利用MSP430F149控制LED燈的電流恒定

1、利用MSP430F149控制LED燈的電流恒定硬件部分升壓斬波電路（Boost Chopper）的基本原理負(fù)載為L(zhǎng)ED燈電路圖當(dāng)可控開(kāi)關(guān)IGBT處于通態(tài)時(shí)，時(shí)間為，電源向電感L充電，充電電流基本恒定為，同時(shí)電容C的電壓向負(fù)載R供電。因C值很大，基本保持輸出電壓。為恒值，L上積累的能量為。當(dāng)IGBT處于斷態(tài)時(shí)，時(shí)間為，E和L共同向電容C充電并向R提供能量，此期間電感L釋放的能量為。當(dāng)電路工作處于穩(wěn)態(tài)時(shí)，一個(gè)周期中電感L積蓄和釋放的能量相等，即=化簡(jiǎn)得 設(shè)計(jì)思路編程讓430單片機(jī)產(chǎn)生占空比可調(diào)的PWM方波，通過(guò)占空比的調(diào)節(jié)來(lái)控制MOS管的開(kāi)啟時(shí)間，從而調(diào)節(jié)電路的電流，達(dá)到相對(duì)恒定的電流。通過(guò)單片機(jī)

2、內(nèi)部的AD轉(zhuǎn)換模塊，采集到硬件電路的電壓值，比較得出電壓（或電流）的變化趨勢(shì)（增大還是減?。?，若電壓（電流）增大，則減小占空比，縮短MOS管的開(kāi)啟時(shí)間；反之，增大占空比，增加MOS管的開(kāi)啟時(shí)間。本程序利用定時(shí)器A產(chǎn)生PWM方波。軟件部分主要代碼主函數(shù)文件名*main.c*#include #include cry1602.h#include cry1602.c#include pwm.ctypedef unsigned char uchar;typedef unsigned int uint;#define Num_of_Results 32#define M 1000uchar shuzi

3、= 0123456789.;uchar tishi = The volt is:;static uint resultsNum_of_Results; /保存ADC轉(zhuǎn)換結(jié)果的數(shù)組 / is not used for anything.void Trans_val(uint Hex_Val); void main(void) /主函數(shù) WDTCTL = WDTPW+WDTHOLD; /關(guān)閉看門(mén)狗 /下面六行程序關(guān)閉所有的IO口 P1DIR = 0XFF;P1OUT = 0XFF; P2DIR = 0XFF;P2OUT = 0XFF; P3DIR = 0XFF;P3OUT = 0XFF; P4DI

4、R = 0XFF;P4OUT = 0XFF; P5DIR = 0XFF;P5OUT = 0XFF; P6DIR = 0XFF;P6OUT = 0XFF; /初始化 P6DIR |= BIT2;P6OUT |= BIT2; /關(guān)閉電平轉(zhuǎn)換 P5DIR|=BIT5;P5OUT&=BIT5; /關(guān)閉數(shù)碼管顯示 P6DIR|=BIT6;P6OUT&=BIT6; /半閉數(shù)碼管顯示 P6DIR|=BIT5;P6OUT&=BIT5; /半閉數(shù)碼管顯示 /LCD設(shè)置 LcdReset(); /復(fù)位1602液晶 DispNChar(2,0,12,tishi); /顯示提示信息 Disp1Char(11,1,V)

5、; /顯示電壓?jiǎn)挝?/ADC設(shè)置 P6SEL |= 0 x01; / 使能ADC通道 ADC12CTL0 = ADC12ON+SHT0_8+MSC; / 打開(kāi)ADC，設(shè)置采樣時(shí)間 ADC12CTL1 = SHP+CONSEQ_2; / 使用采樣定時(shí)器 ADC12IE = 0 x01; / 使能ADC中斷 ADC12CTL0 |= ENC; / 使能轉(zhuǎn)換 ADC12CTL0 |= ADC12SC; / 開(kāi)始轉(zhuǎn)換 _EINT(); LPM0;/ADC中斷服務(wù)函數(shù)/多次平均計(jì)算P6.0口的模擬電壓數(shù)值/調(diào)節(jié)占空比 #pragma vector=ADC_VECTOR_interrupt void AD

6、C12ISR (void) static uint index = 0; uint result; result = ADC12MEM0; resultsindex+ = ADC12MEM0; / Move results if(index = Num_of_Results) uchar i; unsigned long sum = 0; index = 0; for(i = 0; i = 5; /除以32 Trans_val(sum); if(result M ) if(result - M) 980) TACCR1 = 32; else if(result - M) 650) TACCR1

7、 = 40; else if(result - M) 320) TACCR1 = 50; else if(result - M) 0) TACCR1 = 60; else if( M - result ) 380) TACCR1 = 50; else if(M - result) 490) TACCR1 = 60; else TACCR1 = 70; out_pwm();/將16進(jìn)制ADC轉(zhuǎn)換數(shù)據(jù)變換成三位10進(jìn)制/真實(shí)的模擬電壓數(shù)據(jù)，并在液晶上顯示void Trans_val(uint Hex_Val) unsigned long caltmp; uint Curr_Volt; uchar

8、t1,i; uchar ptr4; caltmp = Hex_Val; caltmp = (caltmp 5) + Hex_Val; /caltmp = Hex_Val * 33 caltmp = (caltmp 3) + (caltmp 12; /Curr_Volt = caltmp / 2n ptr0 = Curr_Volt / 100; /Hex-Dec變換 t1 = Curr_Volt - (ptr0 * 100); ptr2 = t1 / 10; ptr3 = t1 - (ptr2 * 10); ptr1 = 10; /shuzi表中第10位對(duì)應(yīng)符號(hào). /在液晶上顯示變換后的結(jié)果 f

9、or(i = 0;i 4;i+) Disp1Char(6 + i),1,shuziptri);PWM輸出模塊用定時(shí)器A輸出pwm信號(hào),1.2作為輸出文件名*pwm.c*#include void out_pwm() /輸出pwm信號(hào) uchar i; BCSCTL1 &= XT2OFF; /打開(kāi)XT振蕩器 BCSCTL2 |= SELM_2+SELS; /MCLK為8MHz,SMCLK為8MHz do IFG1 &= OFIFG; /清除振蕩錯(cuò)誤標(biāo)志 for(i = 0; i 100;i +) /延時(shí)等待 _NOP(); while(IFG1 & OFIFG) != 0); /如果標(biāo)志為1,則繼續(xù)循環(huán)等待 IFG1 &= OFIFG;