main

#!/bin/bash
#
# Displaying the current time using AQM0802

# Check and rewrite I2C address
readonly DEVICE="0x3e"

#######################################
# Convert string to hexcode
# Globals:
#   None
# Arguments:
#   string
# Returns:
#   hexcode
#######################################
function convert_hexcode() {
  local string="$1"
  local hexcode=""

  if [[ ${#string} -ne 0 ]]; then
    for index in $(seq 0 $((${#string} - 1))); do
      hexcode="${hexcode} 0x$(printf "%x" \'${string:${index}:1})"
    done
  fi

  echo ${hexcode}
}

# aqm0802 initialization
i2cset -y 1 ${DEVICE} 0 0x38 0x39 0x14 0x70 0x56 0x6c i
sleep 0.2
i2cset -y 1 ${DEVICE} 0 0x38 0x0c 0x01 i
sleep 0.2

while true; do
  now=$(LANG=en_US.UTF-8 date '+%m/%d%a%H:%M:%S')

  # display 1st line
  display1="$(convert_hexcode ${now:0:8})"
  i2cset -y 1 ${DEVICE} 0x40 ${display1} i
  i2cset -y 1 ${DEVICE} 0 0xc0 b

  # display 2nd line
  display2="$(convert_hexcode ${now:8:8})"
  i2cset -y 1 ${DEVICE} 0x40 ${display2} i
done