Electronics Noob... With probably impossible requests..HELP!

[sheffladreece]

New to the forum first off let me say hi to you all, and i look forward to hearing any solutions, suggestions and or advice that you may have regarding my problems here on.

Firstly very very basic knowledge of circuitry... Although more than capable of learning new concepts quickly.

Basically, what i am attempting to achieve is to have a remote that wirelessly turns multiple DC motors on and/or off at any given time possibly upto 20, if achievable? Within a 50m radius.

I want the remote to have the ability to turn on or off a single motor, multiple motors or all motors at once if necessary.

These motors are not to be linked to one-another and are to be viewed as separate units.

I would also like the ability to add motors to the remote if i need more, for example i may start off with 1-2 motors linked into the remote but then i would like to add further motor units to turn on or off.

If possible i would also like to ensure that no one else can turn on or off the motors via another wireless remote unless there are linked together in some way (bluetooth link possibly).

Ideally, i would like for this solution to be as cheap and small as possible i.e. the remote to be under £10 and the motor units to be under £5. And size wise the remote to be no larger than a standard tv remote and the motor unit to be no larger than 2cm wide by 15cm length and 3cm depth.


Please feel free to offer any advice/ solutions/ opinions/ alternatives to the issues above and also prove/disprove any of the requests that I have asked for in the above statements.

If you do disprove any of the matters, could you possibly offer an alternative solution.

As said previously I have very basic knowledge of electronics and therefore many of these requests may not be even possible, so apologies for lack of knowledge on my part.


Thanks


Sheffladreece

 

[shumifan50]

Are they, or could the receivers be in line of sight of the transmitter?
Any wireless application runs the risk of hacking from beyond your premises (deliberate or inadvertantly), so if you have line of sight, you could use an IR remote.

Look on the web, I have some wireless remote controlled sockets that I bought a long time ago. The set that I have allowed control of 6 sockets with one remote, but each socket had to be switched on/off individually. Search for 'wireless controlled sockets'. They are a bit more expensive than your budget, but not too much.

 

[jcurrie]

what size motors (amp draw )?
jc

 

[sheffladreece]

Might not make much sense but the motor does not have to run at high speeds but slow and strong- say enough to pull a 1-2lb weight.

 

[jcurrie]

you diden't state amp draw but there is a system for controling model railroad loco's in G scale(1/23) called DCC that will handle over 1.5 amps.most systems have 200 address meaning they control 200 motors.
jc

 

[sheffladreece]

Sorry i didn't state the amp draw... Reason being im not too sure, Sorry... Although i will not be using the motors to power model railroads, the concept does seem to suit the situation that i have.... Having just had a quick look at the DCC controllers you mentioned and from briefly looking... Am i correct in assuming you would fit a decoder to each individual motor of which would then essentially control that motor and then you would control each individual decoder from the master DCC control unit ?

The ones i have viewed have been mains electric powered only... are there battery powered ones around ? and can the decoders also be battery powered ?

 

[jcurrie]

yes each motor would have a controler and the hand held units are portable the main unit is AC,the decoders run off of the supply voltage of the motor the wiring to each motor is asways hot the decoder turns motor off and sets speed.
jc

 

[shumifan50]

Model railway DCC is not suitable for your application from your desription for at least 2 reasons:
1. Simple cost. The DCC control units are expensive (much more tha £20. And so are the simple decoders - around £20 for cheapest ones.
2. DCC is a wired connection between the control unit and the decoders - the track is used as 'wires'.
3. And then you still need handheld controller to issue instructions.
4. If you just want to switch on and off, you will need an accessory decoder and these are also expensive - even a kit form controlling 4 accessories from MERG will cost more than £20.
5. DCC is fiddly when operating accessories with the cheaper controllers. The GUI ones cost more than £300 wwithout accessory decoders.
6. Although DCC support up to 1023 addresses on a single track, it will require many booster units as each controller/booster can typically drive a max of 4 amp.
7. Batteries are not an option on DCC as even the decoders draw quite a bit of current with motor switched off.

 

[sheffladreece]

Thanks for that shumifan50, after reading up on the DCC idea i have realised that this is not suitable for my problems... Is there any specific reason why no one has mentioned using either "bluetooth" or "zigbee" technologies ?

 

[(*steve*)]

zigbee seems very expensive, and you might be pushing it for bluetooth t get the distance you require.

It all depends on what you actually want to do. If you're going to build it yourself there are a heap of different technologies you could use. I'm fond of some small radio transmitters that operate on 2.4GHz.

However you're likely to need some experience with microcontrollers. Do you have that? The radio modules are a little over $US1, cheap arduino modules can be had for about $US3 Add to this a power supply, and something to switch the motors on and off. Not sure if you can do it under 5 quid per unit, but maybe.

Then you'll need a programmer, breadboards, programming skill, a PC, and something to do a final construction with (from matrix board up to design your own PCB).

The modules I've mentioned have some limitations in that they're generally used to set up channels between two nodes, so you'd probably have to use the network library to set up mesh (actually a tree) so you can communicate with more than 5 or 6, but that's not a huge deal.

 

[shumifan50]

I think you need to elaborate more on what you want to do:
1. What is the distance required
2. Is it possible to use line of sight
3. what is your level of experience with microcontrollers/electronics
4. what power sources do you have availableat the motor sites

The serious inpact on your implementation will be power supply:
1. power to drive circuit and motors will require significant amounts of power
2. power supplies are not cheap(considering your requirement of sub £5 slaves)
3. How portable must the whole solution be as batteries are expensive if large watt-hour are required.

 

[sheffladreece]

I think you need to elaborate more on what you want to do:
1. What is the distance required
2. Is it possible to use line of sight
3. what is your level of experience with microcontrollers/electronics
4. what power sources do you have availableat the motor sites

The serious inpact on your implementation will be power supply:
1. power to drive circuit and motors will require significant amounts of power
2. power supplies are not cheap(considering your requirement of sub £5 slaves)
3. How portable must the whole solution be as batteries are expensive if large watt-hour are required.

1. Stated in the original post i estimated around 50m... Upon reflecting this would probably be an overestimation and around 10-20m would be acceptable.

2. Line of sight is not applicable for this project.

3. No experience with micro controllers (not too sure what they are but research will be conducted following this post) and extremely basic knowledge of electronics i.e. I have previously worked replacing and repairing Laptop and Pc components.

4. The power source is planned to be battery operated possibly a rechargeable pack of some sort for both motor unit and remote unit.

The motors are not going to be operated for long periods of time. Basically turn on for around 1-2 seconds and turn off but have enough power to pull around 1-2lb of force.

Portability of the whole solution is one of its main characteristics.

 

[shumifan50]

Unfortunately I have no experience with RF, but it seems your budget will be low for what you want to do.