Thanks, I’ll try and take all that in

 

Hi Eric, I hope you don’t mind me picking your brains? As you’ve probably worked out, I am firstly going to try and boost an existing wireless motion sensor and receiver by soldering a new wire antenna to the receiver first! Here is the receiver in the photo. The antenna is in the top right corner but it is soldered at both ends ( hence the confusion ). You said to remove the old one but now you know the layout, please can you advise whether to remove it totally and where to solder the new antenna as pictured?

 

Can a 433 transmitter and receiver set be bought pre-coded ? This would save the need of programming Arduino's !

 

hi,
I will try to find the 433MHz TX/RX pair in my stock, let you know if there is an easy way to attach an antenna.

What do you mean by by precoded for the basic type of the 433MHz TX/RX.?
The HC12 uses RS232 format for input/output data, this means a simple MCU.

Post more details regarding the specification of the project, there maybe alternative ways of getting the desired result.
E


Update:
Can you post a photo of the back of the PCB, showing the Antenna wire ends.???

 

hi Bm1,
Attach 433MHz antenna to the pads shown in these images.
Also attached aPDF showing how to use and Arduino with 433MHz moduless.
E

 

What I meant was if it was possible for the tx and Rx to come pre loaded with the sketch codes but I’m assuming they don’t?
Before I take on building my own wireless driveway alarm set up, I wanted to add/boost the antennas and see if I can get a better range with the wireless motion sensor transmitter and separate receiver that I already have! Usually there are, as you have shown the little antenna holes in the corners of the tx and rx modules but as I have shown you the ones I have are different so was asking how to achieve this on my set? Thanks again. Ps. When I do build my own, I shall probably take your advice and use the HC-12 modules you recommend for better range!

 

On the transmitter it looks like the wire loop and the etch on the transmit board form the antenna. (Or the etch is part of the matching network to the antenna.) It looks like it is a very simple transmitter whose frequency is controlled by the HD433M SAW resonator. The actual frequency is only controlled within about a 1 Mhz window so the receiver bandwidth will have to be quite wide which tends to make it less sensitive. You are providing almost no information that will help us advise you. Can you supply the following information. The FULL documentation on the remote sensor and receiver (Or the alarm system it is designed to be used with.) How much you want to extend the range and what sort of terrain is between the transmitter and receiver. Trees and buildings will attenuate the signal so the antennas may need to be mounted high up. If you only need a small improvement in range then a simple dipole or ground plane antenna may solve your problem. (Note a quarter wavelength at 433 Mhz is about 690mm.)
Edit, I have just seen your post #26 and a possible solution (Depending on the length of your driveway.) may be to use one of the remote control unit sold on Ebay and by Banggood such as this.
Les.

 

Hi Les, I have the wireless Digiteck b2 door/driveway type motion sensor alarm. The sensor is battery powered and the receiver is mains powered. Please see picture attached.
Yes, I think you are correct in the fact that the sensor antenna is that loop/part of the trace and the receiver has the 1 inch wire in the top right corner! This all worked fine from inside a shed to just inside the window where the receiver was about 30 meters away but now i have the receiver in a different room in fact closer to the sensor, about 22 meters apart now but it’s not working now! I don’t need to use remotes!
I hope this helps

 

the ones I have are different so was asking how to achieve this on my set?

That may be tricky. The linear antenna in the first pic in post #22 has a single-turn coil alongside it, labelled TC1. I'm guessing the 'TC' stands for Tuning Coil. As coil and antenna are electromagnetically coupled, changing the antenna may well affect the tuning. You won't know until you try.
Is the existing antenna wire electrically connected to other circuit components at both ends, or is one end unconnected (apart from being anchored to the pcb)?

 

Hi Alec, I took your advice to try, I soldered a 173mm straight copper wire antenna to the existing receiver antenna and the results are much worse! I don’t know if it’s because the total length of the antenna needs to be a curtain length, I do think there is some power getting to the original antenna too!

 

I don’t know if it’s because the total length of the antenna needs to be a certain length

A tuned monopole antenna would normally be 1/4 wave-length (173 mm for 433MHz), but you would need to allow for any existing wire length, and how it's terminated.

 

I can’t understand why a wireless motion sensor and receiver suddenly looses its range, it only works when you’re in the same room? I’ve tried it in open air too!

 

hi Bm1,
What sort of range outside are you aiming for.?
E

 

Well it used to work fine at 20 metres and more, I can’t see what might suddenly go wrong! I would like to understand why as I am interested in the workings of these things! Im a mechanic and I look at it as if it used to work and still does albeit at a shorter range, what could have changed

 

hi,
Are there any changes you have made since it worked at 20mtrs.?
If its battery powered transmitter, is the battery OK, etc.
E

 

I can’t see what might suddenly go wrong!

Some cheap wireless Txs, such as those in typical wireless doorbells, are not crystal-controlled and can drift off frequency, sometimes to the point where the Rx no longer responds. The drift is likely the result of moisture absorption in the Tx pcb (generally SRBP rather than epoxy-glass).

 

No distance change and the batteries are new! I shall try to research what crystal controlled tx and rx means. I can’t control the moisture but I’ve taken on board these points for when I build a set!

 

I shall try to research what crystal controlled tx and rx means.

Tx = transmitter, Rx = receiver.

 

Yes, I mean the crystal part of it!

 

To make a wireless motion sensor tx and rx can a crystal controller be used, what frequency can be used, not 433mhz I suspect?