Embedded Glossary

The Raspberry Pi is a single-board computer that combines a processor, working memory, and numerous interfaces on a compact printed circuit board. Its central component is a system-on-chip from Broadcom based on the ARM architecture, capable of running a full-featured operating system such as Embedded Linux. A pin header provides digital inputs and outputs as well as serial buses for connecting sensors, displays, and other peripherals. Originally designed for educational purposes, it is now often used as a readily available platform for prototypes and small production runs. For long-lived products, the guaranteed availability period and suitability for the industrial temperature range require careful evaluation. Its broad ecosystem of accessories and active community significantly lowers the barrier to entry for embedded systems development.

Real-time describes an embedded system’s ability to react to events within a precisely defined period. RTOS, RTLinux and VxWorks support this behavior where exceeding the maximum response time can cause damage. Latency is the response time, while jitter is its deviation from the mean. Real-time behavior supports dependable embedded operation.

Reconnect restores a previously interrupted network or device connection. A detected connection loss or a Timeout triggers a new connection attempt. Limited retries with increasing delays reduce unnecessary load on the device and network. Controlled reconnect handling maintains availability during temporary disruptions.

A regression is an unintended deterioration or a recurring fault in software that was already working after a change. It can result from modifications to firmware, drivers or configurations and impair previously fault-free device functions. Clear modularization and regression tests identify such side effects early.

An RT Patch extends the Linux kernel with PREEMPT_RT mechanisms for more predictable timing. It makes many kernel sections preemptible and shifts most Interrupt handling to prioritised threads. This reduces Latency and jitter. RT Patches enable real-time responses on Embedded Linux systems.

RTOS stands for Real-Time Operating System and is an operating system that plans tasks according to priorities and complies with binding time limits. It enables predictable reactions to events and limits latency as well as jitter. RTOS is the basis for critical control systems with fixed timing behaviour.