Wireless display model electronics help!

[bob the builder]

Gents,


I'm hoping that someone could point me in the direction of where I might get information (or preferably some sort of kit) that would allow wireless control of approximately ten channels of a static build that I'm working on. Ideally at least a few of the channels could feature reversible input somehow (on/off/on reverse). IR or radio communication are both fine. I did a quick search but haven't found exactly what I'm looking for.

What I'd like to do is build a control box that would have all the buttons on it to control the model's features that the customer could use from across the room (or at least from a few feet away). Each feature is very low current draw.

Does anyone have any idea where I could start?

Help is greatly appreciated!


Bob

[Guest]

Re: Wireless display model electronics help!

Picaxe processor used with a Sony infra red remote would work and inexpensive. Means a bit of breadboarding though.

You could also use a second Picaxe to act as a TX if you wanted to make it look themed (a TV remote would be tricky to modify in this respect).

What sort of things need to be switched Bob? Is it simple on and off functions, or are some proportional. Any motors need to be switched, and if so, do they need to be proportional?

Andy

[bob the builder]

Re: Wireless display model electronics help!

Andy,


Each channel does not need to be proportional. I will be switching small motors and lighting channels. Each channel really just needs to be a simple relay on/off. If I can find a system where I can get three channels reversible, that would be perfect, but I can probably work with what I find.

[Guest]

Re: Wireless display model electronics help!

Okay. To get motors unning in both directions, you need to make an h-bridge-

http://en.wikipedia.org/wiki/H_bridge

You can do this using solid state transistors (also available as monolithic devices) or relays. For the latter you need two double pole double throw relays (the boards that engel supply with their piston tanks use these). Thinking laterally, if you have a couple of cheap esc's kicking about you can use those- the Picaxe will operate them just fine. What sort of voltage/current are you looking to drive?

[bob the builder]

Re: Wireless display model electronics help!

I'll be running this off of 9VDC, Andy...

[Guest]

Re: Wireless display model electronics help!

Okay, esc's will work for that and will simplify the hardware side of things but will add a little more expense. So how many channels do you need? Also state which ones you need for switching lighting (how many lights do you want to switch BTW, and are they LED's) and for bi-directional motor control.

[JWLaRue]

Re: Wireless display model electronics help!

...not sure if cost is a real issue, but why not just use a 2.4GHz system?

-Jeff

[bob the builder]

Re: Wireless display model electronics help!

Cost isn't a huge issue. I'd give up dollars in exchange fir ease of use, clean installation and reliability. I was actually thinking of using an r/c system, but I need a nice control box. This is for a high end display model, not an r/c boat.

An expanded module like that in my typhoon's F14 would be perfect as I could get a ton of channels and have a few proportional ones as well... Hmmmmm...

[Guest]

Re: Wireless display model electronics help!

Infrared is the simplest to implement. Using 2.4ghz set is bit overkill IMO if you just want something that switches functions on and off at close range, not to mention 10 channels (sorry missed that earlier, must pay attention) is a bit tricky to implement with standard R/C without resorting to fiddling with the standard 50kz pulse rate, or using multiplexing.

So basically you need three reversible channels and seven basic switched channels for lighting?

[JWLaRue]

Re: Wireless display model electronics help!

...perhaps a slightly modified iPhly?

-Jeff

[bob the builder]

Re: Wireless display model electronics help!

I need 6 on/off and 4 that can go on/off/and then on in reverse.

As a bit of background, this will be the system that runs the features on a Disney Nautilus model. The reversible channels will open and close the hatch, slide the breathers, raise/lower anchor, and open and close the salon iris. The rest are lighting channels, anchor, etc.

[Guest]

Re: Wireless display model electronics help!

I'd have used servos for many of those functions- easy to control using Picaxe and cheap as chips. However I guess you already have the hardware installed. Do you have limit switches installed for the motorized functions?

[bob the builder]

Re: Wireless display model electronics help!

This is a new build, Andy, so I can use almost anything. The PicAxe sounds intriguing, however I don't know anything about it...

[Guest]

Re: Wireless display model electronics help!

Ah right.

Picaxe- http://www.rev-ed.co.uk/picaxe/

Very easy to program (they use BASIC), very inexpensive (no fancy programmers needed) and lots of routines built in ideal for R/C modellers. For instance- routines for controlling servos, receiving pulses from R/C receivers, easy communication with serial devices which enable extended functionality.

A Picaxe or two can equip you with hundreds of channels on your R/C set, for less than a fiver. Or it could be a custom failsafe, flash lights in sequence or move servos in a preconfigured routine at the throw of a switch. That is just scratching the surface. The only limit is your imagination and programming skill.

Fundamentally, PPM R/C is 1960's technology, that's why you're limited to 8-channels- extended channels are achieved by fiddling with the standard, which is why you have to use proprietary (read flipping expensive) receivers for those sets which have more channels or use multiplexing like the Robbe modules.

An infrared system for your build could be built around a pair of Picaxe 20X2 processors, with a handful of extra components. Cost would be about $14-15. You would need to add to this the cost for motor control components and any power transistors required for switching the LED's. Also you would require some sort of enclosure and off course the switches to operate the various functions.

Andy

[Guest]

Re: Wireless display model electronics help!

Standard R/C servos are capable of about 180 degrees of rotation without modification. With a little light modification this can be extended to about 270 degrees, and with a lot of modification you can extend the throw to what ever you like (within reason), by removing the potentiometer from the case and using this in conjunction with a lever or gearbox.

With servos available for about $2 from Hobbyking, you can get a nice cheap feedback controlled actuator.