如何利用CX32L003的pwm调节灯光颜色？看完秒懂
#申请原创# @21小跑堂在使用CX32L003的pwm功能后，我们用的是涂鸦模组做调光的灯光类产品的开发，因为调光是根据涂鸦模组app调节不同的灯光亮度，颜色渐变达到炫丽的灯光颜色变化，所以对pwm要灵活的调节占空比达到光，色，亮度相互饱和的效果。
以上显示的是灯带的R,G,B颜色渐变的效果，这个RGB的颜色是根据HSV颜色体系进行转换得到的，HSV(hue,saturation,value)颜色空间的模型对应于圆柱坐标系中的一个圆锥形子集，圆锥的顶面对应于V=1. 它包含RGB模型中的R=1，G=1，B=1 三个面，所代表的颜色较亮。色彩H由绕V轴的旋转角给定。红色对应于 角度0° ，绿色对应于角度120°，蓝色对应于角度240°。在HSV颜色模型中，每一种颜色和它的补色相差180° 。 饱和度S取值从0到1，所以圆锥顶面的半径为１。HSV颜色模型所代表的颜色域是CIE色度图的一个子集，这个 模型中饱和度为百分之百的颜色，其纯度一般小于百分之百。在圆锥的顶点(即原点)处，V=0,H和S无定义， 代表黑色。圆锥的顶面中心处S=0，V=1,H无定义，代表白色。从该点到原点代表亮度渐暗的灰色，即具有不同 灰度的灰色。对于这些点，S=0,H的值无定义。可以说，HSV模型中的V轴对应于RGB颜色空间中的主对角线。 在圆锥顶面的圆周上的颜色，V=1，S=1,这种颜色是纯色。
也就是说这里H的范围是0~360，而S和V分别是对应0-1000。这里我们把定时器的pwm设置成1kHz,占空比从0-1000范围可调。这里我用TIM2来初始化R,G,B的pwm。static void Timer2PwmInit(uint16_t arr,uint16_t psc)
{
/*
//PC5复用TIM2_CH1
GPIOC->AFR &= 0XFF0FFFFF;//
GPIOC->AFR |= 0X00800000;
GPIOC->PUPDR &= 0XFFFFF3FF;
GPIOC->PUPDR |= 0X00000800;//
*/
//PC5_TIM2-CH1
/*
GPIOC->DIRCR &= 0XFFFFFFDF;
GPIOC->DIRCR |= 0X00000020;
*/
/*
//PD3复用TIM2_CH2
GPIOD->AFR &= 0XFFFF0FFF;//
GPIOD->AFR |= 0X00008000;
GPIOC->PUPDR &= 0XFFFFFF3F;
GPIOC->PUPDR |= 0X00000020;//
*/
//PD3_TIM2_CH2
/*
GPIOD->DIRCR &= 0XFFFFFFF7;
GPIOD->DIRCR |= 0X000000F8;
*/
/*
TIM1->ARR = arr;//设定计数器自动重装值
TIM1->PSC = psc;//预分频器不分频
TIM1->CCMR1 |= 7<<12;//OC2模式 TIM1_CH3,TIM1_CH4
TIM1->CCMR1 |= 1<<11; //CH4预装载使能
TIM1->CCER|= 1<<4; //OC2 输出使能
TIM1->CR1 = 0x0080; //ARPE使能
TIM1->CR1 |= 0x01;//使能定时器1
///TMR3->CC4 = BK_LEVEL3;///BK_LEVEL_MOST_LOWER;
setPwmVol(TIM1,1000-1);//即90% 占空比
setPwmTone(TIM1,1000-1);
*/
GPIO_InitTypeDef gpioInitStruct;
///TIM_HandleTypeDef tim2InitStruct;
///TIM_OC_InitTypeDeftim2OcInitStruct = {0};
__HAL_RCC_TIM2_CLK_ENABLE();
__HAL_RCC_GPIOA_CLK_ENABLE();
__HAL_RCC_GPIOC_CLK_ENABLE();
__HAL_RCC_GPIOD_CLK_ENABLE();
gpioInitStruct.Pin = TIM2_CH1OUT_PIN;
gpioInitStruct.Mode = GPIO_MODE_AF;
gpioInitStruct.Pull = GPIO_PULLDOWN;
gpioInitStruct.OpenDrain = GPIO_PUSHPULL;
gpioInitStruct.Debounce.Enable = GPIO_DEBOUNCE_DISABLE;
gpioInitStruct.SlewRate = GPIO_SLEW_RATE_HIGH;
gpioInitStruct.DrvStrength = GPIO_DRV_STRENGTH_HIGH;
gpioInitStruct.Alternate = TIM2_CH1OUT_GPIO_AFN;
HAL_GPIO_Init(TIM2_CH1OUT_PORT, &gpioInitStruct);
gpioInitStruct.Pin = TIM2_CH2OUT_PIN;
gpioInitStruct.Alternate = TIM2_CH2OUT_GPIO_AFN;
HAL_GPIO_Init(TIM2_CH2OUT_PORT, &gpioInitStruct);
gpioInitStruct.Pin = TIM2_CH3OUT_PIN;
gpioInitStruct.Alternate = TIM2_CH3OUT_GPIO_AFN;
HAL_GPIO_Init(TIM2_CH3OUT_PORT, &gpioInitStruct);
sTim2_Handle.Instance = TIM2;
sTim2_Handle.Init.Period = arr;// TIM1_ARR 周期
sTim2_Handle.Init.Prescaler = psc;// 计数器的时钟频率(CK_CNT)等于fCK_PSC/(PSC+1) 即计数器的时钟频率=TIMx_FREQ
sTim2_Handle.Init.ClockDivision = 0;// CKD 时钟分频因子(Clock division)
sTim2_Handle.Init.CounterMode = TIM_COUNTERMODE_UP; // 边沿对齐模式 计数器向上计数
sTim2_Handle.Init.RepetitionCounter = 0;// TIM1_RCR 重复计数器的值
sTim2_Handle.Init.AutoReloadPreload = TIM_AUTORELOAD_PRELOAD_DISABLE; // 禁止自动重装载
HAL_TIM_PWM_Init(&sTim2_Handle);
sTim2_OcInitHandle.OCMode = TIM_OCMODE_PWM1; // PWM模式1 TIM1_CCMR1
// sTim1_OcInitHandle.OCPolarity = TIM_OCPOLARITY_LOW; // 输出极性 OC1低电平有效
// sTim1_OcInitHandle.OCNPolarity = TIM_OCNPOLARITY_LOW; // OC1N低电平有效
// sTim1_OcInitHandle.OCFastMode = TIM_OCFAST_ENABLE; // 输出比较1清’0’使能
// sTim1_OcInitHandle.OCIdleState = TIM_OCIDLESTATE_RESET; // MOE=0时，如果实现了OC1N，则死区后OC1=0；
// sTim1_OcInitHandle.OCNIdleState = TIM_OCNIDLESTATE_RESET; // MOE=0时，死区后OC1N=0
///tim1OcInitStruct.Pulse = TIM1_CH1_PULSEWIDTH; // CCR 捕获/比较通道 // 占空比值
///tim1OcInitStruct.Pulse = TIM1_CH2_PULSEWIDTH;
sTim2_OcInitHandle.Pulse = TIM2_CH1_PULSEWIDTH;
HAL_TIM_PWM_ConfigChannel(&sTim2_Handle, &sTim2_OcInitHandle, TIM_CHANNEL_1);
sTim2_OcInitHandle.Pulse= TIM1_CH2_PULSEWIDTH;
HAL_TIM_PWM_ConfigChannel(&sTim2_Handle, &sTim2_OcInitHandle, TIM_CHANNEL_2);
sTim2_OcInitHandle.Pulse= TIM2_CH3_PULSEWIDTH;
HAL_TIM_PWM_ConfigChannel(&sTim2_Handle, &sTim2_OcInitHandle, TIM_CHANNEL_3);
/*##-3- Start PWM signals generation #######################################*/
/* Start channel 1 */
HAL_TIM_PWM_Start(&sTim2_Handle, TIM_CHANNEL_1);
/* Start channel 2 */
HAL_TIM_PWM_Start(&sTim2_Handle, TIM_CHANNEL_2);
/* Start channel 3 */
HAL_TIM_PWM_Start(&sTim2_Handle, TIM_CHANNEL_3);
/* Start channel 4 */
}那么S和V就是直接调节占空比得到，而S是根据一个圆的维度调色得到颜色值，我们这里就用360/1000 得到H，也就对应了RGB的颜色。而S和V是饱和度和明度，也就是颜色的鲜艳程度和亮暗程度。
//将大写字母转化成小写字母
int tolower(int c)
{
if(c >= 'A' && c <= 'Z')
{
return c + 'a' - 'A';
}
else
{
return c;
}
}
//将十六进制字符串转换成十进制整数
int htoi(char s[],char ucLentoStr)
{
int i,j;
int n = 0;
if (s == '0' && (s=='x' || s=='X'))
{
i = 2;
}
else
{
i = 0;
}
for (i=0;((s >= '0' && s <= '9') || (s >= 'a' && s <= 'z') || (s >='A' && s <= 'Z')) && i<ucLentoStr;i++)
{
if (tolower(s) > '9')
{
n = 16 * n + (10 + tolower(s) - 'a');
}
else
{
n = 16 * n + (tolower(s) - '0');
}
}
return n;
}
static void hsvSlipAdjust(unsigned char *ucHsvString,bool bIfSave)
{
float fRgbMin,fRgbMax,fRgbAdjust,s,v,r,g,b;
uint16_t usHsvEepromAddr,i,difs,h,eeprom_addr,usRgbMax,usRgbMin,usRgbAdjust;
char ucNum,ucHsv;
unsigned char ucEepromHsv = {0};
for(ucNum=0;ucNum<4;ucNum++)
{
CPwmCtrl.ucCh3HueStr = ucHsvString;
CPwmCtrl.ucCh3SaturationStr = ucHsvString;
CPwmCtrl.ucCh3ValueStr = ucHsvString;
}
CPwmCtrl.usCh3SaturationTarget = htoi(CPwmCtrl.ucCh3SaturationStr,4);
CPwmCtrl.usCh3ValueTarget = htoi(CPwmCtrl.ucCh3ValueStr,4);
CPwmCtrl.usCh3HueTarget = htoi(CPwmCtrl.ucCh3HueStr,4);
//HSV to RGB
#if 1
h = CPwmCtrl.usCh3HueTarget;
s = CPwmCtrl.usCh3SaturationTarget / 1000.0f;
v = CPwmCtrl.usCh3ValueTarget / 1000.0f;
if(h >= HUE_TOP_VALUE)
{
h = 0.0f;
}
if(s == 0.0f)
{
r = v;
g = v;
b = v;
}
else
{
fRgbMax = v;
fRgbMin = fRgbMax * (1.0f - s);
i = h / 60;
difs = h % 60;//factoraial part of H
fRgbAdjust = (fRgbMax - fRgbMin) * difs / 60.0f;// RGB adjustment amount by hue
switch(i)
{
case 0:
r = fRgbMax;
g = fRgbMin + fRgbAdjust;
b = fRgbMin;
break;
case 1:
r = fRgbMax - fRgbAdjust;
g = fRgbMax;
b = fRgbMin;
break;
case 2:
r = fRgbMin;
g = fRgbMax;
b = fRgbMin + fRgbAdjust;
break;
case 3:
r = fRgbMin;
g = fRgbMax - fRgbAdjust;
b = fRgbMax;
break;
case 4:
r = fRgbMin + fRgbAdjust;
g = fRgbMin;
b = fRgbMax;
break;
case 5:
r = fRgbMax;
g = fRgbMin;
b = fRgbMax - fRgbAdjust;
break;
default:
/*
r = fRgbMax;
g = fRgbMin;
b = fRgbMax - fRgbAdjust;
*/
break;
}
}
CPwmCtrl.usCh3RedTarget = (uint16_t)round(r * 255);
CPwmCtrl.usCh3GreenTarget = (uint16_t)round(g * 255);
CPwmCtrl.usCh3BlueTarget = (uint16_t)round(b * 255);
#else
fRgbMax = CPwmCtrl.usCh3ValueTarget * RGB_LIMIT / 1000.0f;
fRgbMin = fRgbMax * ((TIMER_ARR+1) - CPwmCtrl.usCh3SaturationTarget) / 1000.0f;
i = CPwmCtrl.usCh3HueTarget / 60;
difs = CPwmCtrl.usCh3HueTarget % 60;
fRgbAdjust = (usRgbMax - usRgbMin)*difs / 60.0f;
switch(i)
{
case 0:
CPwmCtrl.usCh3RedTarget = fRgbMax;
CPwmCtrl.usCh3GreenTarget = (fRgbMin + fRgbAdjust);
CPwmCtrl.usCh3BlueTarget = fRgbMin;
break;
case 1:
CPwmCtrl.usCh3RedTarget = (fRgbMax - fRgbAdjust);
CPwmCtrl.usCh3GreenTarget = fRgbMax;
CPwmCtrl.usCh3BlueTarget = fRgbMin;
break;
case 2:
CPwmCtrl.usCh3RedTarget = fRgbMin;
CPwmCtrl.usCh3GreenTarget = fRgbMax;
CPwmCtrl.usCh3BlueTarget = (fRgbMin + fRgbAdjust);
break;
case 3:
CPwmCtrl.usCh3RedTarget = fRgbMin;
CPwmCtrl.usCh3GreenTarget = (fRgbMax - fRgbAdjust);
CPwmCtrl.usCh3BlueTarget = fRgbMax / 1000.0f;
break;
case 4:
CPwmCtrl.usCh3RedTarget = (fRgbMin + fRgbAdjust);
CPwmCtrl.usCh3GreenTarget = fRgbMin;
CPwmCtrl.usCh3BlueTarget = fRgbMax;
break;
/*
case 5:
CPwmCtrl.usCh3RedTarget = fRgbMax;
CPwmCtrl.usCh3GreenTarget = fRgbMin;
CPwmCtrl.usCh3BlueTarget = (fRgbMax - fRgbAdjust);
break;
*/
default:
CPwmCtrl.usCh3RedTarget = fRgbMax;
CPwmCtrl.usCh3GreenTarget = fRgbMin;
CPwmCtrl.usCh3BlueTarget = (fRgbMax - fRgbAdjust);
break;
}
/*
if(r > 1000)
{
r = 1000;
}
if(g > 1000)
{
g = 1000;
}
if(b > 1000)
{
b = 1000;
}
*/
#endif
/*
CPwmCtrl.ucCh3RedTarget = (uint16_t)round(r * 255000);///(uint16_t)(r * (TIMER_ARR + 1) / 255);///(uint16_t)round(r * 25500);
CPwmCtrl.ucCh3GreenTarget = (uint16_t)round(g * 255000);///(uint16_t)(g * (TIMER_ARR + 1) / 255);///(uint16_t)round(g * 25500);
CPwmCtrl.ucCh3BlueTarget = (uint16_t)round(b * 255000);///(uint16_t)(b * (TIMER_ARR + 1) / 255);///(uint16_t)round(b * 25500);
*/
pwm_SetPulseWidth(CPwmCtrl.usCh3RedTarget,CH2_RED);
__asm("nop");
pwm_SetPulseWidth(CPwmCtrl.usCh3GreenTarget,CH2_GREEN);
__asm("nop");
pwm_SetPulseWidth(CPwmCtrl.usCh3BlueTarget,CH2_BLUE);
__asm("nop");
if(bIfSave)
{
ucEepromHsv = (uint8_t)(CPwmCtrl.usCh3HueTarget >> 8);
ucEepromHsv = (uint8_t)CPwmCtrl.usCh3HueTarget;
ucEepromHsv = (uint8_t)(CPwmCtrl.usCh3SaturationTarget >> 8);
ucEepromHsv = (uint8_t)CPwmCtrl.usCh3SaturationTarget;
ucEepromHsv = (uint8_t)(CPwmCtrl.usCh3ValueTarget >> 8);
ucEepromHsv = (uint8_t)(CPwmCtrl.usCh3ValueTarget);
__asm("nop");
CAppFlash.WriteBytes(FLASH_PROGRAM_ADDRESS_START,0x06,ucEepromHsv,6);
}
}
因为涂鸦的协议是用字符串下发HSV的值，例如"023401320128"，H=0x0234,S=0x0132,V=0x0128,所以这里先要把字符串转换成十六进制，每次转换4个字符，所以调用htoi函数字符串的每次转换长度为4。这里设置pwm通道的值也可以直接用TIM->CCR寄存器。
根据公式，每60°一个等分，也就是把360° 6等分，然后根据颜色值在圆上的区域，结合代码理解，每一个case是由H进行选择，
fRgbMax = v; fRgbMin = fRgbMax * (1.0f - s);
i = h / 60;
difs = h % 60;//factoraial part of H
fRgbAdjust = (fRgbMax - fRgbMin) * difs / 60.0f;// RGB adjustment amount by hue 把S和V代入计算可知，max的值始终大于min的值，当S最大且V最小或者是S最小V最大，fRgbAdjust的值都为0，这样S和V就可以体现出颜色的饱和度和明度了。
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