From efd381561ade9aef53f454584e807409dd924537 Mon Sep 17 00:00:00 2001
From: Th3maz1ng <re.hertz@laposte.net>
Date: Tue, 28 Oct 2025 19:27:15 +0100
Subject: [PATCH] Modified the quick and dirty firmware to add the support for
 a LoRa module (RFM95W). This is a poof of concept and needs to be refined.

---
 src/app/app.ino | 75 +++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 66 insertions(+), 9 deletions(-)

diff --git a/src/app/app.ino b/src/app/app.ino
index 617a96d..6a45635 100644
--- a/src/app/app.ino
+++ b/src/app/app.ino
@@ -9,10 +9,11 @@
 #include <PCF8574.h>
 #include <HttpClient.h>
 #include "RF24.h"
+#include <LoRa.h>
 #include "definition.h"
 #include "credentials.h"
 
-
+/* NRF pinout definition */
 #define NRF_1_CE 15 //chip enable
 #define NRF_2_CE 16 //chip enable
 
@@ -24,6 +25,16 @@
 #define WIFI_CHECK_TIMEOUT 20000
 #define PREVENTIVE_RESET_DELAY 18000000 //Every 5 hours
 
+/* LoRa module pinout definition (using the IO expander) */
+#define LORA_CS_PIN  (PCF8574::P5)
+#define LORA_RST_PIN (PCF8574::P6)
+#define LORA_DI0_PIN (PCF8574::P7)
+
+#define LORA_BAND (868E6)
+
+/* PCF8574 IO expander pinout */
+#define PCF_INT_PIN (D9)
+
 uint8_t payload[32] = {0};
 DataPacket dp;
 WeatherStationDataPacket wsdp;
@@ -48,21 +59,49 @@ int insertIntoDBError(0);
 volatile boolean IRQFlag(false);
 boolean waitingForResetSignal(false), resetNow(false);
 
-IRAM_ATTR void NRFIRQsHandler(void *p)
+void PCFPinMode(uint8_t pin, uint8_t mode)
 {
-  Serial.println("NRF IRQs detected !");
-  *(boolean *)p = true;
+    PCF.pinMode(static_cast<PCF8574::Pin>(pin), static_cast<boolean>(mode));
 }
 
-void setup() {
+void PCFDigitalWrite(uint8_t pin, uint8_t val)
+{
+    PCF.digitalWrite(static_cast<PCF8574::Pin>(pin), static_cast<boolean>(val));
+}
+
+void onLoRaReceive(int payload_size)
+{
+    PCF.digitalWrite(PCF8574::P2, LOW);
+    Serial.printf("LoRa packet size : %d\n", payload_size);
+
+    for(int i = 0; i < payload_size; i++)
+    {
+        Serial.printf("%c", LoRa.read());
+    }
+    Serial.printf("\nPacket RSSI : %d dBm\n", LoRa.packetRssi());
+    PCF.digitalWrite(PCF8574::P2, HIGH);
+}
+
+IRAM_ATTR void PCFIRQHandler(void *p)
+{
+  Serial.println("PCF IRQs detected !");
+  bool pinStates[8];
+  PCF.digitalReadAll(pinStates);
+  *(boolean *)p = true;
+
+  /* If the IRQ pin is the DI0 one, manually call the LoRa IRQ handler */
+  if(pinStates[7] == HIGH)
+  {
+    LoRa.handleDio0Rise();
+  }
+}
+
+void setup() 
+{
   //We do not need to read on the serial bus
   Serial.begin(115200, SERIAL_8N1, SERIAL_TX_ONLY);
   delay(1000);
   Serial.println("\nSetup begin");
-  //We set the RXD0 as a GPIO
-  pinMode(D9, FUNCTION_3);
-  pinMode(D9, INPUT_PULLUP);
-  attachInterruptArg(D9,&(NRFIRQsHandler), (void *)&IRQFlag, FALLING);
   //We set the WiFi part up :
   gotIp = WiFi.onStationModeGotIP(&(gotIpFunc));
   lostConnection = WiFi.onStationModeDisconnected(&(lostConnectionFunc));
@@ -124,6 +163,24 @@ void setup() {
   PCF.pinMode(PCF8574::P2, OUTPUT);
   PCF.pinMode(PCF8574::P3, OUTPUT);
   PCF.pinMode(PCF8574::P4, OUTPUT);
+
+  /* Configuring LoRa module and RF settings */
+  LoRa.setPins(LORA_CS_PIN, LORA_RST_PIN, LORA_DI0_PIN);
+  LoRa.setCustomGPIOFn(&(PCFPinMode), &(PCFDigitalWrite));
+  Serial.printf("LoRa module %s\n", LoRa.begin(LORA_BAND) ? "found" : "not found");
+  Serial.println("######### LoRa regs : #########");
+  LoRa.dumpRegisters(Serial);
+  Serial.println("###############################");
+  LoRa.setSpreadingFactor(10);
+  LoRa.enableCrc();
+  LoRa.onReceive(&(onLoRaReceive));
+  /* Let's start listening to LoRa packets */
+  LoRa.receive();
+
+  //We set the RXD0 as a GPIO
+  pinMode(PCF_INT_PIN, INPUT_PULLUP);
+  attachInterruptArg(PCF_INT_PIN, &(PCFIRQHandler), (void *)&IRQFlag, ONLOW /*FALLING*/);
+
   Serial.println("End setup");
 }