RF Receiver Range with Arduino

Projects General Guidance
1

I have been preparing the receiver using WS-RX-02 receiver and arduino Uno R3 board.
My connections are as follows.
3 GND PINS on RECEIVE UNITS are Connected to GND of ARDUINO

2 VCC PINS on RECEIVER UNITS are Connected to 5V on arduino

Data Pin on RECEIVER is connected to PIN 3 on arduino.

I have connected a simple wire of length 17cm as antenna on receiver unit.
I am using RCSwitch library to receive signal I am using my laptop to power the arduino.

I am trying to capture signals from one of my RF remote.

My receiver unit receives the singal only when I bring my remote very very close (about 4 to 5 cm close) to the Receiver unit. If i move it away then signals are not received by my receiver connected to arduino.

Why is my receiver range so short. How can i overcome the problem. Please help.

2

The range of the 433Mhz modules and remotes is much longer than that.

At least 10 m even through plasterboard walls.

Either your remote or your receiver is not working correctly

Are you getting useful data when its close to the receiver ?

3

Yes, I am getting the data in the Serial Monitor. I am using RCSwitch library and get below data when I bring my remote very close to the receiver.

Decimal: 5469376 (24Bit) Binary: 010100110111010011000000 Tri-State: FF01F1F01000 PulseLength: 215 microseconds Protocol: 1
Raw data: 164,552,348,676,664,176,316,580,656,176,688,200,192,264,92,92,420,232,636,660,228,636,232,616,244,636,240,620,640,228,616,244,1296,164,148,56,28,2296,584,84,32,404,668,196,228,16,500,240,244,

4

In that case it seems you have a defective (deaf) receiver, or your remote is defective

Have you tried replacing the battery in the remote transmitter ?

5

Thanks very much for your quick response on this.
I tested the remote with my switch and it is working perfectly fine with the distance of more then 20 Meters. Since remote worked properly with its own receiver switch so I assume there is no problem with the remote.

Other point is RF receiver receives the signal when I bring my remote very close to the receiver and data is also printed on the serial console. If I put a antenna (simple wire) having length 17 cm , range is increased a bit (but not more then 10 centimeters).

So, should I replace the receiver and try again? or what could be other issue with this.

Just another thing, would there be issue due to power supply from laptop? Moment I plug out my laptop USB and try with other power supply, my sketch stops working, looks like sketch is reset. Again I have to upload from laptop then it starts working but with very less range (as stated above).

6

Sounds like the receiver is defective.

Are you sure you have soldered the Antenna 17cm to the correct place on the board.

You would get 10cm range without an antenna (possibly more range)

I guess it could be supply noise, but it seems unlikely

Also confirm your supply voltage (these things normally take 5V)

Apart from that it sounds like the receiver is defective

7

Fine, I will check my supply and ensure it is 5 V.
I have soldered the antenna, i just used breadboard to attached the wire to the ANTENNA pin. Should I solder it? Just putting the wire into breadboard will create problem?

8

Its possible the breadboard is causing a problem, its is better not to solder a pin to the antenna, which goes into the breadboard

Unsolder the pin from the receiver and solder the wire straight onto the receiver.
Do not have the antenna connected to the breadboard in any way. This may be the problem

9

rahulopengts:
Just another thing, would there be issue due to power supply from laptop? Moment I plug out my laptop USB and try with other power supply, my sketch stops working, looks like sketch is reset. Again I have to upload from laptop then it starts working but with very less range (as stated above).

If this is an accurate description of the situation it seems strange.

The moment you unplug the USB cable the Arduino won't have any power so of course it will stop working.

But it should work just as well with another power supply. How do you know the sketch does not work?

It seems even more strange if the program needs to be uploaded again before it will work. The program should only need to uploaded again if you want to change it. Note, however, that when the PC opens the serial port the Uno will reset.

...R

10

@Robin2

I strongly suspect the issue is that the antenna pin of the module is going into a breadboard, which has enough capacitance reactance at 433Mhz to be effectively shorting the antenna to either GND or 5V

Also the breadboard has strips of metal in it, so the OP would have 2 antennas the wire and the metal track inside the breadboard

This doesnt sound like a good idea to me, as the metal in the breadboard will also be behaving as a partial wave antenna e.g 1/32 wave antenna and will interfere with the signal input on 433Mhz

11

Roger, I know nothing about antennas - it is a subject that has always seemed like magic to me.

However, regardless of how the antenna is connected I don't see how it could cause the Arduino to forget its program - which is one of the symptoms stated by the OP.

I suspect your good advice is likely to dissipate like smoke unless the OP provides a clear description of the problem.

...R

12

Based on your suggestion, I removed the breadboard and soldered the antenna wire directly to the PIN. With this range has increased to around 4 Ft. But it is not going beyond 4 ft now. My antenna is approx 17 Cm long.

Thanks for above suggestion.

What else can i try out to improve the range.

I am using RCSwitch, should I try out some other library to test the range?

13

Could you send us a picture of your Rx setup?

Try connecting the Rx ground together (there might be RF grounds and electric grounds). Same for the Data pins if there are 2. Same for VCC.

14

Is the pin from the antenna pad of the module still going into the breadboard?

You need to completely remove any connection between the antenna pub pad and the breadboard.
Can you unsolder the pin that is connected to the antenna, or remove the whole receiver from the breadboard and solder to it

15

Thanks to each on of your for your response.

I have made some changes as per suggestion.
I completely removed bread board and now connecting to arduino using jumber wires as can been in the attached picture.
Antenna is now soldered to the RX ANT pin directly.

Vcc from RX is connecting to 5V of arduino
DATA is connecting to PIN 2
GND from RX is connecting to GND of Arduino.
My arduino is powered by USB from Laptop.

I am still not getting the range. It works only when I bring my remote very close to RX (around 2-3 CM).

Could it be a problem due to my laptop?

Arduino_RX_SetUp.jpg
Arduino_RX_SetUp.jpg3264×2448 1.9 MB

16

It may be that either the transmitter or the receiver is incorrectly tuned. You could try tweaking the receiver coil for maximum signal.

17

Is it possible there is some external RF interference? Have you tried moving the whole project to a different location?

...R

18

Measure the voltage on the receiver board.
Needs to be very close to 5V .
If the voltage is low , (less than 4.9 V) the receiver will appear to be deaf.

19

The problem of loosing the sketch on plugging out USB and Plugging in USB has been resolved. Arduino is retaining the sketch.
Problem was due to my code which has references to Serial.println. Moment I plugged out the USB and plugged it back to laptop, Serial port connectivity was lost and my code did not work after connecting back the USB.

I removed the code for Serial port and after this reloading of code was not required!

But I am still struggling with range.

Today I got the new power supply 9v DC and used this to power my arduino (earlier I was using laptop). The range did not increase even after this.

  1. Should I power the receiver with separate power supply? I mean, should I connect the VCC and GND of receiver to another new power supply and do not connect this to arduino pins. ONly data pin of receiver would be connected to arduino?

Also, tomorrow I am going to get voltmeter to check the voltage at receiver pin.

Thanks all for your help so far.

20

ALWAYS connect grounds together.

If the receiver is powered by a clean, minimally noisy 5V power source, the power supply is not the problem. Try a different receiver.