Hi everyone !
I have Arduino uno R3 that I want to use with a keyfob to create an alarm system for car, however I couldn't get the responsive range beyond 3 meters .The RF receiver can use 12v power supply to get a range of 100m as the datasheet claims, but when I connected the module to the 12c power supply while keeping the data pin connected to Arduino board the Arduino can't detect the signal anymore. Anyone can help please understand what more can be done to extend the range beyond 3meters knowing I use antenna of length 17.3 cm?
Do you suspect the problem is with your keyfob? 3 meters range is pretty good for such a device.
Greetings!
No, I don't think it's the keyfob because the arduino is responding consistently to the locking and unlocking signal from the key within 3 meters after 3 meters the response stops. I want to hook the receiver module to an external 12v power supply because the datasheet says it can take up to 12v and the higher the voltage the higher the range but it didn't work when I connected the 12v power supply to the receiver module so I don't know where to go from here?
First of all your GND between arduino and receiver(PSU) have to be connected .
Second, what is the voltage of data pin from receiver, can arduino handle it?
Third, it's not guaranteed that you get better range with 12v. For transmitter yes, for receiver...maybe.
Also, 0.5cm more or less on antenna length can make noticeable difference.
On cheap modules, then yes it can be a noticable differance.
Problem is that you dont know wheter its 0.5cm more or less.
Cheap modules use cheap components so they probably wont be that accurate. So whilst the circuit might possibly be designed for a 50R impedance, that might not be what actually happens. And it can vary between different modules of the same type.
On cheap modules its unlikley to be important to keep antenna wires to an accurate 1/4 wavelength.
If you know how you can tune the length of antennas on cheap modules and in my experience you might improve radiated power by 3dBm or a bit more.
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Thanks for the reply but I tried already connecting both grounds (of the 12v and ardunio) it did not work. It's getting weird. Will making a different antenna design be helpful in this way
Are you talking about reception improve of 3dBm or transmission here?
Sorry ?
Does the antenna 'know' its being used for transmission or reception ?
I'm not sure but I thought the module itself amplifies the signal so if the signal is weak already it needs a more powerful amplifier not a longer wire as I think it works, is this right?
There is ALWAYS noise along with the signal. Amplifying both happens, so nothing is gained. The amplification adds it's own generated noise.
If the antenna is a 1/4 wavelength of wire and the rest of the circuit board and wiring make another 1/4 wavelength, then that is very best you can hope for. Any longer or shorter antenna mages reduced transmitted power. The antenna must be close to resonance at the frequency you are transmitting.
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I agree
Did I miss something, I have no idea what receiver /transmitter is used here..??
Cheap or expensive..., no idea.
CC1101 or some hand soldered rx board?
Did it give 12V data to arduino?
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