energy-scribe

kwh meter reading and logging

Target device is Raspberry Pi version 2 or later. Electrical meter with serial or modbus adapter is connected to RaPi. Uses RaPi blinkt LED hardware shield for status display. Currently supports Current Cost CC128 energy monitor, Hiking DDS238-2 ZN/S single phase meter and Schneider iEM2150 single phase meter. The project consists of the following files:

auto.sh

A script that should be configured to auto start on power up. Displays IP address on the blinkt display twice and then calls the continuous_read.py program. This script will restart itself if the continuous_read.py program terminates.

continuous_read.py

Provides a timed loop to read from meter(s) and write values to USB stick. Indicates running status/health on LED blinkt shield. Calls a sub-process to actually acquire the readings, collecting from the sub-process stdout. Edit this file to point to a different acquisition program or to change the path for data logging. Default is to log data to a new CSV file in a kwhmeter folder on a USB stick. Will recover and reconnect if there is a temporary interruption or disconnection of the serial interface. Will exit with error 1 if the USB stick is detached or path not found.

Status LEDs:

• 0 Purple: program is running, Red: program halted
• 1 Green: acquisition running, Red: acquisition failed
• 2 Blue: log writing, Red: log writing failed.

blinkt_display_ip_address.py

Reads out the device IP address as a succession of coloured LED codes.

• 0 = two blue LEDs, centred.
• 1-8 = one to eight blue LEDs.
• 9 = Three blue leds, gap, three blue leds.
• DOT = Two white leds.

blinkt_indicator.py

Test the blinkt hardware. Usage: ./blinkt_indicator.py 2 red turns LED 2 red. ./blinkt_indicator 2 off turns LED 2 off.

schneider_iEM2150.py

Read one line of electrical values (V, A, kW, kVAR, pf, pf_direction, freq, kWh) from the Schneider iEM2150 modbus meter. Write values to stdout as CSV text with timestamp.

current_cost.py

Read one line of power values (W) from up to nine wireless current cost meters connected to the base station. Writes vaules to stdout as CSV text with timestamp.

hiking_dds238_2.py

Read one line of electrical values (V, A, W, VAR, pf, freq, kWh) from the Hiking DDS238-2 modbus meter. Write values to stdout as CSV text with timestamp.

The python tools have dependencies on the following libraries that need to be installed:

• blinkt Operates the Blinkt LED shield that attaches to Raspberry Pi
• minimalmodbus Modbus library on top of serial bus
• posix_ipc Enables cooperative sharing of comms port between processes running in parallel ('semaphore' versions of acquisition programs)