Cheap RFID presence hack

[rsisson]

a long time ago, three houses ago to be precise, I hacked together a poor mans RFID to detect my car.
i used a 433 transmitter hacked to transmit a "ping" about every 2-5 seconds when it was powered up.
This was powered by my cars ignition, so if my car was on, it took about 2-seconds to "find"
i then used the HS2 433 Oregon receiver and all of its triggers to detect my car, and much more.
combined with a directional driveway sensor, and some complicated logic, I could determine if my car was coming or going and what I should do at that time... it was a RubGoldberg hack, but it worked and was reliable for several years...
Then I moved...

i am am where I might try again... but I can't find the TRANSMITTERS again. They were from England and were tiny cheap things that were purpose built for me, but were still only $8 each for 5.

Anyone have any any ideas who they were from, or a good substitute?

i thought about Bluetooth, but it doesn't have the range or acquisition time... 433 gives me good range, and detection, because it is dumb, it is FAST.

thoughts? Ideas?

as I wrote, this was cheap, it used the Oregon weather radio receiver, had good range, close to 100', and it was fast... and yes it was hack...but it worked

[Uncle Michael]

Have you tried a web search for 433 MHz transmitter? I just found s bunch of cheap options like this:
https://www.amazon.com/SMAKN%C2%AE-4.../dp/B00M2CUALS

[rsisson]

Done a number of searches... most of the transmitters I found are tied to a specific receiver as a control kit (RC or garage door) or are raspberry pi based....
The ones I had might have been pi based, but they had been flashed by the time I got them to only do one thing... send a ping with a serial number every 2-5 seconds based on the jumpers on a header. That was it. The Oregon receiver would then get the packet and send it to HS2 and some "interesting" logic would figure out what was going on based on other sensors... All I added was a 9-12v supply and I was done. It would ping ever 2-5 seconds as long as it was powered up. Really simple, dumb, and functional.

[Richel]

Done a number of searches... most of the transmitters I found are tied to a specific receiver as a control kit (RC or garage door) or are raspberry pi based....
The ones I had might have been pi based, but they had been flashed by the time I got them to only do one thing... send a ping with a serial number every 2-5 seconds based on the jumpers on a header. That was it. The Oregon receiver would then get the packet and send it to HS2 and some "interesting" logic would figure out what was going on based on other sensors... All I added was a 9-12v supply and I was done. It would ping ever 2-5 seconds as long as it was powered up. Really simple, dumb, and functional.

Check out https://www.ananiahelectronics.com/

[rsisson]

Yup,those look like what I used, but not what I paid.
Mine were sub $10 ea.
Functionality is right... ping every 2.5 seconds...
40 meters for the high power unit is about right, at the end of the driveway...

my logic looked at to see if the garage garage door was up and which way the driveway sensor said the car was going to determine what to do.
incomming and door closed implied I was coming home
outgoing and door open implied I was leaving
in without my car was a guest
out without my car was likely my wife or a guest leaving.
my car without driveway motion and door closed was me in the garage starting the car
and so on...
if I went 10 seconds (4 cycles) without a ping I knew I had either turned off the ignition or gotten out of range...

[Richel]

Yup,those look like what I used, but not what I paid.
Mine were sub $10 ea.
Functionality is right... ping every 2.5 seconds...
40 meters for the high power unit is about right, at the end of the driveway...

my logic looked at to see if the garage garage door was up and which way the driveway sensor said the car was going to determine what to do.
incomming and door closed implied I was coming home
outgoing and door open implied I was leaving
in without my car was a guest
out without my car was likely my wife or a guest leaving.
my car without driveway motion and door closed was me in the garage starting the car
and so on...
if I went 10 seconds (4 cycles) without a ping I knew I had either turned off the ignition or gotten out of range...

Good. My transmitters are powered by the car's AC outlet using a converter for the low-voltage DC. I use virtual devices to determine if a car is coming or going [(e.g., if Ford (RFID) goes out of range and if Ford (virtual device) has been home for more than 5 minutes, close garage door and set Ford (virtual device) to away. The reverse is if RFID comes into range and Ford has been away for more than 5 minutes, open garage door and set Ford to home]. This works pretty well, but sometimes gets out of phase.

[rsisson]

I had a directional driveway detector that kept things in sync along with being able to check if the garage door was actually open or not...

dont have a garage door anymore, but I am trying to lock/unlock my entrance door along with some lights...

i had more "play money" back then, and things have gotten more expensive, so I don't know if I will rebuild or not...

depending on what router you have, you may be able to trigger off the presence of your phone/tablet as well for validating home/away....

some routers talk to ifttt, which talks to HS3...

1 router ago, I had it set to unlock the front door when it saw my phone come into range, but the delay was significant, so my key was often faster... but confirming you are out of range when No ford AND No phone would be a way to stay in sync.

[Richel]

Thank you. I like your suggestion, which I will look into implementing. I think my security system has a geofence feature. Also, I have SyncUp with T-Mobile in the OBD port that definitely has geofencing. However, SyncUp, a product of Mojio, is very primitive when it comes to interfacing with other systems. Elliott

[Pete]

Here continue to utilize the old cheaper RFID devices in the headliners adjacent to the dome lights. Years now and still functioning. Simple and functional.

I went to having one receiver unit (serial) with an antenna (old Radio Shack multiple frequency monitor antenna) in the attic. (now it is the same one being used for the W800).

I use the devices as an announce feature but not much else these days.