Binary Candy–Rack part 2


Reader stand

After a bit of experimentation and debate with myself, I’ve decided on an almost vertical arrangement for the reader. This allows the numbers to be reached and slotted in easily even by 3 year olds, something I’m keen on achieving.

Using the mitre circular saw I’ve created the wedges and blocks, they will be held in with wood glue, its totally adequate for a job like this and avoids unsightly screws.


It stands up!

So now the glue is dry I’ve used the multimeter to determine the best level for the lowest possible position for the reader. I made the reader slightly wide to stop ambient light getting down into where it reads, but this means I do need to position it as low as I can to give a good position for slotting the numbers in and also seeing what they are.

It looks great and I’ve very happy with the angle I chose to go for!

Binary Candy–Binary Tiles

Making the Binary Tiles



Creating the tiles! Using circular saw and lots of careful measuring I have some rectangular tiles.
They are designed to show what the number is (one or zero) above the reader a little, be shaped to ensure they are inserted in the correct way around. They are also of a size that they are fairly big for other visitors standing behind the person participating in the task to be able to enjoy the fun with them (keep it as inclusive as possible). It is always important to thing about both the people who are interacting with your maker project and the other nine or so standing watching!
I’ve made a few extra tiles in case of accidents or losses.
In the photo above you can also make out the reflective sensors peeking through the holes in the detector board.

Now for primer on the MDF tiles…


White tiles get spray painted


Number digits
I used paper template cut out and spray paint, inverse to the background colour to make ones and zeros. I was up at midnight spray painting on neighbourhood pavement away from houses, must have had neighbours talking!
I struggled with this one, I was trying to make the numbers almost look like graffiti in style, just causally sprayed on. Problem was the engineer bit of me wanted to pefectly centre and mask off each one and touch up any imperfections and do a couple of coats each to get a pristine number.

This is supposed to be inside-out maker style project I kept telling myself. I managed to just leave them looking “casual”.

I am struggling with the style of this project!

Using UPVA glue as varnish - trick I got from my Son. Mind you, now  the house smells like a infants school!
The glue you see above will dry to be transparent and will hopefully stop the paint numbers from wearing or getting scratches or chips.


The finished numbers ready for action 9 of each should be plenty!


Binary Candy–Planning and rack build

Inside-out ethos of this project



Not quite literally inside-out, but this project is where I’m having to really wrestle with myself. At every step I want to hide the wires, the sensors, paint everything to a high quality smooth finish. However the words of a fellow maker ring in my ears, from the first Makerfaire we showed at. He said how its the only place where you get a bigger crowd around you by stopping your invention and taking the lid off than when it is running. So in this spirit I’m trying to make everything on this project look open so you see the wires on the front the painting is not finished, electronics is showing. Already I’m struggling with my instincts to make everything small, hidden and highly finished, but here goes…

Building the main binary input device “rack”

After buying some MDF and lots of cutting with the mitre and circular saws, construction really begins now for this Binary Candy project.

The main back board is cut, I’ve routed out the recesses that the MDF tiles (with the ones and zeros) will slot into.

I have found the routing left the MDF less than smooth, so I’m going to put a few layers of UPVA glue on and sand to give a smooth slot for the tiles to slide into.

I’ve forced myself several times not to paint the MDF on the detector board already to follow my home made, thrown together look I’m wanting this year.

I’ve cut some tiny Vero board squares to mount the reflective sensors. The sensors have a infrared LED that shines onto the surface in front of them and a detector that measures the reflected light. My plan is to mount these in a position where they will see the back ground colour of the tiles. Ones and zeros will have inverse colours to make them discernible from one another.
I have gone for eight bits as it gives the visitor the a good number of tiles to wrestle with, yet hopefully not overwhelming the younger visitors.

The sensors have been friction fitted through holes exactly in the middle of each digit position. I’ve fought with myself to not hide the wires in the reverse of the reader stand, instead everything is up front and on show. -ewww I’m struggling with this way of doing things! :)

All in all I’m amazed how quickly its coming together in a I already have a major part of the hardware done.
The sensor board goes to a .1mm pitch IDT connector for quick assembly. I’ve leant from earlier shows that it is best to have a quick fool proof robust way of building and dissembling the project.

Syma X8 X8C X8HC FPV with RunCam 2 cable

When flying blind with a RunCam 2 slung under my Syma, I wanted to see what I was pointing at when flying rather than guessing. The solution was to send the video back down via a FPV transmitter.

Required parts:

  • 3.5mm jack plug or chopped up jack to jack cable
  • Solder Micro USB plug (ebay etc)
  • Some small lengths of interconnecting wire
  • VTX 20mW that can work from 5V
  • FPV Goggles to view the transmitted signal

Syma X8 camera socket

The Syma has a 3.5mm jack socket used for the camera module that came with it and in my previous post I explain what the connector pins are.

SYMA X8C X8HC 3.5mm pin out camera control signal

The tip and screen of the connector can provide a five volt supply for a FPV module. I went for the

Eachine VTX03 Super Mini 5.8G 72CH 0/25mW/50mw/200mW Switchable FPV Transmitter as it can run from 5 Volts, is small and easy to work with.  I recommend a 25mW transmitter, the Syma does not cope with any higher demand than that on its power rail. The VTX03 is switchable between three power ratings, make certain you read the instructions and set it to 25mW.


Make a Cable 3.5mm & Micro USB

Next you must make a cable to connect the RunCam and drone together. The RunCam outputs video when it is on via its Micro USB connector. The FPV unit needs a 3.5mm Jack to get power from the drone.

So go to the Dollar or Pound shop and get a cheap 3.5mm to 3.5mm cable, used for linking many audio devices together so is easy to find, or chop one off an old pair of headphones.

Wire the tip of the connector to the power Red wire of the VTX. Wire the shield (not the ring), to the black wire of the VTX power. You will need to chop off the tiny white connector that comes with the VTX to do this, the power only has two wires, red and black going to the white connector.

To test, plug in the 3.5mm jack plug, making certain it is fully into the drone socket, turn on the drone and the LED should illuminate on the VTX display showing it is getting power.

Next unplug it again. Now you will need to use a solder micro USB connector. I had no luck with cutting up Micro USB cables for this, as I don’t think they use the same pins as the RunCam. Wire the yellow wire from the VTX to the Video pin indicated in the photo below. Then wire the GND pin of the micro USB connector to the Video GND pin of the VTX (black). The Video cables are the three wires going to the tiny white connector on the VTX. You will have one wire unused on the VTX of the three.

Hot glue the wires where they attach to the PCB to prevent them bending and thus falling off. Also glue in the cable as required to the rear of the connectors to give it some strain relief. You should also heat shrink the antenna to the PCB to prevent it popping off in flight or on heavy landing.

 Video Pin Micro USB Runcam 2

GND pin RunCam 2 Micro USB

Plug the Usb into the RunCam, the 3.5mm jack into the drone and turn on the RunCam (it will power from the RunCam battery so make certain it is charged), turn on the drone. You will then be able to see the picture in your FTV goggles! Now secure the VTX module to the jack plug with a cable tie, this is a better solution that taping it a Syma leg, as if the leg comes off during heavy landing, there is a good chance your VTX wiring harness will be snapped too.