
  6. Landing light on rear-left arm
  7. Beacon light on rear of main frame
  8. Green light on front-right arm

Controlling the lighting modes with the Turnigy 9XR transmitter

Ensure you’ve connected the supplied servo cable from the AUX connector on the distribution unit to an available channel on your receiver (I chose channel 8) before proceeding.

  1. Power on the Turnigy 9XR
  2. Hold the Menu button for a second to open the Menu screen
  3. Switch to the Mixer screen on tab 5/11 by pressing the right arrow button
  4. Using the down button only highlight ‘100%’ on the available channel on your receiver that you connected the distribution unit to (I chose channel 8 so went down to CH8)
  5. Hold down the Menu button to display the Edit Mix screen for this channel
  6. Ensure the Source is set to FULL
  7. Press the down button only to highlight the Switch option
  8. Using the left and right buttons only change the value to TRN
  9. Press the Exit button only to return to the previous screen
  10. Press the Exit button repeatedly until you are on the initial status screen

You’re done! Connect the LiPo battery to your quadcopter and flick the TRN switch on the far-right of the Turnigy 9XR controller to switch through the lighting modes.

Hobbyking Predator 650 kit parts

Notice: This parts list is ongoing, if you know the dimensions of a missing part or think this can be better drop a comment below 🙂


  • 44 x M2 x 6mm
  • 46 x M3 x 6mm (button heads)
  • 40 x M3 x 6mm (flat heads)
  • 12 x M3 x 10mm


  • 2 x […]
  • 2 x […]
  • # x M2.5 x 22mm


  • 1 x 23*25*248mm carbon tube
  • 6 x  25mm aluminium blocks
  • 6 x M2.5 x 40mm
  • 6 x M2.5 nuts

Hook and Rod

  • 2 x 10mm tubes for undercarriage (rail mounting system for battery, gimbal, etc.)
  • 4 x […]



Build log


Build Tips


  • Build the motor arms first and mount them to the rear section prior to attaching the rear landing legs to the frame.
  • Do not lose a single screw. A single screw. There are no spares available from the supplier at this time.


Hobbyking Predator 650 equipment list


Control Board


  • Turnigy Multistar 2814-800Kv 123 (HobbyKing didn’t stock the 2814-800Kv so I pulled the trigger on the smaller 2214-800Kv, not ideal as the motor mounts don’t all line up but close enough, in hindsight should have waited for the 2814-800Kv)
  • NTM 28 Carbon Fibre Motor Mount (as above, used the cross mount from this kit to mount the Turnigy motors with holes 16mm & 19mm to the Predator 650 motors mounts with holes 19mm & 25mm, no motor mount screws are provided so used screws scavenged from previous builds to mount the the cross mount to the motor mounts, if you get the 2814-800Kv motors mentioned above you mount directly onto the motor mounts)

Speed Controllers






X525 Quadcopter equipment list

Here’s my shopping list from HobbyKing, eBay sellers/other RC suppliers for my new X525 build.


Control Board


  • […]

Speed Controllers

  • […]