const i2cBus = require("i2c-bus")
const { Pca9685Driver } = require("pca9685")

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");
            }
        })
        console.log('测试开始');
        // test
        let a = 128
        setInterval(() => {
            this.PWM.setPulseLength(3, this.Servo2pwm(a));                  
            console.log(a);
        }, 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()