Saturday, May 1, 2021

In Flight - Quad Lifts Off

There are times that you find yourself in boring, remote meetings.  And there are times that you remember the old quad copter you built ages ago.  And then there are times you find yourself addressing a few issues.  After I put it together and configured it, I had a few issues.  I could never get it to lift off, even with launch control.  Also, after a few attempts, I didn't have any camera for FPV flying.  I had the OSD, but I did not have any video feed other than a black OSD screen.

First, I set to figuring out the launch.  Usually, it's because either a propeller is spinning the wrong direction, or the front, top, or right side is not set right.  It took a few iterations to figure it out (in the Betaflight Configurator, it would roll the opposite direction, but the pitch was good).  With that set, and without a video feed, I was able to get it airborne and do some simple flying.

Next up was to tackle the camera feed.  Knowing I had OSD on a black screen, that eliminated the transmitter, and the flight controller that added the OSD.

I bypassed the OSD plugs on the flight controller just to make sure it wasn't the flight controller and had just a black screen, so I knew this was the camera.

I plugged in another brand new camera, just to make sure it was good - no dice.

That told me it was a potential problem with wiring, but I had to make sure.  I contacted RunCam, and they sent me a quick "picture" of how to wire so I could build a test rig.  The camera I had came with a few cables, so I took the spare, and cut into it.  I used a plug for the 4S battery that powers the whole thing.  Here's how, using only the three essential wires (the negative power connects to both the camera and the cable) :
  • The battery negative (RunCam called this "ground" - it's really not) connects to the camera ground and the outside of the RCA/Composite cable
  • The battery positive connects to the 5V input on the camera (it accepts 5V to 36V, so the 14V of the battery was sufficient)
  • The "video" cable from the camera connects to the center of the RCA/composite male plug
A picture is worth a thousand words, right?

After a quick build of the cable, I had my rig, and hooked the camera up to the video output.  I used my flight battery to power it up, turned on the monitor.... and I had video.  I checked both the old camera, and the new (the old was simply a little blurry, so I could adjust it while I was there), both being successful.

That told me my problem was really in either the flight device not receiving video, or the camera was not getting enough power.  I took it apart, and I found the 5V line feeding the camera was coming from.....

.... the 5V pin on the video transmitter?  Huh?  What was I even thinking?

I measured the voltage and found 4.7V.  The flight controller had a 10V output, so I rewired the video camera to the 10V, and sure enough, I had video and OSD together.

Headed out to test it, and this thing is extremely sensitive and responsive.  This is wicked fast and maneuverable.  I need to get to open spaces to play with this.

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