Library for interacting through the SPI protocol with an 'Analog Devices ADXL345' accelerometer from an ESP32 MCU, flashed with MicroPython.
Methods are optimised for continuos readings at max frequency (3.2kHz).
The following wirings refers to the tested setup on an ESP32-WROVER:
| ADXL345 Pin name | ESP32 Pin name (number) |
|---|---|
| Vs | 3v3 |
| GND | GND |
| CS | vspi cs (D5) |
| SCL/SCLK | vspi scl (D18) |
| SDO/ALT ADDRESS | vspi miso (D19) |
| SDA/SDI/SDO | vspi mosi (D23) |
""" read one x, y, z """
from ADXL345_spi import ADXL345 as Accelerometer
accelerometer = Accelerometer(cs_pin=5, scl_pin=18, sda_pin=23, sdo_pin=19, spi_freq=5000000)
accelerometer.init_spi()
accelerometer.set_sampling_rate(1.56) # Hz
accelerometer.set_g_range(2) # pm 2g
accelerometer.set_fifo_mode('bypass')
accelerometer.set_power_mode('measure')
buf, T = accelerometer.read_many_xyz(n=1)
accelerometer.set_power_mode('standby')
x, y, z = accelerometer.xyzbytes2g(buf) # g units
accelerometer.deinit_spi() # this is necessary, otherwise if another SPI is initialized it won't work""" read many x, y, z """
from ADXL345_spi import ADXL345 as Accelerometer
accelerometer = Accelerometer() # assumes accelerometer is connected to ESP32 vspi default Pins
accelerometer.init_spi()
accelerometer.set_sampling_rate(3200)
accelerometer.set_g_range(2)
accelerometer.set_fifo_mode('bypass')
accelerometer.set_power_mode('measure')
buf, T = accelerometer.read_many_xyz(n=10)
accelerometer.set_power_mode('standby')
x, y, z = accelerometer.xyzbytes2g(buf)
accelerometer.deinit_spi()""" read continuosly when data is ready """
from ADXL345_spi import ADXL345 as Accelerometer
accelerometer = Accelerometer()
accelerometer.init_spi()
accelerometer.set_sampling_rate(3200)
accelerometer.set_g_range(2)
accelerometer.set_fifo_mode('bypass')
accelerometer.set_power_mode('measure')
buf, T = accelerometer.read_continuos_xyz(acquisition_time=1.5)
accelerometer.set_power_mode('standby')
x, y, z = accelerometer.xyzbytes2g(buf)
accelerometer.deinit_spi()""" read continuosly from fifo """
from ADXL345_spi import ADXL345 as Accelerometer
accelerometer = Accelerometer()
accelerometer.init_spi()
accelerometer.set_sampling_rate(3200)
accelerometer.set_g_range(2)
accelerometer.set_fifo_mode('stream')
accelerometer.set_power_mode('measure')
buf, T = accelerometer.read_continuos_xyz_fromfifo(acquisition_time=1.5)
accelerometer.set_power_mode('standby')
x, y, z = accelerometer.xyzbytes2g(buf)
accelerometer.deinit_spi()