From d188ecb3f71b382ee2a8b090f45d3b35358f8f75 Mon Sep 17 00:00:00 2001
From: Bryan <bryan@tnet.space>
Date: Fri, 1 Jan 2021 19:35:14 -0600
Subject: [PATCH] start extracting stuff to make functions available as library

---
 chip-battery.sh | 142 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 142 insertions(+)
 create mode 100644 chip-battery.sh

diff --git a/chip-battery.sh b/chip-battery.sh
new file mode 100644
index 0000000..9926f3a
--- /dev/null
+++ b/chip-battery.sh
@@ -0,0 +1,142 @@
+#!/bin/bash/
+#
+# @author Raoul R., 2016
+#
+# This script watches (polls) the battery state and the gpio $POWER_BUTTON_GPIO pin level. 
+# If pin is pulled to GND the script initiates a shut down.
+#
+
+# SHUTDOWN_MIN_BATTERY_VOLTAGE ... [mV]
+SHUTDOWN_MIN_BATTERY_VOLTAGE=2100.0
+# SHUTDOWN_MIN_BATTERY_VOLTAGE ... [mA]
+SHUTDOWN_MIN_BATTERY_CURRENT=20.0
+
+# see http://docs.getchip.com/#how-you-see-gpio
+POWER_BUTTON_GPIO_NUMBER="414"
+POWER_BUTTON_GPIO="/sys/class/gpio/gpio$POWER_BUTTON_GPIO_NUMBER"
+
+# LOG_LEVEL ... DEBUT | INFO
+LOG_LEVEL="DEBUG"
+
+TRUE=1
+FALSE=0
+
+
+# $1 ... message
+# debug log
+function log() {
+  if [ "$LOG_LEVEL" = "DEBUG" ] ; then
+    local message=$1
+    logger -t "PME" "$message"
+  fi
+}
+
+# $1 ... message
+# more verbose information logging
+function logInfo() {
+  local message=$1
+  logger -t "PME" "$message"
+}
+
+function setupGpioInputButton()
+{
+  if [ ! -e ${POWER_BUTTON_GPIO} ] ; then
+    echo "$POWER_BUTTON_GPIO_NUMBER" > /sys/class/gpio/export
+  fi
+  echo "in" > ${POWER_BUTTON_GPIO}/direction > /dev/null 2>&1
+  echo "0" > ${POWER_BUTTON_GPIO}/active_low > /dev/null 2>&1
+}
+
+function cleanupGpioInputButton() {
+  echo "$POWER_BUTTON_GPIO_NUMBER" > /sys/class/gpio/unexport
+}
+
+# $1 ... message
+function shutdownCommand() {
+  logInfo "$1"
+  cleanupGpioInputButton
+  setLed 1
+  shutdown -h 0 &
+  exit 0
+}
+
+# @return ... 0,1 as return value
+function isBatteryAvailable() {
+  local flags=$(i2cget -f -y 0 0x34 0x01)
+  return $(((( $flags&0x20 ) >>5 ) == $TRUE ))
+}
+
+# @return ... voltage as string
+function getBatteryVoltage() {
+  local voltageHighByte=$(i2cget -y -f 0 0x34 0x78)
+  local voltageLowByte=$(i2cget -y -f 0 0x34 0x79)
+  local rawVoltage=$(($(($voltageHighByte << 4)) | $(($(($voltageLowByte & 0x0F ))))))
+  echo "($rawVoltage * 1.1)" | bc
+}
+
+# @return ... charging current as string
+function getChargeCurrent() {
+  local currentHighByte=$(i2cget -f -y 0 0x34 0x7A)
+  local currentLowByte=$(i2cget -f -y 0 0x34 0x7B)
+  local rawCurrent=$(($(($currentHighByte << 4)) | $(($(($currentLowByte & 0x0F))))))
+  echo "($rawCurrent * 0.5)" | bc
+}
+
+# shuts the system down if too less voltage
+function verifyBatteryVoltage() {
+  isBatteryAvailable
+  if [ "$?" -eq "1" ] ; then
+      local voltage=$(getBatteryVoltage)
+      chargeCurrent=$(getChargeCurrent)
+      log "battery charge current [${chargeCurrent}mV] min current [${SHUTDOWN_MIN_BATTERY_CURRENT}mV]"
+      if [ $(echo "$voltage <= $SHUTDOWN_MIN_BATTERY_VOLTAGE" | bc) -eq "1" ] ; then
+          log "critical battery voltage [${voltage}mV] min voltage [${SHUTDOWN_MIN_BATTERY_VOLTAGE}mV]"
+          if [ $(echo "$chargeCurrent <= $SHUTDOWN_MIN_BATTERY_CURRENT" | bc) -eq "1" ] ; then
+              shutdownCommand "shutting down due to low voltage/charge current"
+          fi
+          return
+      fi
+      log "battery voltage [${voltage}mV] min voltage [${SHUTDOWN_MIN_BATTERY_VOLTAGE}mv]"
+  fi
+}
+
+# $1 ... led state (0,1)
+function setLed() {
+  if [ "$1" -eq "1" -o "$1" -eq "0" ] ; then
+    /usr/sbin/i2cset -f -y 0 0x34 0x93 0x$1
+  fi
+}
+
+# @return ... true if button pressed else false as return value
+function isButtonPressed() {
+  local value=$(cat ${POWER_BUTTON_GPIO}/value)
+  
+
+  
+  if [ "$value" -eq "0" ] ; then
+    shutdownCommand "shutdown on button pressed"
+  fi
+}
+
+function verifyButton() {
+  isButtonPressed
+  if [ "$?" -eq "1" ] ; then
+    shutdownCommand "shutdown on power button request"
+  fi
+}
+
+function main() {
+  setupGpioInputButton
+  
+  while true ; do
+    setLed 1
+    verifyBatteryVoltage
+    verifyButton
+    setLed 0
+    sleep 3
+  done
+}
+
+# start monitoring in subshell and nonblocking
+$(main)&
+exit 0