Introduction For an upcoming research project, I needed to get data streams from simple 2-axis accelerometers. There are usually two types of accelerometers: one type with analog outputs that need an ADC (analog-digitial converter) to sample, and another type with pulse-width modulation outputs. The latter has the advantage that it can be sampled with purely digital inputs like the standard parallel port of current PCs. Thus, the crazy idea of attaching accelerometers directly to the parallel port instead of using a micro controller was born.
Motivation Suspend, a.k.a. hibernate, is an important method for usability of today’s laptops. There are essentially two flavors with different implications on security:
Suspend-to-RAM (ACPI S3): This means that the processes are frozen, and all hardware components besides the main RAM (and minimal activity do refresh the DRAM cells) are turned off. This includes the display, the harddisk, and all peripheral components, and thus typically saves the majority of the power.