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Update to use int1 for tap detection #19

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Merged
merged 3 commits into from
Dec 30, 2017
Merged

Update to use int1 for tap detection #19

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9fdbdb1
Update to use int1 for tap detection
kattni Dec 29, 2017
d8e170b
Updates tapped with int pin example
kattni Dec 29, 2017
cadf400
Updates including latching interrupt
kattni Dec 30, 2017
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80 changes: 55 additions & 25 deletions adafruit_lis3dh.py
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Original file line number Diff line number Diff line change
Expand Up @@ -16,6 +16,7 @@

import time
import math
import digitalio
try:
import struct
except ImportError:
Expand All @@ -36,6 +37,7 @@
REG_CTRL4 = const(0x23)
REG_CTRL5 = const(0x24)
REG_OUT_X_L = const(0x28)
REG_INT1SRC = const(0x31)
REG_CLICKCFG = const(0x38)
REG_CLICKSRC = const(0x39)
REG_CLICKTHS = const(0x3A)
Expand All @@ -48,6 +50,7 @@
RANGE_8_G = const(0b10) # +/- 8g
RANGE_4_G = const(0b01) # +/- 4g
RANGE_2_G = const(0b00) # +/- 2g (default value)
DATARATE_1344_HZ = const(0b1001) # 1.344 KHz
DATARATE_400_HZ = const(0b0111) # 400Hz
DATARATE_200_HZ = const(0b0110) # 200Hz
DATARATE_100_HZ = const(0b0101) # 100Hz
Expand All @@ -63,21 +66,31 @@

class LIS3DH:
"""Driver base for the LIS3DH accelerometer."""
def __init__(self):
def __init__(self, int1=None, int2=None):
# Check device ID.
device_id = self._read_register_byte(REG_WHOAMI)
if device_id != 0x33:
raise RuntimeError('Failed to find LIS3DH!')
# Reboot
self._write_register_byte(REG_CTRL5, 0x80)
time.sleep(0.01) # takes 5ms
# Enable all axes, normal mode.
self._write_register_byte(REG_CTRL1, 0x07)
# Set 400Hz data rate.
self.data_rate = DATARATE_400_HZ
# High res & BDU enabled.
self._write_register_byte(REG_CTRL4, 0x88)
# DRDY on INT1.
self._write_register_byte(REG_CTRL3, 0x10)
# Enable ADCs.
self._write_register_byte(REG_TEMPCFG, 0x80)
# Latch interrupt for INT1
self._write_register_byte(REG_CTRL5, 0x08)

# Initialise interrupt pins
self._int1 = int1
self._int2 = int2
if self._int1:
self._int1.direction = digitalio.Direction.INPUT
self._int1.pull = digitalio.Pull.UP

@property
def data_rate(self):
Expand Down Expand Up @@ -105,7 +118,7 @@ def range(self):
@range.setter
def range(self, range_value):
ctl4 = self._read_register_byte(REG_CTRL4)
ctl4 &= ~(0x30)
ctl4 &= ~0x30
ctl4 |= range_value << 4
self._write_register_byte(REG_CTRL4, ctl4)

Expand All @@ -125,7 +138,7 @@ def acceleration(self):

x, y, z = struct.unpack('<hhh', self._read_register(REG_OUT_X_L | 0x80, 6))

return (x / divider * 9.806, y / divider * 9.806, z / divider * 9.806)
return x / divider * 9.806, y / divider * 9.806, z / divider * 9.806

def shake(self, shake_threshold=30, avg_count=10, total_delay=0.1):
"""Detect when the accelerometer is shaken. Optional parameters:
Expand Down Expand Up @@ -184,8 +197,25 @@ def read_adc_mV(self, adc): # pylint: disable=invalid-name
@property
def tapped(self):
"""True if a tap was detected recently. Whether its a single tap or double tap is
determined by the tap param on `set_tap`. This may be True over multiple reads
even if only a single tap or single double tap occurred."""
determined by the tap param on ``set_tap``. ``tapped`` may be True over
multiple reads even if only a single tap or single double tap occurred if the
interrupt (int) pin is not specified.

The following example uses ``i2c`` and specifies the interrupt pin:

.. code-block:: python

import adafruit_lis3dh
import digitalio

i2c = busio.I2C(board.SCL, board.SDA)
int1 = digitalio.DigitalInOut(board.D11) # pin connected to interrupt
lis3dh = adafruit_lis3dh.LIS3DH_I2C(i2c, int1=int1)
lis3dh.range = adafruit_lis3dh.RANGE_8_G

"""
if self._int1 and not self._int1.value:
return False
raw = self._read_register_byte(REG_CLICKSRC)
return raw & 0x40 > 0

Expand All @@ -209,24 +239,24 @@ def set_tap(self, tap, threshold, *,
raise ValueError('Tap must be 0 (disabled), 1 (single tap), or 2 (double tap)!')
if threshold > 127 or threshold < 0:
raise ValueError('Threshold out of range (0-127)')

ctrl3 = self._read_register_byte(REG_CTRL3)
if tap == 0 and click_cfg is None:
# Disable click interrupt.
r = self._read_register_byte(REG_CTRL3)
r &= ~(0x80) # Turn off I1_CLICK.
self._write_register_byte(REG_CTRL3, r)
self._write_register_byte(REG_CTRL3, ctrl3 & ~(0x80)) # Turn off I1_CLICK.
self._write_register_byte(REG_CLICKCFG, 0)
return
# Else enable click with specified parameters.
self._write_register_byte(REG_CTRL3, 0x80) # Turn on int1 click.
self._write_register_byte(REG_CTRL5, 0x08) # Latch interrupt on int1.
if click_cfg is not None:
# Custom click configuration register value specified, use it.
self._write_register_byte(REG_CLICKCFG, click_cfg)
elif tap == 1:
self._write_register_byte(REG_CLICKCFG, 0x15) # Turn on all axes & singletap.
elif tap == 2:
self._write_register_byte(REG_CLICKCFG, 0x2A) # Turn on all axes & doubletap.
self._write_register_byte(REG_CLICKTHS, threshold | 0x80)
else:
self._write_register_byte(REG_CTRL3, ctrl3 | 0x80) # Turn on int1 click output

if click_cfg is None:
if tap == 1:
click_cfg = 0x15 # Turn on all axes & singletap.
if tap == 2:
click_cfg = 0x2A # Turn on all axes & doubletap.
# Or, if a custom click configuration register value specified, use it.
self._write_register_byte(REG_CLICKCFG, click_cfg)
self._write_register_byte(REG_CLICKTHS, 0x80 | threshold)
self._write_register_byte(REG_TIMELIMIT, time_limit)
self._write_register_byte(REG_TIMELATENCY, time_latency)
self._write_register_byte(REG_TIMEWINDOW, time_window)
Expand All @@ -250,11 +280,11 @@ def _write_register_byte(self, register, value):
class LIS3DH_I2C(LIS3DH):
"""Driver for the LIS3DH accelerometer connected over I2C."""

def __init__(self, i2c, address=0x18):
def __init__(self, i2c, *, address=0x18, int1=None, int2=None):
import adafruit_bus_device.i2c_device as i2c_device
self._i2c = i2c_device.I2CDevice(i2c, address)
self._buffer = bytearray(6)
super().__init__()
super().__init__(int1=int1, int2=int2)

def _read_register(self, register, length):
self._buffer[0] = register & 0xFF
Expand All @@ -273,11 +303,11 @@ def _write_register_byte(self, register, value):
class LIS3DH_SPI(LIS3DH):
"""Driver for the LIS3DH accelerometer connected over SPI."""

def __init__(self, spi, cs, baudrate=100000):
def __init__(self, spi, cs, *, baudrate=100000, int1=None, int2=None):
import adafruit_bus_device.spi_device as spi_device
self._spi = spi_device.SPIDevice(spi, cs, baudrate=baudrate)
self._buffer = bytearray(6)
super().__init__()
super().__init__(int1=int1, int2=int2)

def _read_register(self, register, length):
if length == 1:
Expand Down