Nowadays, homemade electronic products on microcontrollers are trendy. I am even more interested in assembling different devices on simple logic circuits. Their operating principle is more visual, which gives me aesthetic pleasure. Today we are going to show you four simple devices. Three of them are based on triggers, and the fourth one, which we will start with, could use a trigger.
Wired lighting protocols include KNX for smart homes on 9.6 kbps twisted pair; reliable but costly, usually commissioned by specialists and linked to DALI via gateways. DMX512/RDM over RS-485 at 250 kbps enables fast stage effects. SPI is common for LED strips but lacks standardization. Power-line options: X10 is obsolete; PLC/PLC-DC is used for street and industrial controls where RF issues arise.
Resistive moisture sensors use exposed PCB traces to detect water. Rain needs AC because near‑distilled drops have high resistance. An inverting Schmitt‑trigger oscillator drives the sensor; a high‑pass, gain stages, rectifier, and integrator yield a logic level that lights an LED or actuates gear like a sunroof. The build demos a KD9561 sound chip. Notes touch solder, lead, and thin gold plating.
DALI (Digital Addressable Lighting Interface) is a two-wire digital protocol for controlling up to 64 devices per bus, scalable to thousands. It uses simple cabling with flexible topology and supports two-way communication for control and status monitoring. Its limitations include command delay preventing dynamic effects and the need for a gateway for smart home integration. Evolving standards include DALI-2 for human-centric lighting and DALI+ for IP-based control.
Smart lighting uses digital protocols for automated control, enabling features like individual fixture addressing, light scenes, and two-way communication for status monitoring. It integrates with smart home systems via protocol converters. Benefits include enhanced comfort through predictive lighting and biodynamic cycles, increased energy efficiency, and new functionalities like voice control and AI-driven automation that learns user habits.
