Brightness control and dimming logic for button device. More...

Topics
	Brightness Constants

Functions
uint8_t	ad_btn_dim_GetNewValue (uint32_t dimLevel)
	Calculate new brightness value based on current dim level.

Detailed Description

Brightness control and dimming logic for button device.

Overview

This module implements adaptive brightness control with configurable thresholds and step sizes. The dimming behavior changes based on current brightness level - brighter levels use larger steps for faster adjustment, while darker levels use smaller steps for fine control.

Algorithm Description

The brightness adjustment uses two lookup tables:

threshTab: Defines brightness range boundaries (thresholds)
stepsTab: Defines adjustment step size for each range

When adjusting brightness, the algorithm:

Determines current brightness range using threshTab
Selects appropriate step size from stepsTab
Increments/decrements brightness by that step

Customizing Brightness Behavior

Modifying Brightness Thresholds

Edit the threshTab[] array to change brightness range boundaries:

// Default configuration (5 ranges)
static const uint8_t threshTab[OT_BTN_LEVELS_COUNT] = {30, 80, 160, 220, OT_BTN_MAX_BRIGHTNESS};
 
// Custom configuration - more ranges for finer control
#define OT_BTN_LEVELS_COUNT 7
static const uint8_t threshTab[OT_BTN_LEVELS_COUNT] = {20, 50, 100, 150, 200, 230, OT_BTN_MAX_BRIGHTNESS};

Modifying Brightness Steps

Edit the stepsTab[] array to change adjustment speed for each range:

// Default configuration
static const uint8_t stepsTab[OT_BTN_LEVELS_COUNT] = {1, 4, 6, 8, 16};
 
// Custom - slower dimming for more precise control
static const uint8_t stepsTab[OT_BTN_LEVELS_COUNT] = {1, 2, 3, 4, 8};
 
// Custom - faster dimming for quick adjustment
static const uint8_t stepsTab[OT_BTN_LEVELS_COUNT] = {2, 8, 12, 16, 32};

Modifying Brightness Limits

Adjust minimum and maximum brightness values:

#define OT_BTN_MAX_BRIGHTNESS 200 // Reduce maximum brightness to 78%

#define OT_BTN_MIN_BRIGHTNESS 10 // Increase minimum visible brightness

Configuration Examples

Smooth Fine Control

#define OT_BTN_LEVELS_COUNT 8
static const uint8_t threshTab[] = {15, 30, 60, 90, 120, 160, 200, 255};
static const uint8_t stepsTab[] = {1, 1, 2, 3, 4, 6, 8, 12};

Fast Adjustment

#define OT_BTN_LEVELS_COUNT 3
static const uint8_t threshTab[] = {85, 170, 255};
static const uint8_t stepsTab[] = {10, 20, 40};

Note: Both arrays must have exactly OT_BTN_LEVELS_COUNT elements; Last element of threshTab must equal OT_BTN_MAX_BRIGHTNESS; Array elements must be in ascending order

Warning: After modifying tables, recompile the entire project to ensure consistency

Version: 0.1

Date: 06-11-2025

Author: Jan Łukaszewicz (plhar.nosp@m.eo@g.nosp@m.mail..nosp@m.com)

Function Documentation

◆ ad_btn_dim_GetNewValue()

uint8_t ad_btn_dim_GetNewValue ( uint32_t dimLevel )

Calculate new brightness value based on current dim level.

Parameters

[in] dimLevel Current brightness level (0-255) or direction indicator

Returns: New brightness value after applying appropriate step adjustment

Return values

0	if brightness drops below OT_BTN_MIN_BRIGHTNESS (turns off)
OT_BTN_MAX_BRIGHTNESS	if brightness exceeds maximum

This function implements the adaptive brightness algorithm:

Identifies current brightness range using threshTab[]
Selects step size from stepsTab[]
Applies adjustment in dimming or brightening direction
Ensures result stays within valid range

Note: Function handles both dimming (decreasing) and brightening (increasing) operations

Topics

Functions