KST is a useful desktop program available on Linux and Windows for graphing and data analysis of CSV data. It can be used to graph the output of OpenEnergyMonitor hardware connected directly via serial, the following guide details how to set this up with an emontx running standard firmware.
"Kst is the fastest real-time large-dataset viewing and plotting tool available and has basic data analysis functionality. Kst contains many powerful built-in features and is expandable with plugins and extensions. Extensive help is available, both from within kst and on the web. Kst is a KDE application and is freely available for anyone to download and use." - KST Website
In a terminal window type: sudo apt-get install kst
If you're a windows user, KST can be downloaded here
Save the following program to a file, lets call it: serial_to_csv.py
#!/usr/bin/python import serial, sys, string ser = serial.Serial('/dev/ttyUSB0', 9600) while 1: # Read in line of readings from emontx serial linestr = ser.readline() # Remove the new line at the end # linestr = linestr.rstrip() # Replace space with comma for CSV linestr.replace(" ",",") # Append line to file with open("mydata.csv", "a") as myfile: myfile.write(linestr) # Output line to terminal window print linestr