A Little Ditty for the New Year!

[JonnyMac]

Sometimes very small things can make a very big difference. Something John B. and I have long talked about, but didn't have time to do until now, was to make a very simple plug-and-play relay board with the relay we found and use on the AP-16+ and the EZ-3micro. It's a beauty: it runs from 5v an only takes about 75mA (per relay, that is) -- something any of our controller 5v supplies can easily handle.

So here it is, the RC-2. Two inputs, two Form-C relay outputs. Easy-peazy. Since this prototype I've turned the WRB connector around to match our other boards and I added a pull-down so that it can be used with Parallax BOE's, Arduino boards, etc. Each relay has its own LED so you know it's being told to be "on."

I also did a version called the SSR-2 that is the same form factor (2.1" x 2.2") but uses two solid-state relays (for those times you don't want the mechanical clicking...).  Another "little" board we've got a working prototype of is a tone-decoder board which is really exciting: you plug in an audio source (like one side from an AP-16+) and it will switch a 12/24v transistor output or you can connected it to a controller to use as a trigger when running props that you want to sync to a DVD or other video/audio source. You can chain your audio source from one board to another which will let you do simple animatronics without using a programmable controller (use Audacity as your audio editor / output programmer).

We'll have all these things ready for Transworld, along with some bigger projects that we will keep under wraps for now.

Happy New Year from your friends at EFX-TEK.

[bsnut]

Happy New Year to you and JB and the rest of the EFX-TEK forum members.

Another "little" board we've got a working prototype of is a tone-decoder board which is really exciting

Are you going show off this cool little board with a picture of it?

[JackMan]

Jon,
   Does the "Tone Decoder" board use DTMF tones or does it just activate on any audio input? Happy new year to you and JB, looking forward to Transworld.  ;D

[JonnyMac]

The tone decoder is for single frequencies; it's our take on the standard LM567 circuit. We've made it prop-user friendly with both RCA (mono) and 3.5mm (stereo, with channel select jumper) inputs. As soon as JB sends me one I'll post a pic. We have a small mod we're going to make before production, but we know the circuit works. It has active-high and active-low TTL outputs (which can also power the board if it's just being used as a trigger), and a transistor output for direct control of valves, relays, etc. (using this output requires adding power to the board).

[JackMan]

So, does it activate on audio input and stay active? How does it de-activate?

The tone decoder is for single frequencies

Is this a specific tone, or any audio?

[livinlowe]

if this board works like some of setups ive researched online, it responds to one frequency. like a 44khz tone (just as an example). Im pretty sure that is easy to insert with audacity

[JonnyMac]

So, does it activate on audio input and stay active? How does it de-activate?

When correct frequency is detected the output is active; when it goes away the output shuts off. Easy-peasy.

Our board design will go from about 440Hz to 19kHz using a multi-turn pot (for fine adjustments). The range within the pot in not linear (due to RC circuitry); for example, the midpoint of the pot is about 900Hz (we will test and preset to 1kHz). All that said, most audio devices cannot reproduce the high-end frequencies very well (even the AP-16+ starts to roll-off at about 16kHz which is well above normal human hearing). The bandwidth of our decoder is pretty tight (about 40Hz) and when using multiple boards we'll probably recommend something a little more liberal (about 200Hz) so that you can easily distinguish different tones when listening to them on the track.

I've also started jotting down ideas for an Audacity tutorial specifically on "programming" for sound based control.

[JonnyMac]

Our friend Greg from Ethereal FX is visiting John in the home office this week so I asked him to snap a photo of our prototype TD-1.  John has been have a good time with it and we're excited.  I've updated the PCB to Rev B which is what we'll put into production.  The production board will be a tad wider (2.1" x 2.2" to match the RC-2 and SSR-2), has OEM power pads for those that want to solder it into a circuit, and will use a different output device. We don't like that the TIP120 stands so high above the terminal blocks. I've found a cute little n-channel MOSFET that is easy to sub in and gives us the current we want (1A @ 12v).

Note that we're expanding the size of the mounting holes to make our boards easier to mount.  John found some great nylon mounts that use a screw on the bottom, a snap-flange on the top -- now you can take out boards without worrying about dropping and losing screws!

[bsnut]

Now that's a nice board Jon thanks showing it off us.

[JonnyMac]

We're quite excited about it -- funny, as it's such a simple board. I've attached the update layout. After JB checks we'll send out for a new set of boards and if all is well roll this one into production.