New CTEC Keycoder

I think I’m almost done with my new keycoder, it’s gone thru several iterations and I’ve ironed out most of the bugs.

I’d posted earlier this week that I’d started with a box I made out of aluminum angle, and added a bunch of momentary toggle switches, I then took the guts out of two RF remotes and wired them up inside. Sounds easy but it didn’t feel like it at the time.

The switches are mini (on)-off-(on) momentary, I really wanted to try and get sub-mini’s that just did (on)-off, but I couldn’t find any at a price I was willing to pay. I think the switches I ended up with worked out to be around a $1 each after shipping.

Space is very tight and I really didn’t want to make the box any bigger than absolutely necessary, so I ended up trimming the RF boards down and consolidating the antennas as well as removing the two batteries.

The switches center solder tabs are common and wired together

This is the spaghetti I’d created once I was “done” wiring the switches in

With being generous with the wire I’d forgotten it all had to fit in the box somehow! So I ended up shortening everything down. I also wrapped the backs of the switches and any critical parts of the boards in electrical tape.

I’d tried really hard to fit rechargeable batteries inside too, but ended up with a better solution I think. I ran a cable out and up into the battery compartment of the Futaba to share it’s battery. The cable has a Y split in it for easy removal. The RF remotes come with a 12V battery, but I’ve tested and found that they work very happily on the 10VDC coming from the Futaba. When I double checked my older remotes their batteries had dropped to 6V and were still working fine.

So, that’s my new CTEC keycoder almost done.

Lessons:

  • Having the antenna internally limits range so I’ll be moving it outside.
  • Total cost was roughly $94 (incl. two RF setups $60, aluminum $10, switches $24), and about 2 or 3 days of work. On the other hand the Vantec Hitchiker product is around $450 – and only works with their special Futaba 75Mhz FM 9CAP, but does have some great features that I will need a cheap micro-controller to replicate.
  • My keycoder weights in at 10oz, adding to the already heavy Futaba setup at almost 2.5lb. So I may look into making a plastic box – but the weight of the switches definitely adds up.

One last trick I learned is that you can have multiple remotes control a single RF receiver. Yep, you heard that right. I’ve been controlling multiple RF receivers with one remote for a while, but had no idea it would work the other way around – each remote doesn’t not need to have the same code even. I accidentally found this out while trying to mate the new keycoders remotes to my droid and found that my older remotes still worked.

Related:

Posted by Chris on August 6th, 2008 in Electronics | 3 Comments

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Mystery Box

Anyone want to hazard a guess what I’m trying to make here?

This photo should give it away

More photos in a few days

Posted by Chris on August 2nd, 2008 in Electronics | 5 Comments

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Mounting RF Remotes to the Futaba

I had to find a better way to mount the RF remotes to my new Futaba transmitter. I’d originally had them mounted to the sides of Vex transmitter, but really didn’t want to go this route this time around.

I’m still toying with the idea of taking the electronics from the two RF remotes and installing it all in a custom box that would look similar to the Vantec HitchHiker /keycoder, but it’s been almost a year since I blogged something similar, and I’ve yet to do it 🙂

After some experimentation, I went with a very simple acrylic bracket to fix the main RF remote on the front of the Futaba, making it very easy to control with either hand. It does cover the screen, but to be honest it’s rarely used and the bracket is easily removed or lifted.

The bracket is only secured in one spot, the bottom of the Futaba with Velcro for easy removal.

I mounted the second RF remote sideways on the battery compartment on the back of the Futaba. Right now it only has functions that aren’t used often, so I don’t think it’ll be to inconvenient having it there.

The only real catch with this setup is the antennas, occasionally I’ve found it necessary to extend them if I get to far away from Artoo.

Posted by Chris on July 6th, 2008 in Electronics, RC | No Comments

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Mounting Dome Electronics

I was getting tired of my disorganized electronics in the dome, so I made this little holder that mounts everything cleanly and is easily removed.

It’s just a piece of acrylic bent into a U-shape with an extra L-shaped shelf glued in the middle.

The various electronic boards are velcro’d into place for easy removal and the whole thing attaches to one of the dome ring supports.

Top: Syren10 Speed Controller (Dome Periscope), 12V/24V DC/DC Power Converter
Middle: Power Distribution Board
Bottom: 12 Channel RF Receiver

I secure the wires that run up to the dome to make sure I don’t accidentally pull everything off when the dome is removed

Please ignore the 16 gauge wire as well, I was running short of something lighter but didn’t want to make a special trip to the store.

See also:

Posted by Chris on April 28th, 2008 in Dome, Electronics | 8 Comments

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What the Beep!

The sound the little RF Receiver made every time I pressed the remote was really bugging me, so before going to bed I decide to remove the little ‘siren’.

I tried searching the internet and even found the new support forum for the product, but nobody seemed to know if the bleep could be turned off programatically, so I decide to simply remove it.

The siren or buzzer is located in toward center of the board

12 Channel RF Remote - Siren

I used a de-soldering tool to suck out the solder

I soldered in some wires just in case I need to re-attach the siren later to change the RF code. Sorry it’s such a bad picture

Much better 🙂

02/10/08 Update – Here’s the board with an LED added in place of the buzzer (don’t forget to add a resistor on the positive leg. Resistor size will vary and depends on your LED. Source voltage should be 12V, so as an example given a 3.3V LED with a forward current of 20mA, you’d use a 470 ohms resistor but something bigger will work too, but the LED will be a bit dimmer.)

Posted by Chris on May 8th, 2007 in General | 3 Comments

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