📡 LoRa SX1278 Driver for Nuvoton MS51 (8051 MCU)

A lightweight C library for interfacing SX1278 LoRa modules (e.g. Ai-Thinker LoRa-02) with Nuvoton MS51 microcontrollers. This library provides low-level SPI control, initialization, transmission, and reception functions for LoRa communication in the 433 MHz band.

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📋 Table of Contents

• Features
• Supported Hardware
• Pin Connections
• Getting Started
• Usage
  • Initialization
  • Check LoRa Chip
  • Send LoRa Packet
  • Receive LoRa Packet
• Functions Reference
• Dependencies
• Configuration
• License
• Author

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🚀 Features

• Minimal and efficient C driver
• Compatible with 433 MHz LoRa modules (SX1278)
• Works with Nuvoton MS51 (8051)
• Basic LoRa modes: Sleep, Standby, TX, RX
• No external libraries required
• Easily extensible for other MCU families

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🔌 Supported Hardware

• ✅ Microcontroller: Nuvoton MS51 Series (8051 Core)
• ✅ LoRa Module: SX1278-based (e.g. AiThinker LoRa-02)
• ✅ Interface: SPI + GPIO (DIO0, RESET)

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🧩 Pin Connections

SX1278 Pin	Description	MS51 Pin
NSS	SPI Chip Select	P15
DIO0	IRQ (TxDone/RxDone)	P12
RESET	Hardware Reset	P13
MOSI	SPI MOSI	SPI Line
MISO	SPI MISO	SPI Line
SCK	SPI Clock	SPI Line
VCC / GND	Power (3.3V)	MCU Supply

⚠️ Important: Add a 100 µF capacitor close to the LoRa module’s VCC-GND pins to ensure stable power during transmission.

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🛠️ Getting Started

1. Connect your LoRa module to the MS51 as described.
2. Make sure your SPI and delay functions (Spi_Write_Byte, Spi_Read_Byte, Timer0_Delay) are working.
3. Include the library in your project and call LoRa_Init().

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📦 Usage

🔧 Initialization

Initializes the SPI interface and configures the LoRa module to 433 MHz, max power, and standby mode.

LoRa_Init();

Check LoRa Chip

This function reads the version register (0x42). A correct SX1278 will return 0x12. This helps confirm that communication with the module is functional.

if (LoRa_Check()) {
    // SX1278 is detected and working
} else {
    // LoRa module not found or not responding
}

Send LoRa Packet

char msg[] = "Hello, LoRa!";
LoRa_Send(msg, strlen(msg));

• This function:

  • Writes the message to FIFO (0x00)
  • Sets LoRa to transmit mode (0x83)
  • Waits for DIO0 to go HIGH (TxDone)
  • Clears interrupt flags
  • Use this to send any binary or ASCII data over LoRa.

Receive LoRa Packet

Receives a LoRa packet and reads it into a buffer.

char buffer[64];
unsigned char len = LoRa_Receive(buffer, sizeof(buffer));
buffer[len] = '\0';
printf("Received: %s\n", buffer);

🧠 Built with ❤️ by DiveshRDH

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