CheaperRFID - Other Uses

[Bill Brower]

Starting a new thread here as an offshoot of the CheaperRFID package.

As we come up with new ideas please post them here.

Thanks!

[Bill Brower]

Mailbox Signal

My first project will be to put a switch in series of the two batteries.

When the mailbox opens, it will broadcast.

[Bill Brower]

Security System Add-on

I figured this would also act as a good door monitor.

It could be used to monitor gates, windows, whatever.

Just wire a magnetic switch in series so the RFID will transmit under the conditions you want.

[Bill Brower]

40 Meter Board

This is the diagram on how I would hook a switch (either magnetic or manual).

If the normal position for the door would put the switch in an open position the batteries would last for a very long time.

[piperpilot]

Hey Bill, just a note that I posted on the other forum as well. I have been told by the manufacturer that a new version is coming out that has terminal blocks instead of batteries built in. It is much smaller and this will give you and easy way to add your switch. He is sending me a prototype this week. I'll take some pictures when I get it.

PiperPilot

[Bill Brower]

I need to get a potentiometer and wire it in series to 12v to see if I can use the pot as a voltage dropper, but make sure the series circuit still has enough current to power the board.

Normally resistors don't make good voltage droppers because if the load of the source changes, so does your voltage drop.

This circuit should be pretty consistent, maybe put a cap parallel to the load to keep the voltage up during the very quick xmt pulse.

[Jim Doolittle]

My first project will be to put a switch in series of the two batteries.

When the mailbox opens, it will broadcast.

I had a great mailbox announcer from Radio Shack (clearance price!) until I tried to automate it more. Messed up the soldering job and never got it to work again. I am ready to automate mailbox again though. I was going to try a HawkEye motion sensor and take advantage of both dusk/dawn sensor and motion sensor and never got around to doing it. Hmmm....maybe I need to modify DooMotion to account for both motion and light sensing which would equal mailbox opened. Or...I try this RFID idea...

[Jim Doolittle]

Garage Door Control

OK. We have two vehicles that are parked in attached garage. I would like garage door to open when they arrive. piperpilot mentions car power options that may be available. That is great! However, I have to come up with a different mechanism for opening the door because up 'til now I use X10 and I have a magnetic reed switch that disables ability for X10 to open door for security reasons. HomeSeer can close the door which I do if door is open for over 60 minutes with no movement by any of several motion detectors in the area (utilizing DooMotion features of course!).

What would anyone suggest?

[Rupp]

Jim,
This is the first thing I'm going to try. I'm going to allow HomeSeer to detect the RFID sensor and then try connecting a powerflash (or universal module - I can never remember which one will make contact closure when it receives and X10 signal) to my existing wires that the button is connected to. I know this isn't secure but I've not seen a stray X10 signal in months. A UPB device would probably be more secure.

[drozwood90]

Bill, every 2-3 seconds the load is going to change dramatically. You will have a tough time getting the time constant right for your "RC" that you are trying to make.

My suggestion is to just use a small power regulator. If you don't want a part like that micrel (which has a shutdown PIN, which would be connected to your Vin and your magnet switch, say a 10K to ground to make sure it gets pulled down when the contacts are closed) just use a diode with the reverse bias voltage that you want. That's all that is in most power supplies anyhow (just for the reference).

I'm not sure if a magnet switch is going to be able to turn OFF the voltage enough to give you what you want. I'd be interested in finding out!

If you need any help with a circuit, let me know. I design control boards for thermal imaging cameras for a living.

--Dan

I need to get a potentiometer and wire it in series to 12v to see if I can use the pot as a voltage dropper, but make sure the series circuit still has enough current to power the board.

Normally resistirs don't make good voltage droppers becuase if the load of the source changes, so does your voltage drop.

This circuit should be pretty consistant, maybe put a cap parallel to the load to keep the voltage up during the very quick xmt pulse.

[Jim Doolittle]

Jim,
This is the first thing I'm going to try. I'm going to allow HomeSeer to detect the RFID sensor and then try connecting a powerflash (or universal module - I can never remember which one will make contact closure when it receives and X10 signal) to my existing wires that the button is connected to. I know this isn't secure but I've not seen a stray X10 signal in months. A UPB device would probably be more secure.

I would likely move to a UPB UMI for this. In that case, I would remove the magentic reed switch that disallows (by breaking the circuit) opening of the door.

[Jim Doolittle]

Rupp,

See if this helps:

Powerflash -> Input
Universal Module -> Output

So, I think of PI (3.14159...) and then realize UM is O. Silly, but it works for me!

[anogee]

UPB U M I = Good
X10 = P O O !

[Jim Doolittle]

Hee..Hee!

[drozwood90]

Instead of a reed switch or some other mechanism to lockout the door, I wired 2 Universal Modules in series. Then, I have HS send both commands (it queues them and sends them fast enough). The Universal Modules are set for temporary closure.

Each module is a different house code AND number. So, IF I get a stray X10, worst case, it's going to trip only 1.

However, I'm currently moving to UPB, so as soon as I get some extra $$, I'll be going that route.

--Dan