A Practical Guide to Circuit Selection for Portable Microprocessor-Based, Low Component Count, Near-DC Ammeter for Custom Instruments

The growing market for wearable, portable, and IoT devices has generated a need for a class of circuits to meet the requirements for these applications. In this work we specifically investigate ammeters. The design space requires low component count circuits for measuring slowly varying currents using low-cost microcontrollers. Simple architectures, feasible for an electronics novice are described and compared experimentally. The use of the time domain to improve error and range of measurement is considered. This guide provides an individual without extensive electronics design experience with a simple selection guide for choosing the appropriate architecture for their specific application.