RF Power Detector with LT5534 - Phone proximity detector

Using Arduino Sensors
#1

Hello I have been trying to follow the set up of the thread here to connect a RF detector to an arduino.
The data sheet could be found here.

However, my analog reading stopped after 1 sec. At the moment, I am still waiting for the chip antenna to arrive and I have been told it should receive some readings even without it. Hence, I wonder if my circuit wiring (which you could find in the attachment) or my code went wrong, and it would be amazing if someone could provide me with some advice.

Cheers,
Karen

My code is super simple:

void setup() {
  Serial.begin(9600);
}

void loop() {
  int sensorValue = analogRead(A0);

  Serial.println(analogRead(A0), DEC);  
  delay(1000); 
}

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#2

What happens when you read the output of the 'detector' with a multimeter, does the voltage change when there is a transmitter nearby ?

#3

Do you have a cell phone nearby? Is that what you are listening to? They only transmit when necessary, otherwise they are silent so other phones can use that channel.

Paul

#4

Paul_KD7HB:
Do you have a cell phone nearby? Is that what you are listening to? They only transmit when necessary, otherwise they are silent so other phones can use that channel.

Paul

I do have a cellphone nearby. Are you suggesting that there will only be readings if the phone is active (making a call/texting) please?

I too have a concern that my wiring to the arduino is possibly wrong... which you can also find in the attachment of the first thread.

Cheers,
Karen

#5

srnet:
What happens when you read the output of the ‘detector’ with a multimeter, does the voltage change when there is a transmitter nearby ?

Hello, the voltage didn’t change.

#6

cklkaren:
Hello, the voltage didn't change.

Then it looks like the sensor is not doing what you expect it to.

#7

cklkaren:
I do have a cellphone nearby. Are you suggesting that there will only be readings if the phone is active (making a call/texting) please?

If the phone is not actually active as a transmitter as in making a call, downloading from the internet etc, there is not a lot to detect.

#8

cklkaren:
I do have a cellphone nearby. Are you suggesting that there will only be readings if the phone is active (making a call/texting) please?

Yes. Especially when the call is coming in - extra power, which will normally be dialed down. That's what those ringer lights of 10-15 years ago worked with. It's been a long time since I've seen them, also a long time since I heard the characteristic distortion of a phone signal picked up by a radio. Modern phones probably use less power.

Also there are intermittent very short transmissions to keep the phone connected to a nearby mast. You may be able to pick up those as well.

The rest of the time the phone's transmitter is sleeping. Not just to clear the channel, it also saves a lot of power.

#9

cklkaren:
I do have a cellphone nearby. Are you suggesting that there will only be readings if the phone is active (making a call/texting) please?

I too have a concern that my wiring to the arduino is possibly wrong... which you can also find in the attachment of the first thread.

Cheers,
Karen

A cell phone is only active if the received signal goes away, then it hunts for another connection on another channel. That means it will be transmitting intermittently until it either gives up or finds another connection.

Otherwise your cell phone is silent until you tell it to do something, or it receives something addressed to it specifically, like a text. Then it will briefly acknowledge it.

Paul

#10

cklkaren:
Hello I have been trying to follow the set up of the thread here to connect a RF detector to an arduino.
The data sheet could be found here.

You have 4 red wires going into separate strips of the breadboard, doing nothing - is that what you intend?

#11