/**
 * @packageDocumentation
 * @module Parts.HC-SR04
 */
import Obniz from '../../../obniz';
import { PeripheralIO } from '../../../obniz/libs/io_peripherals/io';
import { ObnizPartsInterface, ObnizPartsInfo } from '../../../obniz/ObnizPartsInterface';
export interface HCSR04Options {
    gnd?: number;
    echo: number;
    trigger: number;
    vcc: number;
}
export declare type HCSR04UnitType = 'mm' | 'inch';
export default class HCSR04 implements ObnizPartsInterface {
    static info(): ObnizPartsInfo;
    keys: string[];
    requiredKeys: string[];
    _unit: HCSR04UnitType;
    reset_alltime: boolean;
    temp: number;
    obniz: Obniz;
    params: any;
    vccIO: PeripheralIO;
    trigger: number;
    echo: number;
    constructor();
    wired(obniz: Obniz): void;
    measure(callback: (distance: number) => void): void;
    measureWait(): Promise<number>;
    unit(unit: HCSR04UnitType): void;
}