pikojs/src/index.js

Nodejs package to retrieve PV data from a Piko Kostal Inverter.

/* 
 * pikojs
 *
 * Copyright (c) 2018 pitfermi (Petros Mavridis). 
 *
 * pikojs's license follows:
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without restriction,
 * including without limitation the rights to use, copy, modify, merge, 
 * publish, distribute, sublicense, and/or sell copies of the Software, 
 * and to permit persons to whom the Software is furnished to do so, 
 * subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS 
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 * 
 * This license applies to all parts of pikojs that are not externally
 * maintained libraries.
 */

var axios = require('axios');
var cheerio = require('cheerio');

/**
 * Initialize Piko object
 * @param {object} options 
 * @return {void}
 */
function Piko(options) {
    this._options = {
        host: options.hostname || null,
        username: options.username || 'pvserver',
        password: options.password || 'pvwr',
        port: options.port || '80'
    };
}

/**
 * Fetch HTML from the Piko webpage using Promises.
 * Note that getData returns a Promise
 * @return {Promise<object>}
 */
Piko.prototype.getData = async function () {
    try {
        const url = `${this._options.host}:${this._options.port}`;

        return this.parseHTML(
            (await axios(url, {
                method: 'get',
                auth: {
                    username: this._options.username,
                    password: this._options.password
                }
            })).data
        );
    } catch (error) {
        console.log(error);
    }
};

/**
 * Parse the HTML for the various values 
 * using CSS selectors
 * @param {string} htmlPage htmlpage string to be parsed
 * @return {object}        
 */
Piko.prototype.parseHTML = function (htmlPage) {

    var $ = cheerio.load(htmlPage);

    let name = $('body > form > table > tr:nth-child(2) > td:nth-child(2) > font > font').text().trim();

    let currentACPower = this.fixValue($('body > form > font > table:nth-child(2) > tr:nth-child(4) > td:nth-child(3)').text());
    let dailyEnergy = this.fixValue($('body > form > font > table:nth-child(2) > tr:nth-child(6) > td:nth-child(6)').text());
    let totalEnergy = this.fixValue($('body > form > font > table:nth-child(2) > tr:nth-child(4) > td:nth-child(6)').text());

    let status = $('body > form > font > table:nth-child(2) > tr:nth-child(8) > td:nth-child(3)').text().trim();

    let dcV1 = this.fixValue($('body > form > tr:nth-child(7) > td:nth-child(3)').text());
    let dcC1 = this.fixValue($('body > form > tr:nth-child(9) > td:nth-child(3)').text());
    let dcV2 = this.fixValue($('body > form > tr:nth-child(12) > td:nth-child(3)').text());
    let dcC2 = this.fixValue($('body > form > tr:nth-child(14) > td:nth-child(3)').text());
    let dcV3 = this.fixValue($('body > form > tr:nth-child(17) > td:nth-child(3)').text());
    let dcC3 = this.fixValue($('body > form > tr:nth-child(19) > td:nth-child(3)').text());

    let acV1 = this.fixValue($('body > form > tr:nth-child(7) > td:nth-child(6)').text());
    let acP1 = this.fixValue($('body > form > tr:nth-child(9) > td:nth-child(6)').text());
    let acV2 = this.fixValue($('body > form > tr:nth-child(12) > td:nth-child(6)').text());
    let acP2 = this.fixValue($('body > form > tr:nth-child(14) > td:nth-child(6)').text());
    let acV3 = this.fixValue($('body > form > tr:nth-child(17) > td:nth-child(6)').text());
    let acP3 = this.fixValue($('body > form > tr:nth-child(19) > td:nth-child(6)').text());


    return {
        name,
        status,
        currentACPower,
        dailyEnergy,
        totalEnergy,
        units: {
            power: "W",
            energy: "kWh",
            voltage: "V",
            current: "A"
        },
        dc: [
            {
                id: "1",
                voltage: dcV1,
                current: dcC1
            },
            {
                id: "2",
                voltage: dcV2,
                current: dcC2
            },
            {
                id: "3",
                voltage: dcV3,
                current: dcC3
            }
        ],
        ac: [
            {
                id: "1",
                voltage: acV1,
                power: acP1
            },
            {
                id: "2",
                voltage: acV2,
                power: acP2
            },
            {
                id: "3",
                voltage: acV3,
                power: acP3
            }
        ]
    };
}

/**
 * Fix value in case '0' is represented as 'x x x...'
 * @param {string} value
 * @return {number}
 */
Piko.prototype.fixValue = function (value) {
    if (typeof value === 'string') {
        value = value.trim();
    }
    return (value.includes("x x x") ? 0 : parseFloat(value));
}

module.exports = Piko;