Tools for Nessie Circuits energy harvesting recorder

The energy harvesting recorder records voltage and current of two energy harvesters (AC and DC) as well as accelerometer readings. The tools in this repository are used to convert recorded data to csv or hdf files for analysis and further processing. There's also a command to convert a harvesting trace to a format compatible with the Nessie Circuits SolarBox.

Installation

Install the python package using either

pip install nessie.recorder

or

pipenv install nessie.recorder

Data extraction

To convert the file REC_001.DAT recorded with an EH recorder to a csv output file:

nessie-recorder extract -i REC_001.DAT -o out.csv

Extracting to csv requires to load all recorded data into memory, which may not work for very large files.

As an alternative, convert the file REC_001.DAT to an hdf5 output file:

nessie-recorder extract -i REC_001.DAT -o out.h5

Plotting

To plot the extracted data:

nessie-recorder plot -i out.csv

If your recording is very long, you won't be able to load all data into memory for plotting. If you extracted your data to hdf5, you can plot the downsampled (e.g., every 100th sample) data with:

nessie-recorder plot -i out.h5 -d 100

Conversion to SolarBox

You can convert an EH recorder trace to a SolarBox trace to replay it to an energy harvesting device. For this purpose, you will need a mapping of the SolarBox input value (0-100%) to the resulting power of a panel mounted inside. This mapping must be formatted as a csv file with two columns: solarbox and recorder in percent and watts respectively.

solarbox,recorder
0,8.4833230555061e-08
10,0.00768804210057344
20,0.015250790089624976
30,0.022412615156234474
40,0.029180363344797327

With this mapping stored under mapping.csv, you can convert the recorder trace recorded.csv to a SolarBox trace solarbox.csv using:

nessie-recorder convert -i recorded.csv -o solarbox.csv -m mapping.csv

Example Configuration

This directory also contains an example configuration file ./CONFIG.INI for use with the EH recorder. Adjust it to your needs and store it on the top level of a FAT32-formatted SD Card under the name CONFIG.INI.