A USB-Enabled, FLASH-Disk-Based Data Logger
Shlomo Engelberg, Tzvi Kaminsky, Moshe Horesh · 2007
data logger is a device for measuring and storing data. It is an all-purpose piece of measurement equipment that finds use in an extremely wide range of applications. In principle, a data logger is a relatively simple piece of equipment; as always, the devil is in the details. A well-constructed data logger should be a joy to work with; a poorly designed data logger can easily drive an engineer to tears. Data loggers, in one form or another, have existed for many years. In this article, we describe a reasonably easy to implement data logger that makes measurements using a microcontroller’s on-chip analog-to-digital converter (ADC) and makes use of two rather new technologies. Our data logger stores data on a removable FLASH disk, and it knows how to communicate with a computer using the universal serial bus (USB) standard. Our design was helped immeasurably by the fine folks at Microchip who developed the PIC18F4550, the PICDEM FS USB board, and the PICtail board. The PIC18F4550 and the PICDEM FS USB board are designed to allow the user to design USB-enabled products. The PICtail board allows the user to connect the PIC microcontroller to a multimedia card (MMC) or to a secure digital (SD) card— two (very popular) types of FLASH disks. In this article, we describe the data logger and the various parts that we used to implement it. When you finish reading this article, you should be about ready to start developing similar projects.