Hi guys,

like in the title i ask you the easiest way to do that.

I have 2 Heltec Wifi lora esp32 with oled and sx1278 and they work fine, i have tested with success the WiFi_LoRa_32FactoryTest.ino, I would like with a raspberry to decide which text to send by heltec card with LoRa, and read it with another raspberry.

Raspberry(A)—>Heltec(A)—> ……………… by LoRa …………………. —> Heltec(B)—>Raspberry(B)

and viceversa

Raspberry(B)—>Heltec(B)—> ……………… by LoRa ………………… —> Heltec(A)—>Raspberry(A)

Thanks in advance for any suggestions, I enclose the code that runs on the heltec board, in raspberry i use python

but also java.

WiFi_LoRa_32FactoryTest.ino (by heltec):

#include "Arduino.h"
#include "heltec.h"
#include "WiFi.h"
#include "images.h"

String rssi = "RSSI --";
String packSize = "--";
String packet;

unsigned int counter = 0;

bool receiveflag = false; // software flag for LoRa receiver, received data makes it true.

long lastSendTime = 0; // last send time
int interval = 1000; // interval between sends

void logo(){
Heltec.display -> clear();
Heltec.display -> drawXbm(0,5,logo_width,logo_height,(const unsigned char *)logo_bits);
Heltec.display -> display();
}

void WIFISetUp(void)
{
// Set WiFi to station mode and disconnect from an AP if it was previously connected
WiFi.disconnect(true);
delay(1000);
WiFi.mode(WIFI_STA);
WiFi.setAutoConnect(true);
WiFi.begin("Your SSID","Your Password");
delay(100);

byte count = 0;
while(WiFi.status() != WL_CONNECTED && count < 10)
{
count ++;
delay(500);
Heltec.display -> drawString(0, 0, "Connecting...");
Heltec.display -> display();
}

Heltec.display -> clear();
if(WiFi.status() == WL_CONNECTED)
{
Heltec.display -> drawString(0, 0, "Connecting...OK.");
Heltec.display -> display();
// delay(500);
}
else
{
Heltec.display -> clear();
Heltec.display -> drawString(0, 0, "Connecting...Failed");
Heltec.display -> display();
//w hile(1);
}
Heltec.display -> drawString(0, 10, "WIFI Setup done");
Heltec.display -> display();
delay(500);
}

void WIFIScan(unsigned int value)
{
unsigned int i;
for(i=0;i<value;i++)
{
Heltec.display -> drawString(0, 20, "Scan start...");
Heltec.display -> display();

int n = WiFi.scanNetworks();
Heltec.display -> drawString(0, 30, "Scan done");
Heltec.display -> display();
delay(500);
Heltec.display -> clear();

if (n == 0)
{
Heltec.display -> clear();
Heltec.display -> drawString(0, 0, "no network found");
Heltec.display -> display();
while(1);
}
else
{
Heltec.display -> drawString(0, 0, (String)n);
Heltec.display -> drawString(14, 0, "networks found:");
Heltec.display -> display();
delay(500);

for (int i = 0; i < n; ++i) {
// Print SSID and RSSI for each network found
Heltec.display -> drawString(0, (i+1)*9,(String)(i + 1));
Heltec.display -> drawString(6, (i+1)*9, ":");
Heltec.display -> drawString(12,(i+1)*9, (String)(WiFi.SSID(i)));
Heltec.display -> drawString(90,(i+1)*9, " (");
Heltec.display -> drawString(98,(i+1)*9, (String)(WiFi.RSSI(i)));
Heltec.display -> drawString(114,(i+1)*9, ")");
// display.println((WiFi.encryptionType(i) == WIFI_AUTH_OPEN)?" ":"*");
delay(10);
}
}

Heltec.display -> display();
delay(800);
Heltec.display -> clear();
}
}

void setup()
{
Heltec.begin(true /*DisplayEnable Enable*/, true /*LoRa Enable*/, true /*Serial Enable*/, true /*LoRa use PABOOST*/, 868E6 /*LoRa RF working band*/);

logo();
delay(300);
Heltec.display -> clear();

WIFISetUp();
WIFIScan(1);

LoRa.onReceive(onReceive);
LoRa.receive();
}

void loop()
{
if(millis() - lastSendTime > interval)//waiting LoRa interrupt
{
LoRa.beginPacket();
LoRa.print("hello ");
LoRa.print(counter++);
LoRa.endPacket();

LoRa.receive();

digitalWrite(LED,HIGH);
Heltec.display -> drawString(0, 50, "Packet " + (String)(counter-1) + " sent done");
Heltec.display -> display();

interval = random(1000) + 1000; //1~2 seconds
lastSendTime = millis();

Heltec.display -> clear();
}
if(receiveflag)
{
Heltec.display -> drawString(0, 0, "Received Size" + packSize + " packages:");
Heltec.display -> drawString(0, 10, packet);
Heltec.display -> drawString(0, 20, "With " + rssi);
Heltec.display -> display();

digitalWrite(25,LOW);

receiveflag = false;
}
}

void onReceive(int packetSize)//LoRa receiver interrupt service
{
//if (packetSize == 0) return;

packet = "";
packSize = String(packetSize,DEC);

while (LoRa.available())
{
packet += (char) LoRa.read();
}

Serial.println(packet);
rssi = "RSSI: " + String(LoRa.packetRssi(), DEC);

receiveflag = true;
}