Embedded Lab

This Arduino-powered 8-channel data logger built by smooth_jamie can measure AC currents drawn by home appliances or other equipments, and record the data on an SD card with timestamp for future use. The project uses the HMCT103C 5A/5MA current transformer for sensing the current flowing through a conducting wire. The current transformer output signal is very low, and therefore, an OpAmp-based circuit is built for instrumentation. The analog output voltages corresponding to the eight-channel current logger are digitized using an external lADS1115 16-bit A/D converter IC.

Hi Everyone, welcome to my first instructable! By day I am a test engineer for a company that supplies industrial heating equipment, by night I am an avid technology hobbyist and DIY’er. Part of my work involves testing the performance of heaters, on this occasion I wanted to be able to monitor the RMS current draw of 8 devices over 1000hrs and log the data to graph the results later. I have access to a data logger but it was already committed to another project and I needed something low cost, so I decided to cobble together this basic datalogger.

The project uses an Arduino Uno to read analogue sensors via analogue to digital converter (ADC) and records the data with a time stamp on an SD card. There is alot of theory and calculation involved in designing the circuits, so instead of explaining absolutely everything, I will just show you how to make it. If your interested in seeing the FULL hit then let me know in the comments and I will explain further.