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51控制PCA9685,使用软件模拟IIC,都在代码里了。
目的是为了控制16X舵机,50HZ
单片机源程序如下:
- /* PCA9685驱动程序 */
- /* 使用IO口模拟通信 */
- /* 16路PWM输出 */
- #include<reg52.h>
- #include<intrins.h>
- sbit SCL=P1^0; //定义时钟引脚
- sbit SDA=P1^1; //定义数据引脚
- #define PCA9685_adrr 0x80//1+A5+A4+A3+A2+A1+A0+w/r
- #define PCA9685_SUBADR1 0x2
- #define PCA9685_SUBADR2 0x3
- #define PCA9685_SUBADR3 0x4
- #define PCA9685_MODE1 0x0
- #define PCA9685_MODE2 0x1
- #define PCA9685_PRESCALE 0xFE
- #define pwm0_ON_L 0x6
- #define pwm0_ON_H 0x7
- #define pwm0_OFF_L 0x8
- #define pwm0_OFF_H 0x9
- #define ALLpwm_ON_L 0xFA
- #define ALLpwm_ON_H 0xFB
- #define ALLpwm_OFF_L 0xFC
- #define ALLpwm_OFF_H 0xFD
- void iic_delay()//延时5us
- {
- _nop_();
- _nop_();
- _nop_();
- _nop_();
- _nop_();
- }
- void iic_start()//scl高电平区间,sda一个下降沿启动信号
- {
- SDA=1;
- iic_delay();
- SCL=1;
- iic_delay();
- SDA=0;
- iic_delay();
- SCL=0;
- iic_delay();
- }
- void iic_stop()//scl在高电平区间,sda一个上升沿信号
- {
- SDA=0;
- iic_delay();
- SCL=1;
- iic_delay();
- SDA=1;
- iic_delay();
- }
- void iic_wait_ack()//在scl高位时,从机拉低sda引脚表示应答
- {
- unsigned char i=0;
- SCL=1;
- iic_delay();
- while((SDA==1)&&(i<255))
- {
- i++;
- }
- SCL=0;
- iic_delay();
- }
- void iic_init()//初始化IIC通讯引脚
- {
- SCL=1;
- iic_delay();
- SDA=1;
- iic_delay();
- }
- void iic_send_ack(bit iic_ack)//接受完成之后,发送应答位,0应答继续发送,1不应答停止发送
- {
- SDA=iic_ack;
- SCL=1;
- iic_delay();
- SCL=0;
- iic_delay();
- }
- void iic_write_byte(unsigned char iic_byte)
- {
- unsigned char i=0;
- for(i=0;i<8;i++)
- {
- SCL=0;
- iic_delay();
- SDA=iic_byte&0X80;
- iic_byte=iic_byte<<1;
- iic_delay();
- SCL=1;
- iic_delay();
- }
- SCL=0;
- iic_delay();
- SDA=1;
- iic_wait_ack();
- }
- void iic_write(unsigned char slave_addr,unsigned char iic_addr,unsigned char iic_byte)
- {
- iic_init();
- iic_start();
- iic_write_byte(slave_addr);
- iic_write_byte(iic_addr);
- iic_write_byte(iic_byte);
- iic_stop();
- }
- unsigned char iic_read_byte()//读字节,先读高位,左移
- {
- unsigned char i=0;
- unsigned char iic_byte=0;
- SCL=0;
- iic_delay();
- SDA=1; //确保主机释放SDA
- iic_delay();
- for(;i<8;i++)
- {
- iic_delay();
- SCL=1;
- iic_delay();
- iic_byte=(iic_byte<<1)|SDA;
- SCL=0;
- }
- iic_delay();
- return iic_byte;
- }
- unsigned char iic_read(unsigned char slave_addr,unsigned char iic_addr)
- {
- unsigned char iic_byte;
- iic_init();
- iic_start();
- iic_write_byte(slave_addr);
- iic_write_byte(iic_addr);
- iic_start();
- iic_write_byte(slave_addr|0x01);//发送设备地址+读信号
- iic_byte=iic_read_byte();
- iic_send_ack(1);//发送非应答信号
- iic_stop();
- return iic_byte;
- }
- void pca_set_freq()//频率设置为50hz(20ms)
- {
- unsigned char prescale=132,oldmode,newmode;
- iic_write(0x80,0x00,0x0);
- oldmode=iic_read(0x80,0x00);
- newmode=(oldmode&0x7F)|0x10;
- iic_write(0x80,0x00,newmode);//进入sleep
- //设置频率时pca9685应该进入睡眠状态
- iic_write(0x80,0xFE,prescale);
- iic_write(0x80,0x00,oldmode);//退出sleep
- iic_write(0x80,0x00,oldmode|0xA1);//立即重启
- }
- void pca_set_pwm(unsigned char channel,unsigned char angle)
- {
- unsigned int off=102+(angle*2.27);
- iic_write(0x80,0x06+4*channel,0);
- iic_write(0x80,0x07+4*channel,0);
- iic_write(0x80,0x08+4*channel,off);
- iic_write(0x80,0x09+4*channel,off>>8);
- }
- void delay(unsigned char delay_a) //@11.0592MHz
- {
- while(delay_a)
- {
- unsigned char delay_b=255;
- while(delay_b)
- {
- iic_delay();
- iic_delay();
- delay_b--;
- }
- delay_a--;
- }
- }
- int main()
- {
- pca_set_freq();
- delay(155);
- pca_set_pwm(0,40);
- pca_set_pwm(1,40);
- delay(155);
- pca_set_pwm(0,140);
- pca_set_pwm(1,140);
- delay(155);
- pca_set_pwm(1,150);
- delay(155);
- pca_set_pwm(1,47);
- delay(155);
- pca_set_pwm(0,70);
- while(1);
- }
复制代码
51_pca9685_iic.rar
(1.33 KB, 下载次数: 63)
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