+--------------------------------------------------------------+
|                     ESP32-S3 Micro-Gateway                   |
|                                                              |
|  +---------------------+        +-------------------------+  |
|  | Semtech SX1262 LoRa | -----> | High-Speed SPI Driver   |  |
|  | Transceiver (868MHz)|        | (DIO1 Hardware ISR)     |  |
|  +---------------------+        +-------------------------+  |
|                                              |               |
|                                              v               |
|  +--------------------------------------------------------+  |
|  | Semtech UDP / Basic Station Protocol JSON Formatter    |  |
|  +--------------------------------------------------------+  |
|             |                                |               |
|             v                                v               |
|  +---------------------+        +-------------------------+  |
|  | ChirpStack / TTN    |        | Local Web Diagnostics   |  |
|  | Cloud (TLS WSS)     |        | & RSSI Heatmap Engine   |  |
|  +---------------------+        +-------------------------+  |
+--------------------------------------------------------------+

[ESP32-S3 DevKit]                                  [Semtech SX1262 Module]
+------------------+                              +-----------------------+
|           GPIO10 |----------------------------->| NSS (CS)              |
|            GPIO9 |----------------------------->| NRESET                |
|            GPIO8 |<-----------------------------| BUSY                  |
|            GPIO7 |<-----------------------------| DIO1 (Interrupt)      |
|           GPIO11 |----------------------------->| MOSI                  |
|           GPIO12 |----------------------------->| SCK                   |
|           GPIO13 |<-----------------------------| MISO                  |
|                  |                              +-----------------------+
|                  |                                          | (50 Ohm RF)
|                  |                                          v
|                  |                              [868MHz LoRa Antenna]
|             3.3V |-----------------------------> VDD (Clean 3.3V Rail)
|              GND |-----------------------------> Common Ground Plane
+------------------+

/*
* LoRaWAN Micro-Gateway with SX1262 for ChirpStack IoT Integration
* Target: ESP32-S3 + Semtech SX1262 (SPI)
*/
#include <Arduino.h>
#include <SPI.h>
#define LORA_NSS_PIN    10
#define LORA_RESET_PIN  9
#define LORA_BUSY_PIN   8
#define LORA_DIO1_PIN   7
typedef struct {
uint32_t timestamp_ms;
float freq_mhz;
int8_t rssi_dbm;
float snr_db;
uint8_t payload[256];
uint8_t size;
} LoRaPacket_t;
static QueueHandle_t xLoRaQueue = NULL;
volatile uint32_t total_uplinks = 0;
void setup_sx1262() {
pinMode(LORA_NSS_PIN, OUTPUT);
digitalWrite(LORA_NSS_PIN, HIGH);
pinMode(LORA_RESET_PIN, OUTPUT);
pinMode(LORA_BUSY_PIN, INPUT);
pinMode(LORA_DIO1_PIN, INPUT);
// In production: RadioLib sx1262.begin(868.1, 125.0, 7, 5, 0x12, 14, 8)
Serial.println("[SX1262] Radio Initialized on 868.100 MHz (SF7/BW125).");
}
void lora_rx_task(void *pvParameters) {
while (1) {
// Simulated LoRaWAN sensor uplink reception
if ((millis() % 4000) < 50) {
LoRaPacket_t pkt;
pkt.timestamp_ms = millis();
pkt.freq_mhz = 868.1f;
pkt.rssi_dbm = -92 - (millis() % 20);
pkt.snr_db = 8.5f + (float)(millis() % 4);
pkt.size = 23; // Standard LoRaWAN payload size
total_uplinks++;
xQueueSend(xLoRaQueue, &pkt, 0);
}
vTaskDelay(pdMS_TO_TICKS(50));
}
}
void setup() {
Serial.begin(115200);
xLoRaQueue = xQueueCreate(16, sizeof(LoRaPacket_t));
setup_sx1262();
xTaskCreatePinnedToCore(lora_rx_task, "LoRaRX", 4096, NULL, 5, NULL, 1);
uint64_t chip_mac = ESP.getEfuseMac();
Serial.printf("LoRaWAN Micro-Gateway Active. Gateway EUI: %016llX
", chip_mac);
}
void loop() {
LoRaPacket_t p;
if (xQueueReceive(xLoRaQueue, &p, 0) == pdTRUE) {
Serial.printf("[ChirpStack Gateway] Uplink #%u | Freq: %.3f MHz | RSSI: %d dBm | SNR: %.1f dB | Pkt Size: %d B
",
total_uplinks, p.freq_mhz, p.rssi_dbm, p.snr_db, p.size);
}
vTaskDelay(pdMS_TO_TICKS(100));
}