RGB亮度调节

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RGB亮度调节

2024-04-01 09:15| 来源: 网络整理| 查看: 265

目的

为了能更好地解决RGB三基色LED灯亮度的调节对颜色影响的问题，通常采用三路

PWM来控制三色灯的每种颜色的导通程度来实现彩色混色，调节亮度如果采用三种

基色同时递加或递减来实现亮度的调节，那么会造成颜色发生偏移问题，为了能解决

此问题，采用HSV空间颜色来实现亮度调节的

原理

首先将RGB空间颜色转换成HSV空间颜色，然后调节V的值，调整之后，再将HSV空间

颜色转回到RGB空间颜色这样就实现了三色灯亮度的调节

步骤 step 1:

在头文件中加入#include "math.h"

step 2:

定义2个结构体数据类型

//color data struct typedef struct{ unsigned char R; unsigned char G; unsigned char B; unsigned char l; }COLOR_RGB; //hsv data struct typedef struct{ float H; float S; float V; }COLOR_HSV; step 3:

定义一个COLOR_RGB结构体变量rgb_v

COLOR_RGB rgb_v; step 4:

定义2个函数，一个求最大数，一个求最小数

/**------------------------------------------------------------------------------------------------ * @brief : This is return a and b of minimum value * @param : None * @retval : None *----------------------------------------------------------------------------------------------*/ static float minValue(float a,float b) //calc minimum value { float temp = b; if(a < temp) temp = a; return temp; } /**------------------------------------------------------------------------------------------------ * @brief : This is return a and b of maximum value * @param : None * @retval : None *----------------------------------------------------------------------------------------------*/ static float maxValue(float a,float b) //calc maximum value { float temp = b; if(a > temp) temp = a; return temp; } step 5:

定义一个RGB空间颜色向HSV空间颜色转变的函数

/**------------------------------------------------------------------------------------------------ * @brief : This is RGB to HSV convert function * @param : None * @retval : None *----------------------------------------------------------------------------------------------*/ static void RGB_TO_HSV(const COLOR_RGB* input,COLOR_HSV* output) // convert RGB value to HSV value { float r,g,b,minRGB,maxRGB,deltaRGB; r = input->R/255.0f; g = input->G/255.0f; b = input->B/255.0f; minRGB = minValue(r,minValue(g,b)); maxRGB = maxValue(r,maxValue(g,b)); deltaRGB = maxRGB - minRGB; output->V = maxRGB; if(maxRGB != 0.0f) output->S = deltaRGB / maxRGB; else output->S = 0.0f; if (output->S H = 0.0f; } else { if (r == maxRGB) { output->H = (g-b)/deltaRGB; } else { if (g == maxRGB) { output->H = 2.0f + (b-r)/deltaRGB; } else { if (b == maxRGB) { output->H = 4.0f + (r-g)/deltaRGB; } } } output->H = output->H * 60.0f; if (output->H < 0.0f) { output->H += 360; } output->H /= 360; } } step 6:

定义一个HSV空间颜色向RGB空间颜色转变的函数

/**------------------------------------------------------------------------------------------------ * @brief : This is HSV to RGB convert function * @param : None * @retval : None *----------------------------------------------------------------------------------------------*/ static void HSV_TO_RGB(COLOR_HSV* input,COLOR_RGB* output) //convert HSV value to RGB value { float R,G,B; int k; float aa,bb,cc,f; if (input->S V; else { if (input->H == 1.0f) input->H = 0.0f; input->H *= 6.0f; k = (int)floor(input->H); f = input->H - k; aa = input->V * (1.0f - input->S); bb = input->V * (1.0f - input->S * f); cc = input->V * (1.0f -(input->S * (1.0f - f))); switch(k) { case 0: R = input->V; G = cc; B =aa; break; case 1: R = bb; G = input->V; B = aa; break; case 2: R =aa; G = input->V; B = cc; break; case 3: R = aa; G = bb; B = input->V; break; case 4: R = cc; G = aa; B = input->V; break; case 5: R = input->V; G = aa; B = bb; break; } } output->R = (unsigned char)(R * 255); output->G = (unsigned char)(G * 255); output->B = (unsigned char)(B * 255); } step 7:

定义一个调整亮度函数

/**--------------------------------------------------------------------------- * @brief : This is brightness adjusting function * @param : None * @retval : None *-----------------------------------------------------------------------------*/ void adjustBrightness(int step) //adjust RGB brightness { COLOR_HSV hsv_v; RGB_TO_HSV(&rgb_v,&hsv_v); rgb_v.l += step; if(rgb_v.l = 100) { rgb_v.l = 100; } hsv_v.V = rgb_v.l /100.0; HSV_TO_RGB(&hsv_v,&rgb_v); } step 8:

在main函数中测试RGB亮度调节

/**@brief Application main function. */ int main(void) { bool erase_bonds; // Initialize. // uart_init(); log_init(); timers_init(); buttons_leds_init(&erase_bonds); power_management_init(); ble_stack_init(); gap_params_init(); gatt_init(); services_init(); advertising_init(); conn_params_init(); // Start execution. // printf("\r\nUART started.\r\n"); NRF_LOG_INFO("Debug logging for UART over RTT started."); advertising_start(); // 亮度调节测试 rgb_v.R = 0xef; rgb_v.G = 0x36; rgb_v.B = 0x86; rgb_v.l = 0x64; adjustBrightness(-30); //亮度减少30% //打印转换后的RGB值及亮度值 NRF_LOG_INFO("R=%02x,G=%02x,B=%02x,L=%02x\n",rgb_v.R, rgb_v.G ,rgb_v.B,rgb_v.l); // Enter main loop. for (;;) { idle_state_handle(); } }

DEMO下载地址：https://download.csdn.net/download/mygod2008ok/11180344

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RGB亮度调节

RGB亮度调节

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