|
- /**************************************************************************
- PCA9685模塊簡(jiǎn)單應(yīng)用
- 平臺(tái):89C52,晶振:11.0592
- ***************************************************************************/
- #include<reg52.h>
- #include <intrins.h>
- #include <stdio.h>
- #include <math.h>
- typedef unsigned char uchar;
- typedef unsigned int uint;
- sbit scl=P3^6; //時(shí)鐘輸入線
- sbit sda=P3^7; //數(shù)據(jù)輸入/輸出端
- #define PCA9685_adrr 0x80// 1+A5+A4+A3+A2+A1+A0+w/r
- //片選地址,將焊接點(diǎn)置1可改變地址,
- // 當(dāng)IIC總 呱嫌 多片PCA9685或相同地址時(shí)才需焊接
- #define PCA9685_SUBADR1 0x2
- #define PCA9685_SUBADR2 0x3
- #define PCA9685_SUBADR3 0x4
- #define PCA9685_MODE1 0x0
- #define PCA9685_PRESCALE 0xFE
- #define LED0_ON_L 0x6
- #define LED0_ON_H 0x7
- #define LED0_OFF_L 0x8
- #define LED0_OFF_H 0x9
- #define ALLLED_ON_L 0xFA
- #define ALLLED_ON_H 0xFB
- #define ALLLED_OFF_L 0xFC
- #define ALLLED_OFF_H 0xFD
- #define SERVOMIN 115 // this is the 'minimum' pulse length count (out of 4096)
- #define SERVOMAX 590 // this is the 'maximum' pulse length count (out of 4096)
- #define SERVO000 130 //0度對(duì)應(yīng)4096的脈寬計(jì)數(shù)值
- #define SERVO180 520 //180度對(duì)應(yīng)4096的脈寬計(jì)算值,四個(gè)值可根據(jù)不同舵機(jī)修改
- /**********************函數(shù)的聲明*********************************/
- /*---------------------------------------------------------------
- 毫秒延時(shí)函數(shù)
- ----------------------------------------------------------------*/
- void delayms(uint z)
- {
- uint x,y;
- for(x=z;x>0;x--)
- for(y=148;y>0;y--);
- }
- /*---------------------------------------------------------------
- IIC總線所需的通用函數(shù)
- ----------------------------------------------------------------*/
- /*---------------------------------------------------------------
- 微妙級(jí)別延時(shí)函數(shù) 大于4.7us
- ----------------------------------------------------------------*/
- void delayus()
- {
- _nop_(); //在intrins.h文件里
- _nop_();
- _nop_();
- _nop_();
- _nop_();
- }
- /*---------------------------------------------------------------
- IIC總線初始化函數(shù)
- ----------------------------------------------------------------*/
- void init()
- {
- sda=1; //sda scl使用前總是被拉高
- delayus();
- scl=1;
- delayus();
- }
- /*---------------------------------------------------------------
- IIC總線啟動(dòng)信號(hào)函數(shù)
- ----------------------------------------------------------------*/
- void start()
- {
- sda=1;
- delayus();
- scl=1; //scl拉高時(shí) sda突然來(lái)個(gè)低電平 就啟動(dòng)了IIC總線
- delayus();
- sda=0;
- delayus();
- scl=0;
- delayus();
- }
- /*---------------------------------------------------------------
- IIC總線停止信號(hào)函數(shù)
- ----------------------------------------------------------------*/
- void stop()
- {
- sda=0;
- delayus();
- scl=1; //scl拉高時(shí) sda突然來(lái)個(gè)高電平 就停止了IIC總線
- delayus();
- sda=1;
- delayus();
- }
- /*---------------------------------------------------------------
- IIC總線應(yīng)答信號(hào)函數(shù)
- ----------------------------------------------------------------*/
- void ACK()
- {
- uchar i;
- scl=1;
- delayus();
- while((sda=1)&&(i<255))
- i++;
- scl=0;
- delayus();
- }
- /*---------------------------------------------------------------
- 寫一個(gè)字節(jié),無(wú)返回值,需輸入一個(gè)字節(jié)值
- ----------------------------------------------------------------*/
- void write_byte(uchar byte)
- {
- uchar i,temp;
- temp=byte;
- for(i=0;i<8;i++)
- {
- temp=temp<<1;
- scl=0;
- delayus();
- sda=CY;
- delayus();
- scl=1;
- delayus();
- }
- scl=0;
- delayus();
- sda=1;
- delayus();
- }
- /*---------------------------------------------------------------
- 讀一個(gè)字節(jié)函數(shù),有返回值
- ----------------------------------------------------------------*/
- uchar read_byte()
- {
- uchar i,j,k;
- scl=0;
- delayus();
- sda=1;
- delayus();
- for(i=0;i<8;i++)
- {
- delayus();
- scl=1;
- delayus();
- if(sda==1)
- {
- j=1;
- }
- else j=0;
- k=(k<< 1)|j;
- scl=0;
- }
- delayus();
- return k;
- }
- /*---------------------------------------------------------------
- 有關(guān)PCA9685模塊的函數(shù)
- ----------------------------------------------------------------*/
- /*---------------------------------------------------------------
- 向PCA9685里寫地址,數(shù)據(jù)
- ----------------------------------------------------------------*/
- void PCA9685_write(uchar address,uchar date)
- {
- start();
- write_byte(PCA9685_adrr); //PCA9685的片選地址
- ACK();
- write_byte(address); //寫地址控制字節(jié)
- ACK();
- write_byte(date); //寫數(shù)據(jù)
- ACK();
- stop();
- }
- /*---------------------------------------------------------------
- 從PCA9685里的地址值中讀數(shù)據(jù)(有返回值)
- ----------------------------------------------------------------*/
- uchar PCA9685_read(uchar address)
- {
- uchar date;
- start();
- write_byte(PCA9685_adrr); //PCA9685的片選地址
- ACK();
- write_byte(address);
- ACK();
- start();
- write_byte(PCA9685_adrr|0x01); //地址的第八位控制數(shù)據(jù)流方向,就是寫或讀
- ACK();
- date=read_byte();
- stop();
- return date;
- }
- /*---------------------------------------------------------------
- PCA9685復(fù)位
- ----------------------------------------------------------------*/
- void reset(void)
- {
- PCA9685_write(PCA9685_MODE1,0x0);
- }
- void begin(void)
- {
- reset();
- }
- /*---------------------------------------------------------------
- PCA9685修改頻率函數(shù)
- ----------------------------------------------------------------*/
- void setPWMFreq(float freq)
- {
- uint prescale,oldmode,newmode;
- float prescaleval;
- freq *= 0.92; // Correct for overshoot in the frequency setting
- prescaleval = 25000000;
- prescaleval /= 4096;
- prescaleval /= freq;
- prescaleval -= 1;
- prescale = floor(prescaleval + 0.5);
- oldmode = PCA9685_read(PCA9685_MODE1);
- newmode = (oldmode&0x7F) | 0x10; // sleep
- PCA9685_write(PCA9685_MODE1, newmode); // go to sleep
- PCA9685_write(PCA9685_PRESCALE, prescale); // set the prescaler
- PCA9685_write(PCA9685_MODE1, oldmode);
- delayms(2);
- PCA9685_write(PCA9685_MODE1, oldmode | 0xa1);
- }
- /*---------------------------------------------------------------
- PCA9685修改角度函數(shù)
- num:舵機(jī)PWM輸出引腳0~15,on:PWM上升計(jì)數(shù)值0~4096,off:PWM下降計(jì)數(shù)值0~4096
- 一個(gè)PWM周期分成4096份,由0開(kāi)始+1計(jì)數(shù),計(jì)到on時(shí)跳變?yōu)楦唠娖剑^續(xù)計(jì)數(shù)到off時(shí)
- 跳變?yōu)榈碗娖剑钡接?jì)滿4096重新開(kāi)始。所以當(dāng)on不等于0時(shí)可作延時(shí),當(dāng)on等于0時(shí),
- off/4096的值就是PWM的占空比。
- ----------------------------------------------------------------*/
- void setPWM(uint num, uint on, uint off)
- {
- PCA9685_write(LED0_ON_L+4*num,on);
- PCA9685_write(LED0_ON_H+4*num,on>>8);
- PCA9685_write(LED0_OFF_L+4*num,off);
- PCA9685_write(LED0_OFF_H+4*num,off>>8);
- }
- /*---------------------------------------------------------------
- 主函數(shù)
- ----------------------------------------------------------------*/
- void main()
- {
- begin();
- setPWMFreq(50);
- //例如要求舵機(jī)轉(zhuǎn)到60度,這么算,
- //60度對(duì)應(yīng)的脈寬=0.5ms+(60/180)*(2.5ms-0.5ms)=1.1666ms
- //利用占空比=1.1666ms/20ms=off/4096,off=239,50hz對(duì)應(yīng)周期20ms
- //setPWM(num,0,239);;;;當(dāng)然也可以利用SERVO000和SERVO180計(jì)算
- while(1)
- {
- setPWM(0, 0, SERVOMIN);//第0路舵機(jī)轉(zhuǎn)到最小角度
- setPWM(1, 0, SERVO000);//第1路舵機(jī)轉(zhuǎn)到0角度
- setPWM(15, 0, 3000);
- delayms(1500);
- // setPWM(0, 0, SERVOMAX);
- // setPWM(1, 0, SERVO180);
- // delayms(1500);
- }
- }
復(fù)制代碼
|
|