Structure of final user application

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The DALI stack is hardware independent; it calls the I/O pin driver for low level hardware

dependent functions. After initialization of the DALI stack layer (after calling initialization

functions), most of the tasks run automatically. Tasks include receiving commands and

running timer tasks (light dimming, timeouts).

Note:

For the complete source code of the DALI STACK Library, please contact your nearest sales

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2.2

I/O pin driver layer

The I/O pin driver layer of the DALI slave library implements the physical and link layers of

the DALI interface. The DALI protocol requires two pins for communication. The I/O pin

driver layer implements reception and transmission through direct control of two arbitrary

GPIO pins. It also controls the required DALI speed and correct bit timing, solves DALI bus

error recovery and gathers received bits into DALI frames (using address and command

bytes). Figure 4 displays the structure of the DALI I/O pin driver layer.

Figure 4. Structure of I/O pin driver layer

The I/O pin driver layer occupies one timer (TIM4 timer), one GPIO interrupt, one timer

interrupt, and direct control of two GPIO pins (assignment of which is software selectable).

Timing events are invoked inside the timer interrupt service routine. Such events control the

I/O pin driver layer behavior by calling callback functions from the DALI stack layer at given

1 ms intervals (timer ticks).