Hi! I have a problem, I recently aquired 2 LoRa RA-02 modules and 2 433mhz antennas for them.I power them using a dedicated voltage regulator thay outputs 3.3v, they are connected trough the NSS, MOSI, MISO and SCK pins to the pins 10, 11, 12 and 13 on 2 Arduino Mini Pro 3.3v boards, with "LoRa.begin(433000000)", I saw that if I changed it to 494000000 for example, the receiver doesn't receive anything. I set one as the receiver and one as the sender, the senders is working as it should, sending messages every 5 seconds.The receiver sometimes receives in bulk a lot of messages, incomplete like "he(?o" or messages that have no sense.And sometimes doesn't receive anything for some time.I expected it to receive a message every 5 seconds as they are sent by the sender but it doesn't even receive them correctly.I'm using the LoRa library by Sandeep Mistry alongside the examples for Sender/Receiver.
An antenna designed for 433 MHz won't work very well at 494 MHz.
And of course, both receiver and transmitter frequencies need to be the same. Was there some reason to change the frequency?
Well on the RA02 modules it says 433-525mhz, I tried changing it to 494mhz because I tought that the cause of my problems was the widely used 433mhz frequency.
433 MHz, in countries where it is legal, is for low power weather sensors, push button remotes, etc. Those have very short range and are very unlikely to be the cause of whatever problem you have.
As far as I know, 494 MHz is not legal for unlicensed transmissions in most countries.
Okay, then what could be the problem? I want to be able to send and recive signal to about 2-3km in air, so not a long distance.
Describe the problem and post the details. For hints and instructions, see the "How to get the best out of this forum" post.
Well I wrote the problem and given the details.
The first post describes attempts to transmit or receive at 494 MHz. That choice was a serious problem.
After reading the "How to get the best out of this forum" post, post the code for both transmitter and receiver, using code tags, for the trial with 433 MHz. Explain what you expected to happen, and what happened instead.
Well, I think there is no need to post the code, since it's a simple example and I mentined that, with the only modification being the frequency.
I described the problem, and told you that I expected it to receive the signals immediately after they are sent. But I recieve them in bulk after some time and they are incorrect.
Please read the article explaining how to use this forum and follow the instructions given in it. Until you change your mind about the information we need from you, we will not have enough information to understand the cause of your problem and will be unable to help you.
#include <SPI.h>
#include <LoRa.h>
int counter = 0;
void setup() {
Serial.begin(9600);
while (!Serial);
Serial.println("LoRa Sender");
if (!LoRa.begin(433000000)) {
Serial.println("Starting LoRa failed!");
while (1);
}
}
void loop() {
Serial.print("Sending packet: ");
Serial.println(counter);
// send packet
LoRa.beginPacket();
LoRa.print("hello ");
LoRa.print(counter);
LoRa.endPacket();
counter++;
delay(5000);
}
#include <SPI.h>
#include <LoRa.h>
void setup() {
Serial.begin(9600);
while (!Serial);
Serial.println("LoRa Receiver");
if (!LoRa.begin(433000000)) {
Serial.println("Starting LoRa failed!");
while (1);
}
}
void loop() {
// try to parse packet
int packetSize = LoRa.parsePacket();
if (packetSize) {
// received a packet
Serial.print("Received packet '");
// read packet
while (LoRa.available()) {
Serial.print((char)LoRa.read());
}
// print RSSI of packet
Serial.print("' with RSSI ");
Serial.println(LoRa.packetRssi());
}
}
These are the codes.
looking at the photos in post 1 is appears you are using Arduino pro minis as the host microcontrollers for the RA-02 modules
If I run
- your transmitter code of post 11 on a Pro Mini 3.3V and
- the receiver code of post 11 on a ESP8266 with the additional setpins() statement
LoRa.setPins(15,16,4); // for ESP8266;
if (!LoRa.begin(433000000)) {
the pro mini transmitter displays
LoRa Sender
Sending packet: 0
Sending packet: 1
Sending packet: 2
Sending packet: 3
Sending packet: 4
Sending packet: 5
Sending packet: 6
Sending packet: 7
the ESP8266 receiver displays
LoRa Receiver
Received packet 'hello 0' with RSSI -123
Received packet 'hello 1' with RSSI -122
Received packet 'hello 2' with RSSI -123
Received packet 'hello 3' with RSSI -120
Received packet 'hello 4' with RSSI -123
Received packet 'hello 5' with RSSI -120
Received packet 'hello 6' with RSSI -123
Received packet 'hello 7' with RSSI -122
Received packet 'hello 8' with RSSI -122
Received packet 'hello 9' with RSSI -120
Received packet 'hello 10' with RSSI -120
possibly power supply is the problem - try powering using USB FTDI breakout boards??
if you don't get the "Starting LoRa failed!" message the host microcontrollers are communicating with the RA-02 OK
The library you are using sets the TX power by default to 17dBm.
The legal power limit in a lot of places for the 434mhz ISM band is 10dBm. In addition for testing the boards set the power level to 2dBm, which will significantly reduce the power supply requirements.
LoRa.setTxPower(2);
Well I power them using a dedicated 3.3voltage regulator that can output up to 2A I think, power shouldn't be a problem....
How far apart are the devices when you are testing them? Are you certain that the data you receive was sent from your device?
if you don't have the serial monitor connected to check if the "Starting LoRa failed!" message is displayed or not how do know know the host microcontroller is connecting to the RA-02 modules correctly
once you know the modules are working you can then test with your 3.3V supply
They are pretty close, but I must say that I'm conducting the test indoors, but when it works it would be used in a countryside area, 2 km away from villages, etc. I think that some the data that I receive is sent from my device because it looks like a "hello", but is corrupted to say so....
I don't receive the "Starting LoRa failed!" message. And I have the serial monitor opened, and looking at the messages
I set it but I don't receive any messages now, the sender sends the messages 1,2,3,etc but the receiver just prints "Lora Receiver" and then doesn't receive anything.
the photos in post 1 show no serial monitor connection to the Pro Minis
how do you power the RA-02 modules? from the Pro Minis or a power supply
upload a schematic showing signal, power, ground connections etc
Edit: make sure you have a good ground connection between Pro Mini, RA-02 and any power supply