How to Connect ADXL345 to Raspberry Pi Pico

In this tutorial learn how to connect the ADXL345 to the Raspberry Pi Pico to get real acceleration values.

You can purchase this sensor here:


1-) Step One: Physical Connection

Setup pins as follows for I2C connection, you only need 4 jumper wires

2-) Step Two: Code

Run the following code in MicroPython:

from machine import Pin, I2C
import time
import ustruct
# Constants
ADXL345_ADDRESS = 0x53 # address for accelerometer 
ADXL345_POWER_CTL = 0x2D # address for power control
ADXL345_DATA_FORMAT = 0x31 # configure data format
ADXL345_DATAX0 = 0x32 # where the x-axis data starts
# Initialize I2C
i2c = I2C(0, sda=Pin(0), scl=Pin(1), freq=400000)
# Initialize ADXL345
def init_adxl345():
    i2c.writeto_mem(ADXL345_ADDRESS, ADXL345_POWER_CTL, bytearray([0x08]))  # Set bit 3 to 1 to enable measurement mode
    i2c.writeto_mem(ADXL345_ADDRESS, ADXL345_DATA_FORMAT, bytearray([0x0B]))  # Set data format to full resolution, +/- 16g
# Read acceleration data
def read_accel_data():
    data = i2c.readfrom_mem(ADXL345_ADDRESS, ADXL345_DATAX0, 6)
    x, y, z = ustruct.unpack('<3h', data)
    return x, y, z
# Main loop
while True:
    x, y, z = read_accel_data()
    print(x, y, z)
    print("X: {}, Y: {}, Z: {}".format(x*0.0039, y*0.0039, z*0.0039))
# if you do get OSError: [Errno 5] EIO, try unplug and plug
# if you do set different resolution 0.0039 may not be the constant (check data sheet)

If you set everything up properly you should start seeing values in x, y, and z in units of g (9.81 m/s^2).

Sensor calibration may be needed to produce more accurate values, you can find that on my channel.


Please consider subbing to the channel if this helped you in any way, would help us create more content for you! Let me know if you have any questions. Thanks!

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