日志
pca9685模塊
熱度 1
/**************************************************************************
PCA9685模塊簡單應(yīng)用
平臺：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度對應(yīng)4096的脈寬計數(shù)值
#define SERVO180 520 //180度對應(yīng)4096的脈寬計算值，四個值可根據(jù)不同舵機(jī)修改
/**********************函數(shù)的聲明*********************************/
/*---------------------------------------------------------------
毫秒延時函數(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)
----------------------------------------------------------------*/
/*---------------------------------------------------------------
微妙級別延時函數(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總線啟動信號函數(shù)
----------------------------------------------------------------*/
void start()
{
sda=1;
delayus();
scl=1; //scl拉高時 sda突然來個低電平 就啟動了IIC總線
delayus();
sda=0;
delayus();
scl=0;
delayus();
}
/*---------------------------------------------------------------
IIC總線停止信號函數(shù)
----------------------------------------------------------------*/
void stop()
{
sda=0;
delayus();
scl=1; //scl拉高時 sda突然來個高電平 就停止了IIC總線
delayus();
sda=1;
delayus();
}
/*---------------------------------------------------------------
IIC總線應(yīng)答信號函數(shù)
----------------------------------------------------------------*/
void ACK()
{
uchar i;
scl=1;
delayus();
while((sda=1)&&(i<255))
i++;
scl=0;
delayus();
}
/*---------------------------------------------------------------
寫一個字節(jié),無返回值，需輸入一個字節(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上升計數(shù)值0~4096,off:PWM下降計數(shù)值0~4096
一個PWM周期分成4096份，由0開始+1計數(shù)，計到on時跳變?yōu)楦唠娖�，繼續(xù)計數(shù)到off時
跳變?yōu)榈碗娖�，直到計滿4096重新開始。所以當(dāng)on不等于0時可作延時,當(dāng)on等于0時，
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對應(yīng)周期20ms
//setPWM(num,0,239);;;;當(dāng)然也可以利用SERVO000和SERVO180計算
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);
}
}
