Hello, i have 2 arduino uno boards and 2 lora ra-02 sx1278 modules
i am trying to send message from uno 1 to uno 2 and then to get feedback message from uno 2 to uno 1
is that possible and if it is, how to do that?
just need a simple sketch
thanks
The UNO is not a good choice for use with the RA-02.
The UNO is 5V level logic and the RA-02 is 3.3V level logic so you would need to add logic level conversion circuits for the connections between the UNO and RA-02. The UNO cannot really provide enough current for the RA-02 on its 3.3V supply pin so a 5V to 3.3V regulator is required also.
Much much much easier to use 3.3V logic level Arduinos or Micro controllers with the LoRa module.
Most of the LoRa libraries will have simple transmit and receive examples.
@srnet thanks for your updata....yes i am using 3.3V pin on uno and i got message hello on other side but (master to slave) but feedback (slave to master) is not possible or it is with lot of noise...so you are telling me to try using voltage divider if i am using uno, or to change to nodemcu or nano....
can you provide me sketch for this reversal communication master to slave and then slave to master?
Who knows what the problem might now be?
If you have not used logic level conversion, your LoRa modules might now be damaged.
Check the examples folder in the LoRa library you are using, you did not say which one, there could be reverse communication examples there.
i am using 3.3V pins and library
there are 2 lora modules...when i upload sender code and receiver code from master to slave it works good (sending message and receiving message) but when i upload code vice versa (slave to be master and to send message) receiving messages is full of noise...
what does it mean? where is the problem in lora sender or lora receiver
If the send and receive examples work one way, but not the other it could be that one module is damadged.
Show us a picture and schematic of the wiring.
this is project i am following and i just wanted to add feedback from receiver to sender
Which shows the Adafruit RFM95 modules that have a built in regulator and 5V to 3.3V logic level conversion, so can be connected to a UNO.
But you said you are using the RA-02 ?
the video in the link of post 8 shows an RA-02
and code using the LoRa.h library
seems to be some confusion in the original tutorial apart from directly connecting a 3.3V logic LoRa module to a UNO host which uses 5V logic??
EDIT: as @srnet states the diagram is referring to Adafruit RFM95W LoRa Radio Transceiver Breakout modules which have onboard 5V to 3.3V level converters?
Yes I am using ra02 sx1278 modules
this is a simple LoRa chat program where text entered on the Serial monitor keyboard is transmitted over LoRa P2P
code for UNO (you will need to change frequency)
// simple LoRa chat program using RA-02, RFM95, etc
#include <SPI.h>
#include <LoRa.h>
void setup() {
Serial.begin(115200);
delay(2000);
Serial.println("\nLoRa Chat program");
LoRa.setPins(10, 9, 2); // 10 for UNO and Nano, 53 for Mega
//LoRa.setPins(15, 16, 4); // for ESP8266
//LoRa.setPins(8,4,7); // for Lora 32u4
//if (!LoRa.begin(433E6)) {
if (!LoRa.begin(866E6)) {
Serial.println("\nStarting LoRa failed!");
while (1);
}
Serial.println("\nLoRaChat started");
}
void loop() {
// if packet received from LoRa read and print it
while (Serial.available() == 0) {
int packetSize = LoRa.parsePacket();
if (packetSize) {
while (LoRa.available())
Serial.print((char)LoRa.read());
Serial.println();
}
delay(10);
}
// if keyboard text entered read and transmit it
if (Serial.available()) {
char outgoing[50] = { 0 };
Serial.readBytesUntil('\n', outgoing, 50);
Serial.print(" My Station: ");
Serial.println(outgoing);
LoRa.beginPacket();
LoRa.print(outgoing);
LoRa.endPacket();
}
}
UNO output
LoRa Chat program
LoRaChat started
My Station: test 1 hello from UNO
My Station: test 2 1234567890
hello from 32u4 test
test 2 from 32u4 0987654321
Adafruit Feather 32U4 LoRa output
LoRa Chat program
LoRaChat started
test 1 hello from UNO
test 2 1234567890
My Station: hello from 32u4 test1
My Station: test 2 from 32u4 0987654321