mc3479¶

MC3479 Accelerometer MicroPython Driver

• Author: Jose D. Montoya

class micropython_mc3479.mc3479.MC3479(i2c, address: int = 0x4C)[source]¶

Driver for the MC3479 Sensor connected over I2C.

Parameters:¶

i2c : I2C¶

The I2C bus the MC3479 is connected to.

address : int¶

The I2C device address. Defaults to 0x4C

Raises:¶

RuntimeError – if the sensor is not found

Quickstart: Importing and using the device

Here is an example of using the micropython_mc3479.MC3479 class. First you will need to import the libraries to use the sensor

from machine import Pin, I2C
import micropython_mc3479 as MC3479

Once this is done you can define your machine.I2C object and define your sensor object

i2c = I2C(sda=Pin(8), scl=Pin(9))  # Correct I2C pins for UM FeatherS2
mc3479 = MC3479.MC3479(i2c)

Now you have access to the attributes

accx, accy, accz = mc3479.acceleration

property acceleration : tuple[float, float, float]¶

The device has the ability to read all sampled readings in a continuous sampling fashion. The device always updates the XOUT, YOUT, and ZOUT registers at the chosen output data rate

X, Y, and Z-axis accelerometer measurements are in 16-bit, signed 2’s complement format. Register addresses 0x0D to 0x12 hold the latest sampled data from the X, Y, and Z accelerometers.

property acceleration_output_data_rate : str¶

Define the output data rate in Hz The output data rate is dependent of the power mode setting for the sensor

Mode	Value
MC3479.BANDWIDTH_50	0x08 50 Hz
MC3479.BANDWIDTH_100	0x09 100 Hz
MC3479.BANDWIDTH_125	0xA 125 Hz
MC3479.BANDWIDTH_200	0xB 200 Hz
MC3479.BANDWIDTH_250	0xC 250 Hz
MC3479.BANDWIDTH_500	0xD 500 Hz
MC3479.BANDWIDTH_1000	0xE 1000 Hz
MC3479.BANDWIDTH_2000	0xF 2000 Hz

Example¶

i2c = I2C(sda=Pin(8), scl=Pin(9))  # Correct I2C pins for UM FeatherS2
mc3479 = MC3479.MC3479(i2c)
mc3479.acceleration_output_data_rate = MC3479.BANDWIDTH_500

property acceleration_range : str¶

The range and scale control register sets the resolution, range, and filtering options for the accelerometer. All values are in sign-extended 2’s complement format. Values are reported in registers 0x0D - 0x12 (the hardware formats the output)

Mode	Value
MC3479.ACCEL_RANGE_2G	0b000
MC3479.ACCEL_RANGE_4G	0b001
MC3479.ACCEL_RANGE_8G	0b010
MC3479.ACCEL_RANGE_16G	0b011
MC3479.ACCEL_RANGE_12G	0b100

Example¶

i2c = I2C(sda=Pin(8), scl=Pin(9))  # Correct I2C pins for UM FeatherS2
mc3479 = MC3479.MC3479(i2c)
mc3479.acceleration_range = MC3479.ACCEL_RANGE_12G

property lpf_enabled : str¶

Low Power Filter Enabler

Mode	Value
MC3479.LPF_ENABLE	0b0
MC3479.LPF_DISABLE	0b1

Example¶

i2c = I2C(sda=Pin(8), scl=Pin(9))  # Correct I2C pins for UM FeatherS2
mc3479 = MC3479.MC3479(i2c)
mc3479.lpf_enabled = MC3479.LPF_ENABLE

property lpf_setting : str¶

Selects the Bandwidth for the Low Power Filter. Depends on the selection of the ODR/IDR

Mode	Value
MC3479.BANDWIDTH_1	0b001 Fc = IDR / 4.255
MC3479.BANDWIDTH_2	0b010 Fc = IDR / 6
MC3479.BANDWIDTH_3	0b011 Fc = IDR / 12
MC3479.BANDWIDTH_5	0b101 Fc = IDR / 16

Example¶

i2c = I2C(sda=Pin(8), scl=Pin(9))  # Correct I2C pins for UM FeatherS2
mc3479 = MC3479.MC3479(i2c)

mc3479.lpf_setting = MC3479.BANDWIDTH_5

property sensor_mode : str¶

Standby¶

• Lowest power consumption

• Internal clocking is halted

• No motion detection, sampling, or calibration

• The I2C/SPI bus can read and write to registers (resolution, range, thresholds and other settings can be changed)

• Reset not allowed

• Default state after a power-up

Normal¶

• Highest power consumption

• Internal clocking is enabled

• Continuous motion detection and sampling; automatic calibration is available

• The I2C/SPI bus can only write to the mode register and read all other registers

• Reset allowed

Mode	Value
MC3479.STANDBY	0
MC3479.NORMAL	1