The spec sheet claims an eight-foot range. The most I got was six feet no matter how far I stayed from local interference.
One thing to try is to have the transmitting devices spend most of their time asleep, only waking up to transmit a signal.
Would it be OK if the lights sort of smoothly rise as the devices approach each other,
A theoretically perfect isotropic radiator does that (Isotropic radiator - Wikipedia, the free encyclopedia ) but I don't think they can be built in practice. Antennas all have characteristic radiation patterns which are affected by the shape of the antenna and what is near them.
That would be perfect!
If that could happen, I would be completely and totally happy! It's exactly what I wanted them to do, but was thinking I needed to have that done by the microcontroller.
heh heh...from then you lost me.
I need to read up on RFID....
So you're saying if I used a RFID, then it would be basically an "ON" "OFF", but if I used something to "test" the strength....what could do that...cause THAT sounds perfect to me!
EDIT:
If I'm getting you right....the receiver would basically have "steps" or something and notice when it hits a signal of a certain strength...if it detects that, it stays off, but as it gets closer it realizes the strength of the signal is coming with more intensity, so it starts to light up?
In all I think it could be an interesting but possibly fairly complex task.
I have to say that i dont agree. There are several antennas that are omnidirectional that have spherical transmissions. think of walkitalkies (beeing a radioamateur i have made a couple of these antennas). If you use a GP (Gground Plane) antenna then you get full 360 deg and 180 deg vertical. But there can be issues with the power and where you put the antenna that can do stuff you havent anticipated.
The walkitalkies (and GPs) are just a vertical like the one on a RC controller, and my allegation is that they are "true" omnidirectional antennas.
Up and down are still a problem.
Torben said:Only approximately. Up and down are still a problem. The radiation pattern is more toroidal than spherical. I don't think a true spherical radiator is really possible to build.
There will of course be a littel cone going from the antenna,
Well Torben isent the point here to "see" when a device is in range? with antennas you can get the device to fade the light on as the signal increses.
Im not shure what you men by up and down (but if i get it you mean the vertical line of the antenna) and by the way the down will bw limitet by the ground plane. There will of course be a littel cone going from the antenna, whit the center in the vertical (follow the length of the antenna) line and going on for ever. but from my experience with radios (espcialy handhels units) you can get a nice signal even if you point the antennas at each other (tip to tip)
I'm no expert, but I am sure there are dead spots above and below, but as Kryten said, the ground eliminates one of them, and the top...well, in this case, it's not a big deal as they're not going to be "stacked" on top of each other. If I can get an 80 radius out of the antenna..with the majority of the signal in a 360 degree radius out from the center of the device, then that gets the ol' thumbs up from me.
So....lets see here. Are we perhaps under the agreement that this may work with this method?
as for the RF .. torben, I'm not sure that on 30cm distance "radial vs toroidal" would make much difference .. if it was 30m then it would be much more important ... for 30cm, I believe the whole different problem's arise..
crazylegsmurphy, reed relay will "on/off" depending on magnet near it (the idea is to use it as a switch "actor" will use when he want to turn them on ... does not go with your requirement (detect proximity) ..
how to detect signal strength with few cm precision
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?