sensor/GetStopBit.js

const i2cBus = require("i2c-bus")
const { Pca9685Driver } = require("pca9685")
const RPIO = require("rpio");
const sleep = (ms) => new Promise((resolve) => setTimeout(resolve, ms))
class ContrlService {
    constructor() {
        // PWM 和 舵机配置
        this.pwmOption = {
            i2c: i2cBus.openSync(1), // 树莓派1：scl1
            address: 0x40, //板子地址
            frequency: 50, //频率
            debug: false
        }

        // init PWM
        this.PWM = new Pca9685Driver(this.pwmOption, er => {
            if (er) {
                console.error("Error initializing PCA9685");
            }
        })

        // prio init
        RPIO.init({ mapping: "gpio" });

        // init PWM
        this.ins = 0
        this.timer = 0

        // test Pwm
        this.num = 0
        this.startInt()
    }

    // 测试全程找中位
    startInt() {
        console.log('start');
        RPIO.open(6, RPIO.OUTPUT, RPIO.HIGH);
        RPIO.open(13, RPIO.OUTPUT, RPIO.HIGH);
        RPIO.open(19, RPIO.OUTPUT, RPIO.HIGH);
        this.timer = setInterval(() => {
            this.num++
            // if (this.num >= 255) {
            //     // 继电器停止
            //     RPIO.open(6, RPIO.OUTPUT, RPIO.LOW);
            //     RPIO.open(13, RPIO.OUTPUT, RPIO.LOW);
            //     RPIO.open(19, RPIO.OUTPUT, RPIO.LOW);
            //     clearInterval(this.timer);
            //     this.num = 0
            //     console.log('end');
            //     return
            // }
            // 寻找中位=>120-130
            if(this.num >= 120 && this.num <= 130){
                this.PWM.setPulseLength(this.ins, this.Servo2pwm(this.num));
                clearInterval(this.timer);
                console.log('center',this.num);
                return
            }
            this.PWM.setPulseLength(this.ins, this.Servo2pwm(10));
            console.log(this.num);
        }, 50);
    }

    /**
     * 舵机换算比例：摇杆范围0-256，PWM范围1000~1500~2000
     * @param {number} v 
     * @returns 
     */
    Servo2pwm(v) {
        return parseInt(v / (256 / 1000)) + 1000
    }
}
new ContrlService()