Initial commit: Add basic QMC5883P library

- Add core library files (Adafruit_QMC5883P.h/.cpp)
- Add basic example sketch with chip detection
- Add standard Adafruit project files (.clang-format, README.md, GitHub workflows)
- Library successfully tests I2C communication and chip ID verification

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

.clang-format

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+Language: Cpp
+BasedOnStyle: Google
+IndentWidth: 2
+ColumnLimit: 80
+AllowShortFunctionsOnASingleLine: Empty
+AllowShortIfStatementsOnASingleLine: false
+AllowShortLoopsOnASingleLine: false
+BinPackArguments: true
+BinPackParameters: true
+BreakBeforeBraces: Attach
+DerivePointerAlignment: false
+PointerAlignment: Left
+SpacesBeforeTrailingComments: 1

.github/workflows/githubci.yml

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+name: Arduino Library CI
+
+on: [pull_request, push, repository_dispatch]
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    
+    steps:
+    - uses: actions/setup-python@v1
+      with:
+        python-version: '3.x'
+    - uses: actions/checkout@v2
+    - uses: actions/checkout@v2
+      with:
+         repository: adafruit/ci-arduino
+         path: ci
+
+    - name: pre-install
+      run: bash ci/actions_install.sh
+
+    - name: clang
+      run: python3 ci/run-clang-format.py -e "ci/*" -e "bin/*" -r . 
+
+    - name: test platforms
+      run: python3 ci/build_platform.py main_platforms
+
+    - name: doxygen
+      env:
+        GH_REPO_TOKEN: ${{ secrets.GH_REPO_TOKEN }}
+        PRETTYNAME : "Adafruit QMC5883P Arduino Library"
+      run: bash ci/doxy_gen_and_deploy.sh

.gitignore

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+# Datasheets
+*.pdf
+*.txt
+
+# OS generated files
+.DS_Store
+.DS_Store?
+._*
+.Spotlight-V100
+.Trashes
+ehthumbs.db
+Thumbs.db
+
+# IDE files
+.vscode/
+.idea/
+*.swp
+*.swo
+*~
+
+# Build artifacts
+build/
+bin/
+*.o
+*.a

Adafruit_QMC5883P.cpp

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+/*!
+ * @file Adafruit_QMC5883P.cpp
+ *
+ * @mainpage Adafruit QMC5883P 3-axis magnetometer library
+ *
+ * @section intro_sec Introduction
+ *
+ * This is a library for the QMC5883P 3-axis magnetometer
+ *
+ * These sensors use I2C to communicate, 2 pins (SCL+SDA) are required
+ * to interface with the breakout.
+ *
+ * Adafruit invests time and resources providing this open source code,
+ * please support Adafruit and open-source hardware by purchasing
+ * products from Adafruit!
+ *
+ * @section author Author
+ *
+ * Written by ladyada for Adafruit Industries.
+ *
+ * @section license License
+ *
+ * MIT license, all text here must be included in any redistribution.
+ *
+ */
+
+#include "Adafruit_QMC5883P.h"
+
+/*!
+ *  @brief  Instantiates a new QMC5883P class
+ */
+Adafruit_QMC5883P::Adafruit_QMC5883P(void) { i2c_dev = NULL; }
+
+/*!
+ *  @brief  Cleans up the QMC5883P
+ */
+Adafruit_QMC5883P::~Adafruit_QMC5883P(void) {
+  if (i2c_dev) {
+    delete i2c_dev;
+  }
+}
+
+/*!
+ *  @brief  Sets up the hardware and initializes I2C
+ *  @param  i2c_addr
+ *          The I2C address to be used.
+ *  @param  wire
+ *          The Wire object to be used for I2C connections.
+ *  @return True if initialization was successful, otherwise false.
+ */
+bool Adafruit_QMC5883P::begin(uint8_t i2c_addr, TwoWire *wire) {
+  if (i2c_dev) {
+    delete i2c_dev;
+  }
+
+  i2c_dev = new Adafruit_I2CDevice(i2c_addr, wire);
+
+  if (!i2c_dev->begin()) {
+    return false;
+  }
+
+  // Check chip ID
+  Adafruit_BusIO_Register chip_id_reg = Adafruit_BusIO_Register(i2c_dev, QMC5883P_REG_CHIPID);
+  uint8_t chip_id = chip_id_reg.read();
+  if (chip_id != 0x80) {
+    return false;
+  }
+
+  return true;
+}

Adafruit_QMC5883P.h

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+/*!
+ * @file Adafruit_QMC5883P.h
+ *
+ * This is a library for the QMC5883P 3-axis magnetometer
+ *
+ * These sensors use I2C to communicate, 2 pins (SCL+SDA) are required
+ * to interface with the breakout.
+ *
+ * Adafruit invests time and resources providing this open source code,
+ * please support Adafruit and open-source hardware by purchasing
+ * products from Adafruit!
+ *
+ * Written by ladyada for Adafruit Industries.
+ *
+ * MIT license, all text here must be included in any redistribution.
+ *
+ */
+
+#ifndef _ADAFRUIT_QMC5883P_H_
+#define _ADAFRUIT_QMC5883P_H_
+
+#include "Arduino.h"
+#include <Adafruit_BusIO_Register.h>
+#include <Adafruit_I2CDevice.h>
+
+/*=========================================================================
+    I2C ADDRESS/BITS
+    -----------------------------------------------------------------------*/
+#define QMC5883P_DEFAULT_ADDR 0x2C ///< Default I2C address
+/*=========================================================================*/
+
+/*=========================================================================
+    REGISTERS
+    -----------------------------------------------------------------------*/
+#define QMC5883P_REG_CHIPID 0x00     ///< Chip ID register
+#define QMC5883P_REG_XOUT_LSB 0x01   ///< X-axis output LSB register
+#define QMC5883P_REG_XOUT_MSB 0x02   ///< X-axis output MSB register
+#define QMC5883P_REG_YOUT_LSB 0x03   ///< Y-axis output LSB register
+#define QMC5883P_REG_YOUT_MSB 0x04   ///< Y-axis output MSB register
+#define QMC5883P_REG_ZOUT_LSB 0x05   ///< Z-axis output LSB register
+#define QMC5883P_REG_ZOUT_MSB 0x06   ///< Z-axis output MSB register
+#define QMC5883P_REG_STATUS 0x09     ///< Status register
+#define QMC5883P_REG_CONTROL1 0x0A   ///< Control register 1
+#define QMC5883P_REG_CONTROL2 0x0B   ///< Control register 2
+/*=========================================================================*/
+
+/*!
+ * @brief Class for hardware interfacing with the QMC5883P 3-axis magnetometer
+ */
+class Adafruit_QMC5883P {
+public:
+  Adafruit_QMC5883P(void);
+  ~Adafruit_QMC5883P(void);
+
+  bool begin(uint8_t i2c_addr = QMC5883P_DEFAULT_ADDR, TwoWire *wire = &Wire);
+
+private:
+  Adafruit_I2CDevice *i2c_dev; ///< Pointer to I2C bus interface
+};
+
+#endif

README.md

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+# Adafruit QMC5883P Library [![Build Status](https://github.com/adafruit/Adafruit_QMC5883P/workflows/Arduino%20Library%20CI/badge.svg)](https://github.com/adafruit/Adafruit_QMC5883P/actions)
+
+<a href="https://www.adafruit.com/products/"><img src="assets/board.jpg?raw=true" width="500px"><br/></a>
+
+This is a library for the QMC5883P 3-axis magnetometer
+
+## Features
+
+- 3-axis magnetic field sensing
+- 16-bit resolution
+- I2C interface
+- Multiple full-scale ranges (±2G, ±8G, ±12G, ±30G)
+- Built-in self-test capability
+- Temperature compensation
+
+## Installation
+
+To install, use the Arduino Library Manager and search for "Adafruit QMC5883P" and install the library.
+
+## Dependencies
+
+This library depends on the [Adafruit BusIO library](https://github.com/adafruit/Adafruit_BusIO)
+
+## Hardware
+
+The QMC5883P is a 3-axis magnetometer with I2C interface. It requires a 3.3V or 5V power supply.
+
+## Contributing
+
+Contributions are welcome! Please read our [Code of Conduct](https://github.com/adafruit/Adafruit_QMC5883P/blob/master/CODE_OF_CONDUCT.md) before contributing to help this project stay welcoming.
+
+## License
+
+MIT license, all text above must be included in any redistribution. See license.txt for more information.

examples/test_QMC5883P/test_QMC5883P.ino

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+/*
+ * QMC5883P Test Sketch
+ * 
+ * Basic test for the QMC5883P 3-axis magnetometer
+ */
+
+#include <Adafruit_QMC5883P.h>
+
+Adafruit_QMC5883P qmc;
+
+void setup() {
+  Serial.begin(115200);
+  while (!Serial) delay(10);
+  
+  Serial.println("QMC5883P Test");
+  
+  if (!qmc.begin()) {
+    Serial.println("Failed to find QMC5883P chip");
+    while (1) delay(10);
+  }
+  
+  Serial.println("QMC5883P Found!");
+}
+
+void loop() {
+  delay(1000);
+}

package-lock.json

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+{
+  "name": "Adafruit_QMC5883P",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {}
+}

package.json

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+{}