Create SD Image Version 0.8.4

Install gnuplot

sudo apt-get install gnuplot

add -r Retries option to driver wrappers

The maximum number of retries to read a sensor before giving up can be specified.

The shell script wrappers around the sensor drivers (dht22.sh, hx711.sh, hx711py.sh, etc) now accept a -r retries command line argument.

#
# Get the command line options (which device/GPIO pin to read), maximum number of times to try reading the sensor
#
while getopts "d:r:" option
do
        case "${option}"
        in
                d) DEVICE=${OPTARG};;
                r) MAXRETRIES=${OPTARG};;
        esac
done 

#
# If max number of retires not specified, default to 10
#
if [ -z $MAXRETRIES ]
then
  MAXRETRIES=10
fi 

#echo "DEVICE = $DEVICE"
#echo "MAXRETRIES = $MAXRETRIES"
#
# Loop up to MAXRETRIES times trying to read the sensor
#

DATA_GOOD=0
COUNTER=0
while [ $COUNTER -lt $MAXRETRIES ] && [ $DATA_GOOD -eq 0 ]
do
                      ....