Battery Monitor EZ-Script

# Battery Monitor Script
# Author: Rich
# Date: 2013-07-09
# Version: 1.1.3

# Read voltage level of a single battery pack and report to software.
# Adapted from LiPo monitor circuit.
# Assumed monitor circuit connected to ADC0

# Additional LCD Display code added
# Assumed 16x2 I2C LCD Display
# as http://www.robot-electronics.co.uk/acatalog/LCD_Displays.html

# Additional code for automatic voltage level calculations for
# Lead Acid battery discharge voltages.

# Set variables
# Change $multiplyer if using voltage divider
# Factor is 5/255 for adc value conversion to volts

# Voltage Monitor Details
$multiplier = 4
# Lead Acid Battery Voltage
$vbat = 12

# Default values. Vmin at 20%. Vcritical at 10%.
# Level1 40%, Level2 60%, Level3 80%
# Change if required. Note levels are on a curve.
$vundervoltage = $vbat*0.88
$vcritical = $vbat*0.94
$vmin = $vbat*0.97
$level1 = $vbat*0.99
$level2 = $vbat*1.02
$level3 = $vbat*1.04
$vmax = $vbat*1.06
$factor = 0.019607843

:ReadCells
# Get ADC values
$vc1 = GetADC(ADC0)

# Convert values to voltage to 2 decimal places
$batterylevel = $vc1 * $factor
$batterylevel = $batterylevel * $multiplier
$batterylevel = Round($batterylevel,2)

# Check for errors on circuit
IF ($batterylevel > $vmax)
  Print("Battery Monitor Error")
  Print("Check Monitor Circuits")
  # I2CWrite code for displaying message on LCD

  # Check for errors on battery connection
ELSEIF ($batterylevel <= 0)
  Print ("Battery Connection Error")
  Print("Check Battery Connection")
  # I2CWrite code for displaying message on LCD

  # Check for under voltage
ELSEIF ($batterylevel <= $vundervoltage)
  Print ("Battery Under Voltage")
  Print("Check Or Replace Battery")
  # I2CWrite code for displaying message on LCD

  # Check if at critical levels
ELSEIF ($batterylevel <= $vcritical)
  # Do sometihing if critical
  Print("Battery Critical")
  # I2CWrite code for displaying message on LCD
  # Shut down all power, switch to back up battery alarm?

  # Check if below recommended levels
ELSEIF ($batterylevel < $vmin)
  # Do sometihing if voltage low
  # Battery 60% full, display 0 full blocks and 5 empty block
  Print("Battery Level Low")

ELSE
  # Output voltages
  Print($batterylevel + "V")
  # Output to LCD display here
  IF ($batterylevel >= $vmax)
    # Battery Full, display 5 full blocks and 0 empty blocks
  ELSEIF ($batterylevel > $level3)
    # Battery 80% full, display 4 full blocks and 1 empty block
  ELSEIF ($batterylevel > $level2)
    # Battery 60% full, display 3 full blocks and 2 empty blocks
  ELSEIF ($batterylevel > $level1)
    # Battery 40% full, display 2 full blocks and 3 empty blocks
  ELSEIF ($batterylevel > $vmin)
    # Battery 20% full, display 1 full block and 4 empty blocks
  ENDIF
ENDIF
# Wait 5 seconds
Sleep(5000)

# Go back to the start
Goto(ReadCells)