Motion sensor

[KevinW]

Is this the antenna at the upper right and can something be added to it to increase the range
slightly ?

 

[alec_t]

That looks like a printed bottom-loaded antenna. I'm no expert, but I think a full-length 1/2-wave vertical dipole antenna might improve things if you want an omni-directional response, or a Yagi array if you want a directional response.

 

[KevinW]

Thanks Alec.
That would be more than I require so I'll try relocating the base unit.
I was hoping I could add a small coil or something similar just to make it a tad more effective.

 

[alec_t]

I was hoping I could add a small coil or something

The existing antenna should have been dimensioned and loaded for optimum response already: adding anything would then de-tune it.

 

[dr pepper]

This is an arduino where I did something like this, this is a wifi device, so I was fortunate in that there is plenty of antenna's around for wifi frequencies, I just pinched one off an old router that already had a connector on the end.
I pulled the ant off the board and soldered on a socket, range is now 3x.
If your device is wifi you can do this, or you could build your own ant, but it can get tricky.

 

[KevinW]

That got me searching for 315MHz antenna's and they are available but did you disable the original antenna or add the new antenna to it?

 

[dr pepper]

I disconnected the built in ant, you have to do that.

 

[KevinW]

**broken link removed**
This might do it.

 

[dr pepper]

I wonder how that works, surely iy cannot rx and tx at the same time, must have a memory or something.

 

[Nigel Goodwin]

I would imagine it's intended for simple garage door remotes, so simply receives the small data packet and then retransmits it - it's probably fairly dependent on what's been transmitted.

 

[KevinW]

There seems to be more than one.
**broken link removed**

 

[KevinW]

it's intended for simple garage door remotes

Nigel, I think they were a companion to these