seeed xiao nrf52 SENSE Accelerometer LSM6DS3TR-C

[gassechen]

Example that shows the use of the accelerometer and configures the interrupts for double-tap interrupt

# RJS ***  import machine so it can be used as a module
import machine
from machine import Pin
import time

ADDRESS = 0x6A  # I2C address of LSM6DS3
CTRL1_XL = 0x10  # Accelerometer control register
TAP_CFG1 = 0x58
TAP_THS_6D = 0x59
INT_DUR2 = 0x5A
WAKE_UP_THS = 0x5B
MD1_CFG = 0x5E
OUTX_L_XL = 0x28  # Accelerometer X-axis output register


FSR_2G = 16384.0  # FSR for 2G mode
FSR_4G = 8192.0   # FSR for 4G mode
FSR_8G = 4096.0   # FSR for 8G mode
FSR_16G = 2048.0  # FSR for 16G mode



# Initialize I2C bus
i2c = machine.I2C(0, scl=machine.Pin(27), sda=machine.Pin(7))

# RJS *** declare pin for LED
led = Pin(26, Pin.OUT)

time.sleep_ms(50)
interruptCount = 0
prevInterruptCount = 0

def read_accelerometer_data(FSR):
    # Get accelerometer data
    data = i2c.readfrom_mem(ADDRESS, OUTX_L_XL, 6)
    # Convert data to G units
    x = (data[1] << 8 | data[0]) / FSR
    y = (data[3] << 8 | data[2]) / FSR
    z = (data[5] << 8 | data[4]) / FSR
    # Output values
    print('X: {} G, Y: {} G, Z: {} G'.format(x, y, z))


# Configure tap detection
def configure_double_tap_detection():
    i2c.writeto_mem(ADDRESS, CTRL1_XL, bytes([0x60]))
    i2c.writeto_mem(
        ADDRESS, TAP_CFG1, bytes([0x8E])
    )  # enable interrupt(0x80), tap xyz (0x0E)
    i2c.writeto_mem(ADDRESS, TAP_THS_6D, bytes([0x8C]))
    i2c.writeto_mem(ADDRESS, INT_DUR2, bytes([0x7F]))
    i2c.writeto_mem(ADDRESS, WAKE_UP_THS, bytes([0x80]))  # single and double tap
    i2c.writeto_mem(ADDRESS, MD1_CFG, bytes([0x08]))  # double tap to INT1


# Define tap_interrupt function to handle tap events
# RJS *** pin interrupt handler routine needs one argument- the pin
#         your original had a pin argument
def double_tap_interrupt(pin):
    global interruptCount
    interruptCount = interruptCount + 1
    print("Tap detected")
    # RJS *** off and on are functions (see uPy documentation)
    #         and XIAO has inverted logic on board LED (high is off)
    #         again your original had the right usage .
    led.off()  # Turn on the LED... on/off are functions
    # led wiring on XIAO is inverted
    # same as led.value(0)
    time.sleep_ms(50)  # Wait for a short time
    led.on()  # Turn off the LED
    # sane as led.value(1)


machine.enable_irq()
configure_double_tap_detection()

tap_pin = Pin(11, Pin.IN, Pin.PULL_UP)
tap_pin.irq(trigger=Pin.IRQ_RISING, handler=double_tap_interrupt)




while True:
    read_accelerometer_data(FSR_2G)
    
    if interruptCount > prevInterruptCount:
        print("Interrupt received!")

    prevInterruptCount = interruptCount
    print("Interrupt Counter: " + str(prevInterruptCount))
    time.sleep_ms(300)

[gassechen]

To configure single-tap detection use:

# Configure tap detection
def configure_single_tap_detection():
    i2c.writeto_mem(ADDRESS, CTRL1_XL, bytes([0x60]))
    i2c.writeto_mem(ADDRESS, TAP_CFG1, bytes([0x8E])) 
    i2c.writeto_mem(ADDRESS, TAP_THS_6D, bytes([0x09]))
    i2c.writeto_mem(ADDRESS, INT_DUR2, bytes([0x06]))
    i2c.writeto_mem(ADDRESS, WAKE_UP_THS, bytes([0x00]))  # single and double tap
    i2c.writeto_mem(ADDRESS, MD1_CFG, bytes([0x40]))  # double tap to INT1

[Arakistech]

What is the current draw?

[gassechen]

Excuse me not and I understand

[gassechen]

To configure Free Fall :

FREE_FALL = 0x5D  

# Configure Free Fall detection
def configure_single_tap_detection():
    i2c.writeto_mem(ADDRESS, CTRL1_XL, bytes([0x60]))
    i2c.writeto_mem(ADDRESS, TAP_CFG1, bytes([0x81])) 
    i2c.writeto_mem(ADDRESS, FREE_FALL, bytes([0x7F]))
    i2c.writeto_mem(ADDRESS, WAKE_UP_THS, bytes([0x33])) 
    i2c.writeto_mem(ADDRESS, MD1_CFG, bytes([0x10]))  # double tap to INT1

[gassechen]

To configure wake-up detection

WAKE_UP_DUR = 0x5C

# Configure wake-up detection
def configure_wake_up_detection():
    #no duration
    i2c.writeto_mem(ADDRESS, WAKE_UP_DUR, bytes([0x00])) 
    #Set wake-up threshold
    i2c.writeto_mem(ADDRESS, WAKE_UP_THS, bytes([0x02]))
    #Enable interrupts and apply slope filter; latch mode disabled
    i2c.writeto_mem(ADDRESS, TAP_CFG1, bytes([0x80]))
    #Turn on the accelerometer  ODR_XL = 833 Hz, FS_XL = ±2 g
    i2c.writeto_mem(ADDRESS, CTRL1_XL, bytes([0x70]))
    
    time.sleep_ms(4) #Insert (reduced) wait time
    #ODR_XL = 12.5 Hz
    i2c.writeto_mem(ADDRESS, CTRL1_XL, bytes([0x10]))
    
    #Wake-up interrupt driven to INT1 pin
    i2c.writeto_mem(ADDRESS, MD1_CFG, bytes([0x20]))

[ricksorensen]

Here is a resource for XIAO NRF52840 questions/issues - not so much python/micropython though:
https://forum.seeedstudio.com/

[gassechen]

If not much about micropython. I only found one example of using interrupts for arduino core.

[gassechen]

configure to 6D orientation detection:

CTRL8_XL = 0x17

# Configure tap detection
def configure_6D_orientation_detection():
    #Turn on the accelerometer  ODR_XL = 416 Hz, FS_XL = ±2 g
    i2c.writeto_mem(ADDRESS, CTRL1_XL, bytes([0x60]))
    #Enable interrupts and apply slope filter; latch mode disabled
    i2c.writeto_mem(ADDRESS, TAP_CFG1, bytes([0x80]))
    
    i2c.writeto_mem(ADDRESS, TAP_THS_6D, bytes([0x40]))
    # Enable LPF2 filter to 6D functionality
    i2c.writeto_mem(ADDRESS, CTRL8_XL, bytes([0x01])) 
    
    #6D interrupt driven to INT1 pin
    i2c.writeto_mem(ADDRESS, MD1_CFG, bytes([0x04])) 

[gassechen]

Configure to 4d orientation detection

# Configure 4d orientation detection
def configure_4D_orientation_detection():
    #Turn on the accelerometer  ODR_XL = 416 Hz, FS_XL = ±2 g
    i2c.writeto_mem(ADDRESS, CTRL1_XL, bytes([0x60]))
    #Enable interrupts and apply slope filter; latch mode disabled
    i2c.writeto_mem(ADDRESS, TAP_CFG1, bytes([0x80]))
    
    i2c.writeto_mem(ADDRESS, TAP_THS_6D, bytes([0xC0]))
    # Enable LPF2 filter to 6D functionality
    i2c.writeto_mem(ADDRESS, CTRL8_XL, bytes([0x01])) 
    
    #6D interrupt driven to INT1 pin
    i2c.writeto_mem(ADDRESS, MD1_CFG, bytes([0x04]))