Checksum Library for Arduino

A lightweight 8-bit checksum library for Arduino, ESP8266, ESP32 and other AVR/ARM platforms. Provides efficient data integrity verification through simple byte summation.

Features

• 8-bit checksum calculation with overflow
• Incremental calculation mode
• Batch calculation mode
• Initial value: 0xFF (configurable in code)
• Support for both single bytes and byte arrays
• Static methods for one-time calculations
• Memory efficient (minimal footprint)
• No external dependencies

Installation

Using Arduino IDE

1. Download the library as ZIP
2. In Arduino IDE: Sketch → Include Library → Add .ZIP Library...
3. Select the downloaded ZIP file

Using PlatformIO

Add to your platformio.ini:

[env:your_board] platform = espressif32 ; or your platform framework = arduino lib_deps = https://github.com/Developer-RU/ArduinoCRC.git

Usage

#include <Checksum.h>

void setup() {
    Serial.begin(115200);
    
    // Example 1: Incremental calculation
    utils::Checksum checksum;
    checksum.start();
    checksum.add(0x01);
    checksum.add(0x02);
    checksum.add(0x03);
    uint8_t result = checksum.get(); // 0xFF + 0x01 + 0x02 + 0x03 = 0x05
    
    Serial.print("Incremental checksum: 0x");
    Serial.println(result, HEX);
    
    // Example 2: Batch calculation
    uint8_t data[] = {0x01, 0x02, 0x03, 0x04, 0x05};
    uint8_t batchResult = utils::Checksum::calculate(data, sizeof(data));
    
    Serial.print("Batch checksum: 0x");
    Serial.println(batchResult, HEX);
    
    // Example 3: Verification
    uint8_t expected = 0x09;
    bool isValid = utils::Checksum::verify(data, sizeof(data), expected);
    
    Serial.print("Verification: ");
    Serial.println(isValid ? "PASS" : "FAIL");
}

void loop() {
    // Empty
}

API Reference

Class: utils::Checksum

Method	Description
void start()	Resets the checksum to its initial value (0xFF).
void add(uint8_t byte)	Adds a single byte to the checksum.
void add(const uint8_t* data, uint16_t dataLen)	Adds a byte array to the checksum.
uint8_t get() const	Returns the current checksum value.

Static Methods

Method	Description
static uint8_t calculate(const uint8_t* data, uint16_t dataLen)	Calculates the checksum for a byte array in one call.
static bool verify(const uint8_t* data, uint16_t dataLen, uint8_t expected)	Verifies if the calculated checksum for a byte array matches an expected value.

Limitations

8-bit checksum provides basic error detection only

Not cryptographically secure

Susceptible to certain error patterns

Maximum overflow: 255 bytes without loss of precision

Examples

The library includes the following examples (File → Examples → ArduinoCRC):

BasicUsage - Simple checksum calculation and verification

Incremental - Demonstrates incremental checksum building

DataVerification - Complete data integrity check example

SerialMonitor - Interactive checksum calculator via Serial

Platform Compatibility

✅ Arduino Uno/Nano/Mega (AVR) ✅ ESP8266 ✅ ESP32 ✅ Arduino Due (SAM) ✅ Teensy 3.x/4.x ✅ Raspberry Pi Pico (RP2040)

Library Structure

ArduinoCRC/ ├── examples/ # Example sketches ├── src/ │ ├── Checksum.cpp # Implementation │ └── Checksum.h # Header file ├── library.properties # Library metadata ├── keywords.txt # Arduino IDE syntax highlighting ├── LICENSE.md # MIT License └── README.md # This file

Contributing

Contributions are welcome! Please:

Fork the repository

Create a feature branch

Make your changes

Submit a pull request

Report issues at: https://github.com/Developer-RU/ArduinoCRC/issues

Changelog

v1.0.0

Initial release

Links

Repository: https://github.com/Developer-RU/ArduinoCRC

Issues: https://github.com/Developer-RU/ArduinoCRC/issues

Releases: https://github.com/Developer-RU/ArduinoCRC/releases