unit_mpu6xxx.hpp

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/*
 * SPDX-FileCopyrightText: 2026 M5Stack Technology CO LTD
 *
 * SPDX-License-Identifier: MIT
 */
#ifndef M5_UNIT_IMU_UNIT_UNIT_MPU6XXX_HPP
#define M5_UNIT_IMU_UNIT_UNIT_MPU6XXX_HPP
 
#include <M5UnitComponent.hpp>
#include <m5_utility/container/circular_buffer.hpp>
#include <memory>
#include "unit_mpu6886_data.hpp"
#include "../imu/imu_data_source.hpp"
 
namespace m5 {
namespace unit {
 
class UnitMPU6xxx : public Component,
                    public PeriodicMeasurementAdapter<UnitMPU6xxx, mpu6886::Data>,
                    public m5::imu::IMUDataSource {
    M5_UNIT_COMPONENT_HPP_BUILDER(UnitMPU6xxx, 0x68);
 
public:
    struct config_t {
        bool start_periodic{true};
        mpu6886::AccelRange accel_range{mpu6886::AccelRange::G8};
        mpu6886::GyroRange gyro_range{mpu6886::GyroRange::DPS2000};
        mpu6886::Dlpf dlpf{mpu6886::Dlpf::BW176};
        uint8_t sample_rate_div{3};
    };
 
    virtual ~UnitMPU6xxx()
    {
    }
 
    virtual bool begin() override;
    virtual void update(const bool force = false) override;
 
    config_t config() const
    {
        return _cfg;
    }
    void config(const config_t& cfg)
    {
        _cfg = cfg;
    }
 
    bool writeAccelRange(const mpu6886::AccelRange range);
    bool writeGyroRange(const mpu6886::GyroRange range);
    bool readAccelRange(mpu6886::AccelRange& range);
    bool readGyroRange(mpu6886::GyroRange& range);
 
 
    bool writeSampleRateDiv(const uint8_t div);
    bool readSampleRateDiv(uint8_t& div);
    bool writeDlpf(const mpu6886::Dlpf dlpf);
    bool readDlpf(mpu6886::Dlpf& dlpf);
 
    bool softReset();
 
 
    bool startPeriodicMeasurement(const mpu6886::AccelRange accel_range, const mpu6886::GyroRange gyro_range,
                                  const mpu6886::Dlpf dlpf, const uint8_t sample_rate_div);
    bool startPeriodicMeasurement();
    bool stopPeriodicMeasurement();
 
 
    bool sleep() override;
    bool wakeup() override;
 
    virtual m5::imu::Capability imuSpec() const override
    {
        return m5::imu::Capability::Accel | m5::imu::Capability::Gyro | m5::imu::Capability::Temp;
    }
    virtual m5::imu::Capability readImuRaw(m5::imu::imu_raw_data_t& out) override;
    virtual void imuConvertParam(m5::imu::imu_convert_param_t& out) const override;
 
protected:
    explicit UnitMPU6xxx(const uint8_t addr = DEFAULT_ADDRESS);
 
    virtual bool accepts_whoami(const uint8_t id) const = 0;
    virtual float temperature_res() const = 0;
    virtual float temperature_offset() const = 0;
 
    virtual bool start_periodic_measurement(const mpu6886::AccelRange accel_range, const mpu6886::GyroRange gyro_range,
                                            const mpu6886::Dlpf dlpf, const uint8_t sample_rate_div);
    bool start_periodic_measurement();
    bool stop_periodic_measurement();
    bool read_measurement(mpu6886::Data& d);
    bool write_register8_verified(const uint8_t reg, const uint8_t val);
 
    M5_UNIT_COMPONENT_PERIODIC_MEASUREMENT_ADAPTER_HPP_BUILDER(UnitMPU6xxx, mpu6886::Data);
 
private:
    // Settings for begin(); never written to after that. What is currently on the device lives in
    // the live-state members below, so config() keeps meaning "what was configured"
    config_t _cfg{};
    // Mirrors of the registers this driver can change at runtime. imuConvertParam() needs the range
    // actually in effect (a stale factor would silently misreport every sample), and the no-argument
    // startPeriodicMeasurement() resumes from these rather than reverting to _cfg
    mpu6886::AccelRange _accel_range{};
    mpu6886::GyroRange _gyro_range{};
    mpu6886::Dlpf _dlpf{};
    uint8_t _sample_rate_div{};
    uint32_t _pushed{}, _consumed{};  // readImuRaw pop counters (do not disturb latest()/oldest())
    std::unique_ptr<m5::container::CircularBuffer<mpu6886::Data>> _data{};
};
 
namespace mpu6886 {
constexpr uint32_t DEFAULT_STORED_SIZE{8};
 
namespace command {
// Register addresses (I2C addr 0x68/0x69 by AD0 pin)
constexpr uint8_t REG_GYRO_OFFS_USR{0x13};  // 6 bytes
constexpr uint8_t REG_SMPLRT_DIV{0x19};
constexpr uint8_t REG_CONFIG{0x1A};
constexpr uint8_t REG_GYRO_CONFIG{0x1B};
constexpr uint8_t REG_ACCEL_CONFIG{0x1C};
constexpr uint8_t REG_ACCEL_CONFIG2{0x1D};
constexpr uint8_t REG_FIFO_EN{0x23};
constexpr uint8_t REG_INT_PIN_CFG{0x37};
constexpr uint8_t REG_INT_ENABLE{0x38};
constexpr uint8_t REG_INT_STATUS{0x3A};    // bit0 = DATA_RDY (read clear)
constexpr uint8_t REG_ACCEL_XOUT_H{0x3B};  // 14 bytes: accel6 + temp2 + gyro6 (big-endian)
constexpr uint8_t REG_USER_CTRL{0x6A};
constexpr uint8_t REG_PWR_MGMT_1{0x6B};  // bit7 RESET / bit6 SLEEP / CLKSEL[2:0]
constexpr uint8_t REG_PWR_MGMT_2{0x6C};
constexpr uint8_t REG_WHO_AM_I{0x75};
}  // namespace command
}  // namespace mpu6886
 
}  // namespace unit
}  // namespace m5
#endif