Fatshark 600TVL Camera Holder for Diatone FPV250 V2

A couple of years ago, I built a 250mm quadcopter using a Diatone FPV250 V2 frame. This particular frame came with some sort of FPV camera holder that doesn’t actually seem to hold anything. So for a very long time, I resorted to zip-tying down my FatShark 600TVL camera. Inevitably, the camera would shift during flight. Sometimes the camera’s orientation would be weird but fine. Sometimes it wouldn’t be so great, often making it hard to even land.

I recently decided to do something about it. Using 3DSMax, I created three different frame-supported camera holders based on a design I found from a guy named Thomas Sevaldrud, which created a 600TVL holder for the ZMR250 frame. Kudos to Thomas for designing such a nice, and well-fitting, 600 TVL camera surround. I basically took his camera surround piece and added in custom frame mounts. All pieces were 3D printed using Shapeways’ “Strong and Flexible” plastic.

Design #1

At first glance, this design seems really nice. However, the tolerances on the gaps between the prop blades and the cage posts are pretty tight. It turns out that one of the props comes into contact with the camera holder. Not great if you actually want to fly the thing. Also, I realized that the camera is quite vulnerable in the event of a crash. The last thing I want is for my FPV system to be a casualty of my bad flying.

Back to the drawing board.

Design #2

This design works much better. The camera sits fully within the cage and the holder posts aren’t in any danger of being knicked by a prop blade. However, with design #2, my worry was that the camera holder was taking up valuable real estate inside the cage. I still have some tidying-up I’d like to do with my other components. So I wondered if I could do better, keeping the camera holder mounted using the front frame posts instead.

Design #3

This sort of blends designs #1 and #2. The camera sits back fully within the cage, and is still mounted using the front frame posts. In the design, I removed material from the frame mounts in the vicinity of the prop blades. It actually works pretty well. The only downside to this design is that I may have seated the camera holder a little TOO far back in the frame. Edges of the holder supports are slightly visible in the sides of the video feed. They don’t particularly get in the way, but they’re noticeable. I’ll fix this if I ever break it and need to reprint.


The latch is important as well. It’s what secures the camera in the holder and is used with all of the designs. (Again, big props to Thomas Sevaldrud for designing this).

The latch can be fastened to the camera holder using 2x8mm screws.


As for which design I like best between #2 and #3, I’m not entirely sure yet. It’s been too cold to fly with them. So time will tell.

If you’d like to try either of these designs out for yourself, here are the links to the STL files.

Design #2
Design #3

The inner diameter of the support posts is a bit tight and may need to be “opened up” a tad depending on your 3D printer settings. This was certainly the case with Shapeways prints. It’s not a big deal though. A 7/32″ drill bit used slowly will clean this up just fine.


Light Theremin

It was so hot and humid. It was also extremely crowded. There was barely enough room to turn around. And as usual, the idiots to the front and sides of me were either too high, too drunk, or too stupid to realize there wasn’t enough room to dance without stepping on or spilling beer all over the people next to them. I waited. And with my mind’s eye, I watched each bead of sweat travel from the nape of my neck and down my back. Did I mention it was hot?

It was August 1, 2003. Hundreds of us had packed into Bogart’s, a tiny little club in Cincinnati, OH, to see The Flaming Lips perform. We had endured hours of opening acts. When the Lips finally took the stage, the crowd tapped into its energy reserves. And it was amazing! What I had expected to be a plain ole rock show transformed into a carnival of blissful insanity complete with dancing animals, fake blood, giant balls, and an endless supply of confetti.

At some point during the show (I REALLY wish I could remember which song), Wayne Coyne began playing a theremin. Until that point, I had only ever seen theremins used for spooky, outer-spacey effects. A mood piece. I had never seen or heard one used to play an actual song, especially with a band. (Correction: Apparently that little whistle sound in the Beach Boys’ hit “Good Vibrations” is a theremin. I had no idea.) As Coyne’s arms and hands waved around in the air, producing sounds that crossed the line between melodic and psychotic, I was captivated.

I promised myself I’d try to play one someday. Unfortunately, this project is the closest I’ve gotten. 🙂

What The Heck Is A Theremin?

Source: https://www.pinterest.com/darinblass/vintage/

A traditional theremin looks like a box with one antenna popping out of the top and one out of the side. The thereminist (yes, that’s really what they’re called) moves their hands back and forth, away and towards the antennas. The proximity to one antenna controls the pitch of the sound that’s produced. The proximity to the other antenna controls the volume. The whole setup works by varying capacitance that controls a variable-pitch oscillator, which is really the source of all those crazy sounds.

Building a Cheap “Light Theremin”

A number of “light theremin” projects have appeared in my RSS feed over the past few years. And I had always intended to build one, but only recently did I actually get around to it. What follows is my take on the basic “light theremin”, as inspired by a version from Make Magazine.

Keep in mind that a “light theremin” is not a real theremin. Instead of varying capacitance, it varies the resistance of a photoresistor. And instead of an oscillator that produces pleasant sinusoidal sounds, it uses a 555 timer to generate square waves (PWM).

Below is the parts list and schematic if you’re interested. This project can be assembled in less than 30 minutes, if you’ve got the parts. And if you don’t have the parts, they can all be found on EBay for cheap.

Parts List

  • 1 555 Timer
  • 2 Photoresistors (Buy an assortment and try different ones)
  • 1 10 KOhm Resistor
  • 1 1 MOhm Resistor
  • 2 0.22uF Capacitors
  • 1 100uF Capacitor
  • 1 Speaker (Mine is a 30mm .5 Watt 8 Ohm speaker I found on EBay)
  • Optional: Assorted photodiodes
  • Optional: Potentiometer


The schematic calls for 6V DC. You can run it off of less. But as the voltage decreases, so does the volume.

Also, there are two photoresistors shown in the schematic. I had problems finding a photoresistor with a low enough resistance to use as an effective volume control. In the video below, I just used a potentiometer I had on hand. A photodiode might actually work better. At the time of this writing, I didn’t have any so I couldn’t try it.


If you have aspirations of building a performance instrument, you should probably look elsewhere. Light conditions vary from place to place. The response of this circuit can be unpredictable, even in the same room at different times of the day. Also, the audio produced is basically a square wave, which is the most obnoxious of all the basic oscillator types.

But if you’re looking for a fun project to do in an afternoon, this one is a lot of fun. Especially if you enjoy annoying everyone in your immediate vicinity. 🙂


Review: C4Labs’ Pi Squared Enclosure

I recently decided to do another Raspberry Pi media center build using OSMC. My previous build using Raspbmc was a bit of an eyesore. The original enclosure I used was one of the traditional “pack ‘o cigarettes” style of cases that are so often more functional than stylish. Cables slither from all sides of it like tentacles. The IR receiver sits next to it, forever determined to be in any orientation except for right-side-up. There’s nothing pretty about that part of our TV stand. Nothing pretty at all.

For this build, I really wanted something nice to look at. Something a bit more polished. Perhaps something that looks more like a craftsman made it and less like something a computer nerd threw together. And that’s when I came across the Pi Squared enclosure from C4Labs.

The enclosure is made of a beautifully stained wood. The top of the enclosure is customizable at the time of order, with different options for the acrylic and the wood frame that sits on top of it. There are three options for the acrylic – clear, mist (white translucent), and black (completely opaque). The wood top also has three options – Mackintosh Rose, solid (which is more of a mini-drone frame shape), and frame (think picture frame). There are even two options for case size – standard and tall.

The enclosure only has one side configured for ports – where the USB and Ethernet connect. HDMI and power are attached at build time, with the cables routed out the back beside the Ethernet port. It comes with an HDMI elbow connector for this purpose and a zip-tie to keep the power cable seated in one spot.

It fits Raspberry Pi models 3, 2, and B+ and comes with three heat sinks that are intended to be applied to the CPU, network, and RAM chips.


  • It’s very nice to look at.
  • Easy to assemble.
  • Once it’s together, it’s very solid.
  • The tall enclosure provides room for Pi HATs.
  • Provides a solution for cable management.
  • It has rubber feet to prevent scratching furniture.


  • The HDMI and power cables can’t be easily disconnected without taking the whole thing apart. This makes it hard to travel with. It also poses a challenge if you need to share an HDMI cable with another device.
  • If you intend to use the mini-jack for audio or the camera connector, you’ll need to get creative. Creative may mean a drill or a saw.
  • I’m skeptical of the heat sinks. They attach to the chips using 3M adhesive strips. Will this hold up to heat? Maybe. But I expect the one attached to the RAM chip will fall off one day. No one says you need to use them though.

All in all, it’s a pretty sweet enclosure. Perfect for a media center build. And at $15.99 (at least of this writing), it’s also a good deal. If your intention is to build something stylish that rarely needs to be moved, give this enclosure a try.

Two thumbs up.