From 7e87fa4a3a96543e1ebceb81888c8cc6745c3975 Mon Sep 17 00:00:00 2001 From: Thomas Farstrike Date: Wed, 23 Apr 2025 16:28:23 +0200 Subject: [PATCH] Add QMI8685 accelerometer driver --- install.sh | 1 + lib/qmi8685.py | 144 +++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 145 insertions(+) create mode 100644 lib/qmi8685.py diff --git a/install.sh b/install.sh index 58676e40..80b9701a 100755 --- a/install.sh +++ b/install.sh @@ -4,6 +4,7 @@ pkill -f "python.*mpremote" ~/sources/lvgl_micropython/lib/micropython/tools/mpremote/mpremote.py fs cp main.py :/main.py ~/sources/lvgl_micropython/lib/micropython/tools/mpremote/mpremote.py fs cp -r apps :/ +~/sources/lvgl_micropython/lib/micropython/tools/mpremote/mpremote.py fs cp -r lib :/ ~/sources/lvgl_micropython/lib/micropython/tools/mpremote/mpremote.py fs cp -r resources :/ ~/sources/lvgl_micropython/lib/micropython/tools/mpremote/mpremote.py reset diff --git a/lib/qmi8685.py b/lib/qmi8685.py new file mode 100644 index 00000000..db0c144b --- /dev/null +++ b/lib/qmi8685.py @@ -0,0 +1,144 @@ +# A simple driver for the QMI8658 IMU. +# From https://github.com/echo-lalia/qmi8658-micropython +# But removed the multi line comments that were causing problems. + +import struct +import time + +from machine import I2C + + +# Sensor constants +_QMI8685_PARTID = const(0x05) +_REG_PARTID = const(0x00) +_REG_REVISION = const(0x01) + +_REG_CTRL1 = const(0x02) # Serial interface and sensor enable +_REG_CTRL2 = const(0x03) # Accelerometer settings +_REG_CTRL3 = const(0x04) # Gyroscope settings +_REG_CTRL4 = const(0x05) # Magnetomer settings (support not implemented in this driver yet) +_REG_CTRL5 = const(0x06) # Sensor data processing settings +_REG_CTRL6 = const(0x07) # Attitude Engine ODR and Motion on Demand +_REG_CTRL7 = const(0x08) # Enable Sensors and Configure Data Reads + +_REG_TEMP = const(0x33) # Temperature sensor. + +_REG_AX_L = const(0x35) # Read accelerometer +_REG_AX_H = const(0x36) +_REG_AY_L = const(0x37) +_REG_AY_H = const(0x38) +_REG_AZ_L = const(0x39) +_REG_AZ_H = const(0x3A) + +_REG_GX_L = const(0x3B) # read gyro +_REG_GX_H = const(0x3C) +_REG_GY_L = const(0x3D) +_REG_GY_H = const(0x3E) +_REG_GZ_L = const(0x3F) +_REG_GZ_H = const(0x40) + +_QMI8658_I2CADDR_DEFAULT = const(0X6B) + + +_ACCELSCALE_RANGE_2G = const(0b00) +_ACCELSCALE_RANGE_4G = const(0b01) +_ACCELSCALE_RANGE_8G = const(0b10) +_ACCELSCALE_RANGE_16G = const(0b11) + +_GYROSCALE_RANGE_16DPS = const(0b000) +_GYROSCALE_RANGE_32DPS = const(0b001) +_GYROSCALE_RANGE_64DPS = const(0b010) +_GYROSCALE_RANGE_128DPS = const(0b011) +_GYROSCALE_RANGE_256DPS = const(0b100) +_GYROSCALE_RANGE_512DPS = const(0b101) +_GYROSCALE_RANGE_1024DPS = const(0b110) +_GYROSCALE_RANGE_2048DPS = const(0b111) + +_ODR_8000HZ = const(0b0000) +_ODR_4000HZ = const(0b0001) +_ODR_2000HZ = const(0b0010) +_ODR_1000HZ = const(0b0011) +_ODR_500HZ = const(0b0100) +_ODR_250HZ = const(0b0101) +_ODR_125HZ = const(0b0110) +_ODR_62_5HZ = const(0b0111) + + +class QMI8658: + + def __init__( + self, + i2c_bus: I2C, + address: int = _QMI8658_I2CADDR_DEFAULT, + accel_scale: int = _ACCELSCALE_RANGE_8G, + gyro_scale: int = _GYROSCALE_RANGE_256DPS): + """Read from a sensor on the given I2C bus, at the given address.""" + self.i2c = i2c_bus + self.address = address + + # Verify sensor part ID + if self._read_u8(_REG_PARTID) != _QMI8685_PARTID: + raise AttributeError("Cannot find a QMI8658") + + # Setup initial configuration + self._configure_sensor(accel_scale, gyro_scale) + + # Configure scales/divisors for the driver + self.acc_scale_divisor = { + _ACCELSCALE_RANGE_2G: 1 << 14, + _ACCELSCALE_RANGE_4G: 1 << 13, + _ACCELSCALE_RANGE_8G: 1 << 12, + _ACCELSCALE_RANGE_16G: 1 << 11, + }[accel_scale] + + self.gyro_scale_divisor = { + _GYROSCALE_RANGE_16DPS: 2048, + _GYROSCALE_RANGE_32DPS: 1024, + _GYROSCALE_RANGE_64DPS: 512, + _GYROSCALE_RANGE_128DPS: 256, + _GYROSCALE_RANGE_256DPS: 128, + _GYROSCALE_RANGE_512DPS: 64, + _GYROSCALE_RANGE_1024DPS: 32, + _GYROSCALE_RANGE_2048DPS: 16, + }[gyro_scale] + + + def _configure_sensor(self, accel_scale: int, gyro_scale: int): + # Initialize accelerometer and gyroscope settings + self._write_u8(_REG_CTRL1, 0x60) # Set SPI auto increment and big endian (Ctrl 1) + self._write_u8(_REG_CTRL2, (accel_scale << 4) | _ODR_1000HZ) # Accel Config + self._write_u8(_REG_CTRL3, (gyro_scale << 4) | _ODR_1000HZ) # Gyro Config + self._write_u8(_REG_CTRL5, 0x01) # Low-pass filter enable + self._write_u8(_REG_CTRL7, 0x03) # Enable accel and gyro + time.sleep_ms(100) + + + # Helper functions for register operations + def _read_u8(self, reg:int) -> int: + return self.i2c.readfrom_mem(self.address, reg, 1)[0] + + def _read_xyz(self, reg:int) -> tuple[int, int, int]: + data = self.i2c.readfrom_mem(self.address, reg, 6) + return struct.unpack(' float: + """Get the device temperature.""" + temp_raw = self._read_u8(_REG_TEMP) + return temp_raw / 256 + + @property + def acceleration(self) -> tuple[float, float, float]: + """Get current acceleration reading.""" + raw_accel = self._read_xyz(_REG_AX_L) + return tuple(val / self.acc_scale_divisor for val in raw_accel) + + @property + def gyro(self) -> tuple[float, float, float]: + """Get current gyroscope reading.""" + raw_gyro = self._read_xyz(_REG_GX_L) + return tuple(val / self.gyro_scale_divisor for val in raw_gyro)