Circuit Documentation

Summary

This document provides a detailed overview of a circuit that integrates an ESP32 microcontroller with an RFM95 LoRa module and an inductor. The ESP32 is programmed to initialize the LoRa module and send a simple message periodically.

Component List

ESP32

• Description: A powerful microcontroller with integrated Wi-Fi and Bluetooth capabilities.
• Pins: EN, VP, VN, D34, D35, D32, D33, D25, D26, D27, D14, D12, D13, GND, VIN, 3V3, D15, D2, D4, RX2, TX2, D5, D18, D19, D21, RX0, TX0, D22, D23, BOOT

RFM95

• Description: A LoRa transceiver module used for long-range communication.
• Pins: DIO2, DIO1, DIO0, 3.3V, DIO4, DIO3, GND, ANT, MISO, MOSI, SCK, NSS, RESET, DIO5

Inductor

• Description: A passive electronic component that stores energy in a magnetic field.
• Pins: pin 0, pin 1
• Properties:
  • Inductance: 1 µH

Wiring Details

ESP32

• D13 is connected to RFM95 DIO0
• 3V3 is connected to RFM95 3.3V
• GND is connected to RFM95 GND
• D19 is connected to RFM95 MISO
• D23 is connected to RFM95 MOSI
• D18 is connected to RFM95 SCK
• D14 is connected to RFM95 NSS
• D27 is connected to RFM95 RESET

RFM95

• DIO0 is connected to ESP32 D13
• 3.3V is connected to ESP32 3V3
• GND is connected to ESP32 GND
• MISO is connected to ESP32 D19
• MOSI is connected to ESP32 D23
• SCK is connected to ESP32 D18
• NSS is connected to ESP32 D14
• RESET is connected to ESP32 D27
• ANT is connected to Inductor pin 1

Inductor

• pin 1 is connected to RFM95 ANT

Code Documentation

/*
 * LoRa Transmitter
 * This Arduino sketch configures an ESP32 to communicate with an RFM95 LoRa
 * module. The ESP32 will initialize the LoRa module and send a simple message.
 */

#include <SPI.h>
#include <LoRa.h>

// Pin definitions
#define LORA_SS 14
#define LORA_RST 27
#define LORA_DIO0 13

void setup() {
  // Initialize serial communication
  Serial.begin(9600);
  while (!Serial);
  Serial.println("LoRa Transmitter");

  // Setup LoRa transceiver module
  LoRa.setPins(LORA_SS, LORA_RST, LORA_DIO0);

  if (!LoRa.begin(915E6)) { // Initialize LoRa at 915 MHz
    Serial.println("Starting LoRa failed!");
    while (1);
  }
  Serial.println("LoRa Initializing OK!");
}

void loop() {
  Serial.println("Sending packet...");
  // Send packet
  LoRa.beginPacket();
  LoRa.print("Hello, world!");
  LoRa.endPacket();

  delay(5000); // Wait for 5 seconds before sending next packet
}

This code initializes the LoRa module connected to the ESP32 and sends a "Hello, world!" message every 5 seconds. The pin definitions in the code match the wiring details provided above.