AN1756 is an official application note released by ST. It introduces how to use ST7DALIF2 microcontroller to implement DALI (Digital Addressable Lighting Interface) protocol. This document introduces the implementation methods of DALI protocol and provides detailed information about the advantages of DALI protocol.
This document describes strategies for implementing the Digital Addressable Lighting Interface (DALI) protocol using the ST7DALIF2 microcontroller. It details two main topologies: one where the microcontroller handles only communication alongside a ballast controller, and another where it replaces the driver control entirely.
The note also provides an introduction to the DALI standard, including its bi-phase Manchester asynchronous serial data format, transmission rates, frame structures (forward and backward), and system advantages such as simple wiring and easy re-configuration.
| Transmission rate (bandwidth) | 1.2 kHz |
|---|---|
| Bi-phase bit period | 833.33uS +10% |
| Forward frame size | 19 bits |
| Backward frame size | 11 bits |
| Settling time between forward frames | 9.17 ms (minimum) |
The ST7DALIF2 microcontroller has a dedicated peripheral for handling the DALI protocol, allowing it to manage communication and potentially replace the driver control in high-frequency tube lamp ballast applications.
The transmission rate is about 1.2 kHz.
A maximum of 16 scenes can be defined.
All units are interconnected using a simple five-core cable.