ADXL345 x Raspberry Pi をシェルスクリプトで利用する https://hankei6km.github.io/posts/2020-09-adxl345_raspberryi_pi_shellscript/

adxl345_double_tap.sh

#!/bin/sh
#
# Copyright (c) 2020 hankei6km
# Licensed under the MIT License.
# https://opensource.org/licenses/MIT

# https://www.analog.com/media/jp/technical-documentation/data-sheets/ADXL345_jp.pdf
BW_RATE="0x2c"
DATA_FORMAT="0x31"
FIFO_CTL="0x38"
POWER_CTL="0x2d"
INT_ENABLE="0x2E"
INT_MAP="0x2F"
THRESH_TAP="0x1D"
DUR="0x21"
LATENT="0x22"
WINDOW="0x23"
TAP_AXES="0x2A"
INT_SOURCE="0x30"

I2C_BUS="1"
CHIP_ADDR="0x1d"
INT1_PIN=4

i2cset -y "${I2C_BUS}" "${CHIP_ADDR}" "${BW_RATE}" 0x0b b # 200Hz
i2cset -y "${I2C_BUS}" "${CHIP_ADDR}" "${DATA_FORMAT}" 0x00 b # +-2G, RES = 10bit, INT = Active High
i2cset -y "${I2C_BUS}" "${CHIP_ADDR}" "${FIFO_CTL}" 0x00 b # bypass
i2cset -y "${I2C_BUS}" "${CHIP_ADDR}" "${POWER_CTL}" 0x08 b # Measure 8Hz
i2cset -y "${I2C_BUS}" "${CHIP_ADDR}" "${THRESH_TAP}" 0x50 b
i2cset -y "${I2C_BUS}" "${CHIP_ADDR}" "${DUR}" 0x0f b
i2cset -y "${I2C_BUS}" "${CHIP_ADDR}" "${LATENT}" 0x050 b
i2cset -y "${I2C_BUS}" "${CHIP_ADDR}" "${WINDOW}" 0xF0 b
i2cset -y "${I2C_BUS}" "${CHIP_ADDR}" "${TAP_AXES}" 0x07 b # XYZ
# i2cget -y "${I2C_BUS}" "${CHIP_ADDR}" 0x32 > /dev/null 

# i2cset -y "${I2C_BUS}" "${CHIP_ADDR}" "${INT_ENABLE}" 0x40 b # SINGLE_TAP
i2cset -y "${I2C_BUS}" "${CHIP_ADDR}" "${INT_ENABLE}" 0x20 b # DOUBLE_TAP
i2cset -y "${I2C_BUS}" "${CHIP_ADDR}" "${INT_MAP}" 0x00 b # INT1

i2cget -y "${I2C_BUS}" "${CHIP_ADDR}" "${INT_SOURCE}"  > /dev/null # CLEAR INT

while true ; do
  gpio -g wfi "${INT1_PIN}" rising
  # i2cget -y 1 0x1d "${INT_SOURCE}"

  echo "double tap"

  i2cget -y "${I2C_BUS}" "${CHIP_ADDR}" "${INT_SOURCE}" > /dev/null 
done

adxl345_get_acc.sh

#!/bin/bash
#
# Copyright (c) 2020 hankei6km
# Licensed under the MIT License.
# https://opensource.org/licenses/MIT

# https://www.analog.com/media/jp/technical-documentation/data-sheets/ADXL345_jp.pdf
BW_RATE="0x2c"
DATA_FORMAT="0x31"
FIFO_CTL="0x38"
POWER_CTL="0x2d"
INT_ENABLE="0x2E"
INT_MAP="0x2F"
THRESH_TAP="0x1D"
DUR="0x21"
LATENT="0x22"
WINDOW="0x23"
TAP_AXES="0x2A"
INT_SOURCE="0x30"

DATA_X0="0x32"
DATA_X1="0x33"
DATA_Y0="0x34"
DATA_Y1="0x35"
DATA_Z0="0x36"
DATA_Z1="0x37"

I2C_BUS="1"
CHIP_ADDR="0x1d"

# https://stackoverflow.com/questions/21051149/bash-script-convert-signed-hex-to-signed-decimal
conv() {
  RES=$(printf "%d" "${1}")
  (( RES > 32769 )) && (( RES -= 65536 )) 
  echo "${RES}"
}

get_data() {
  W=$(i2cget -y "${I2C_BUS}" "${CHIP_ADDR}" "${1}" "w")
  echo $(conv "${W}")
}


i2cset -y "${I2C_BUS}" "${CHIP_ADDR}" "${DATA_FORMAT}" 0x00 b # +-2G RES = 10bit, INT = Active High

# Range 10bit = 1024 = +- 512 -> 1G = 256
echo $(get_data "${DATA_X0}")
echo $(get_data "${DATA_Y0}")
echo $(get_data "${DATA_Z0}")