Hi, first i wanted to make a simple car door opener using RFID, but the distance was too low, no hobby RFID module with more then 10 cm, so i passed it and went to bluetooth, witch isn't good as well, beucase i don't wanna depend on my phone or others.
So i went to RF modules, the receiver part is easly done but the important part is the transmitte.
I want to make a Key Chains as small as possible and as low battery consumation as we can.
The thing is that i don't want any buttons, i only one signal that is sended every 1 sec or so and when I approach the car it will detect is from max 3 meters and open the door
So, what do you guys think ? Is this possible ( i'm only referring to the transmitter part )
How ?
The reason they have buttons on commercial key fobs is that xmitting eats batteries. And a six month battery life would be an open invitation to get burned at the stake (in a commercial application).
if this is a school project, it is a brute-force solution, good for proof of concept. If it is hobby or commercial project, I would suggest going back to the drawing board (and erasing what you got so far).
The thing is that i don't want any buttons, i only one signal that is sended every 1 sec or so and when I approach the car it will detect is from max 3 meters and open the door
How are you going to keep the door down when you get the car in the garage?
TomGeorge:
Hi,
If you have the Tx transmitting every second, ALL the time.
When you get in the car, the door will always want to open.
Also how are you going to close the door when you leave the car?
Please define "door opener"? Or do you mean "door lock"?
(Sorry about previous post, early morning , not enough coffee..., for some reason thought you were applying it to garage doors.)
Thanks.. Tom...
No prob.
And yes, I mean door locker and Unlocker and I also have a relay in my central locking witch tells me if the car is locked or not also I'll include some spamming preventions like when you enter the unlocking range the system will wait some time(like 2 sec) before doing it again, as I said the receiver is not a big deal, the really big problem for me is the transmitter and how can I build it small and power saving
Don't want any buttons.
Wants to lock and unlock.
Wants to spam signal.
Wants long battery life.
Doesn't want to spam signal.
Impatient.
Don't bump your own post when not even a full day has passed. Or ever.
Your car must not be worth stealing if you're entrusting its security to something you make.
If you can't find any info about active rfid, then you're too incompetent to make a security device. If you're penny pinching on a device that will secure a car, then you're literally penny wise, pound foolish.
INTP:
Don't want any buttons.
Wants to lock and unlock.
Wants to spam signal.
Wants long battery life.
Doesn't want to spam signal.
Impatient.
Don't bump your own post when not even a full day has passed. Or ever.
Your car must not be worth stealing if you're entrusting its security to something you make.
If you can't find any info about active rfid, then you're too incompetent to make a security device. If you're penny pinching on a device that will secure a car, then you're literally penny wise, pound foolish.
Tnx for replay but your post doesn't help me in any way, it isn't an advice either so is useless to me or anyone who will read this topic in the future
The advice was to not spam the forum by bumping your post. Some people won't bother helping rude, impatient people like you.
Other advice was to try harder to find info on active rfid since the info you claim isn't there, is there.
You're fussing over how to make a tiny transmitter that is going to send 86,400 transmissions a day, on a battery, and you want it to last. Daft.
You're dealing with a car. A car that has a massive battery that gets recharged as you drive. It's a power source you can rely on for this project. Put the active RFID reader at the car, and the tag on you. You won't find any tinier thing to carry and a longer lasting setup than that. It will basically last forever. Your car will die before the rfid setup does.
So stop going on about advice being useless and asking for other advice as if you are ignoring all of the information already given, as if you are waiting for someone to completely do this project for you and only then will you be happy.
Nobody wants buttons to remote car lockers, but there-s a good reason they still have it.
A RF device that sends the unlock code every second will consume in a day the same battery capacity a button operated key lock will spend in a year, opening & closing the remote lock 100 times / day.
