Hi all,
Im not 100% if I am posting in the correct subsection but I think the problem is in just the sensor(receiver) part.
I am doing a project where I want to control some 433 ac outlet switches in my home.
So i bought one of these kits : https://www.electrokit.com/en/product/rf-link-433mhz-transmitter-and-reciever/
It was simple enouth to hook up both to two arduinos unos and tried sending some data between them which worked fine.
The problem is when I try to read the 433 mhz signal from remote control. I have used RCSwitch library to detect the signal and just thougth the protocol wasn't supported. But when I tried this code:
bool state = false;
bool newState = false;
int start = 0;
int last = 0;
int timer = 0;
void setup() {
Serial.begin(9600);
pinMode(2, INPUT);
}
void loop() {
newState = digitalRead(2);
if(newState != state){
last = start;
start = micros();
timer = start - last;
state = newState;
Serial.print(state);
Serial.print(" at: ");
Serial.println(timer);
}
}
I expected to se some kind of time difference when I use the remote but it detects nothing. I know the code is crap but when I try it with the transmitter from the kit it works.
When no signal is sent it prints something around 14000 all the time but when i send something with the transmitter I get:
1 at: 14604
0 at: 14460
1 at: 15368
0 at: 13664
1 at: 23792
0 at: 356
1 at: 4420
0 at: 316
1 at: 2720
0 at: 320
1 at: 3820
0 at: 13080
1 at: 14600
0 at: 14520
1 at: 14572
Clearly something is outputted. But when i use one of the rc remotes, nothing happens. I even digged up another rc system from another brand but nothing. Both remotes says they are running on 433.92 mhz and i have tried with different antenna length by attaching jumperwires to the receiver.
I just need help to at least detect a signal so I can start working with repeating it.
Begin your research by getting an SDR, Software Defined Receiver, from Ebay or other source. It is a dongle plugged into you PC USB port. The PC software will let you see what is on the frequencies you choose and then you can determine the type of modulation used by the transmitters you are interested in. They are really cheap and they do work.
Paul
Two transmitters using the same frequency do not necessarily use the same protocol/modulation. Carrier frequency is just one of several wireless transmission parameters.
wvmarle:
Two transmitters using the same frequency do not necessarily use the same protocol/modulation. Carrier frequency is just one of several wireless transmission parameters.
And by law, each transmission is just a few milliseconds long.
Paul
Paul_KD7HB:
Begin your research by getting an SDR, Software Defined Receiver, from Ebay or other source. It is a dongle plugged into you PC USB port. The PC software will let you see what is on the frequencies you choose and then you can determine the type of modulation used by the transmitters you are interested in. They are really cheap and they do work.
Paul
I Have researched SDR's and that may be helpful, thanks for the tip. I found one to buy in Sweden, https://www.electrokit.com/en/product/rtl-sdr-receiver-dongle-v3-2/
(RTL-SDR receiver dongle (v3))
It should be compatible with the with the frequencies and are not to expensive. But do I need to buy seperate antennas to it? And do they need to be made for 433 mhz or are there any universal?
MarkT:
Those cheap modules you got only do OOK, so FM, PM, QAM, or pretty much any other modulation scheme is invisible to them.
wvmarle:
Two transmitters using the same frequency do not necessarily use the same protocol/modulation. Carrier frequency is just one of several wireless transmission parameters.
Ahh so my reciever might not use the same technique to communicate. I will then try to research what mine could use or something. That may be the answer I was looking for. I got stuck when I couldn't even detect the signal and my google skills was not enough apparently. There is just so much to learn! Thanks, I will do an update if I find something.