電子ボリュームの減衰値を計算するJavaScript

potic-solver.js

//
// 電子ボリュームの減衰値を計算するJavaScript
// http://ak1211.com
// Copyright (c) 2018 Akihiro Yamamoto
//
//
// This software is released under the MIT License.
// http://opensource.org/licenses/mit-license.php
//

// 1次関数 y = ax+b
const linearFn = (arr, a, b) => {
    const dy = a/(arr.length-1);
    let y = b;
    for (let i=0; i<arr.length; i++) {
        arr[i] = y;
        y += dy;
    }
    return arr;
};

// logarithmic pot taper
const logPotTaper = (arr, valOfX05) => {
    const a = Math.log( valOfX05 ) / (0.5 - 1);
    const f = p => Math.exp( a*(p-1) );
    for (let i=0; i<arr.length; i++) {
        arr[i] = f(i/100) ;
    }
    return arr;
}

// potentiometer taper graph
nv.addGraph( () => {
    const chart = nv.models.lineChart()
                    .useInteractiveGuideline(true)
                    .showLegend(true)
                    .showXAxis(true)
                    .showYAxis(true)
                    ;

    chart.xAxis
        .axisLabel('Position (%)');
    chart.yAxis
        .axisLabel('Output voltage  / Input voltage (%)')
        .tickFormat(d3.format(',.2f'));

    d3.select('#pot-taper')
        .append('svg')
        .attr('width', 320)
        .attr('height', 320)
        .datum( [{
                color:'deepskyblue',
                key:'10%',
                values: logPotTaper( new Array(101), 0.10 )
                        .map( (y,i) => ({x: i, y: y*100.0}) )
                },
                {
                color:'green',
                key:'15%',
                values: logPotTaper( new Array(101), 0.15 )
                        .map( (y,i) => ({x: i, y: y*100.0}) )
                },
                {
                color:'slateblue',
                key:'20%',
                values: logPotTaper( new Array(101), 0.20 )
                        .map( (y,i) => ({x: i, y: y*100.0}) )
                }])
        .transition()
        .duration(500)
        .call(chart);

    nv.utils.windowResize(chart.update);
    return chart;
});

// pivot が log側にいるか確かめる
const isLogarithmicSide = pivot => {
    const f = x => x;  // 関数 y=x
    return (f(pivot.x) > pivot.y);
};

// pivot より100%に近い側の直線
// pivot.x = 1 の値は定義されない
const upperLine = (arr, pivot) => {
    const grad = (1.0 - pivot.y) / (1.0 - pivot.x);
    return linearFn( arr, grad, pivot.y - grad*pivot.x );
};

// pivot より0%に近い側の直線
// pivot.x = 0 の値は定義されない
const lowerLine = (arr, pivot) => {
    const grad = pivot.y / pivot.x;
    return linearFn( arr, grad, 0.0 );
};

//
const bendLineWithPivot = (arr, pivot) => {
    const lo = lowerLine( new Array(arr.length), pivot );
    const up = upperLine( new Array(arr.length), pivot );
    const fn = isLogarithmicSide(pivot) ? Math.max : Math.min;
    for (let i=0; i<arr.length; i++) {
        arr[i] = fn( lo[i], up[i] );
    }
    return arr;
};

//
const customTaper = (pivot, bias, linerPotTaper) => {
    const c = bendLineWithPivot( new Array(linerPotTaper.length), pivot );
    const isLineLogSide = (bias < 0);
    // 屈折点と直線成分が同一領域にいる場合にのみ合成する
    if( isLogarithmicSide(pivot) == isLineLogSide ) {
        const fn = isLogarithmicSide(pivot) ? Math.max : Math.min;
        return c.map( (_,i,y) => fn( y[i], linerPotTaper[i] ) );
    } else {
        // 直線成分を無視する
        return c;
    }
};
const readUserInputs = () => {
    return {
        pivot: {x: d3.select('#taperPivotX').property('value'),
                y: d3.select('#taperPivotY').property('value')},
        bias: 1.0 - d3.select('#linerBias').property('value'),
        steps: d3.select('#volSteps').property('value'),
    };
};


// custom potentiometer taper data
const customPotTaper = () => {
    const pivot = readUserInputs().pivot;
    const bias = readUserInputs().bias;

    // 合成する直線ボリューム成分
    const customLinearPotTaper = linearFn( new Array(101), 1.0, bias );

    return [
        {
        color:'deepskyblue',
        key:'10%',
        values: logPotTaper( new Array(101), 0.10 )
                .map((y, x) => ({x: x/100, y: y}))
        },
        {
        color:'green',
        key:'15%',
        values: logPotTaper( new Array(101), 0.15 )
                .map((y, x) => ({x: x/100, y: y}))
        },
        {
        color:'slateblue',
        key:'20%',
        values: logPotTaper( new Array(101), 0.20 )
                .map((y, x) => ({x: x/100, y: y}))
        },
        {
        color: 'lightsteelblue',
        key: 'liner pot(typical)',
        values: linearFn( new Array(101), 1.0, 0.0 )
                .map( (v,i) => ({x: i/100, y: v}) )
        },
        {
        color: 'darkslategray',
        key: 'liner pot',
        values: customLinearPotTaper
                .map( (v,i) => ({x: i/100, y: v}) )
                .filter( pt => 0.0 <= pt.y && pt.y <= 1.0 )
        },
        {
        color: 'thistle',
        key: 'bended line',
        values: bendLineWithPivot( new Array(101), pivot )
                .map( (v,i) => ({x: i/100, y: v}) )
        },
        {
        color: 'orangered',
        key: 'custom taper',
        values: customTaper( pivot, bias, customLinearPotTaper )
                .map( (v,i) => ({x: i/100, y: v}) )
        }
    ];
};

const chartCustomTaper = nv.models.lineChart()
                            .useInteractiveGuideline(true)
                            .showLegend(true)
                            .showXAxis(true)
                            .showYAxis(true)
                            ;

const selectCustomTaper = d3.select('#custom-taper')
                            .append('svg')
                            .attr('width', 320)
                            .attr('height', 320)
                            ;
// カスタムボリュームカーブグラフ
nv.addGraph( () => {
    chartCustomTaper.xAxis
        .axisLabel('Potentiometer position (Normalized)')
        .tickFormat(d3.format(',.2f'));

    chartCustomTaper.yAxis
        .axisLabel('Voltage Output (Normalized)')
        .tickFormat(d3.format(',.2f'));

    selectCustomTaper.datum( customPotTaper() )
                        .transition()
                        .duration(500)
                        .call(chartCustomTaper);

    d3.select('#volSteps').on("input", updateCustomGraph);
    d3.select('#volSteps').on("change", updateCustomGraph);
    d3.select('#taperPivotX').on("input", updateCustomGraph);
    d3.select('#taperPivotY').on("input", updateCustomGraph);
    d3.select('#linerBias').on("input", updateCustomGraph);
    d3.select('#taperPivotX').on("change", updateCustomGraph);
    d3.select('#taperPivotY').on("change", updateCustomGraph);
    d3.select('#linerBias').on("change", updateCustomGraph);

    nv.utils.windowResize(chartCustomTaper.update);
    return chartCustomTaper;
});

const valuesOfAttenuator = () => {
    const pivot = readUserInputs().pivot;
    const bias  = readUserInputs().bias;
    const steps = parseInt(readUserInputs().steps);

    const customLinearPotTaper = linearFn( new Array(steps), 1.0, bias );
    const taper = customTaper( pivot, bias, customLinearPotTaper )

    return {
        steps: steps,
        LM1972:  taper.map( digitalStepLM1972 ),
        PGA2311: taper.map( digitalStepPGA2311 ),
    };
};

// 
const digitalPot = () => {
    vs = valuesOfAttenuator();
    return [
        {
        color:'deepskyblue',
        key:'10%',
        values: logPotTaper( new Array(vs.steps), 0.10 )
                .map( (y,i) => ({x: i, y: 20*Math.log10(y)}) )
        },
        {
        color:'green',
        key:'15%',
        values: logPotTaper( new Array(vs.steps),  0.15)
                .map( (y,i) => ({x: i, y: 20*Math.log10(y)}) )
        },
        {
        color:'slateblue',
        key:'20%',
        values: logPotTaper( new Array(vs.steps), 0.20 )
                .map( (y,i) => ({x: i, y: 20*Math.log10(y)}) )
        },
        {
        color: 'purple',
        key: 'PGA2311',
        values: vs.PGA2311
                    .map( v => gainPGA2311.find( set=>(set[0]==v) )[1] )
                    .map( (v,i) => ({x: i, y: v}) )
        },
        {
        color: 'orange',
        key: 'LM1972',
        values: vs.LM1972
                    .map( v => gainLM1972.find( set=>(set[0]==v) )[1] )
                    .map( (v,i) => ({x: i, y: v}) )
        },
    ];
};

const chartDigitalPot = nv.models.scatterChart()
                        .showLegend(true)
                        .showXAxis(true)
                        .showYAxis(true)
                        ;

const selectDigitalPot = d3.select('#digitalpot-graph')
                            .append('svg')
                            .attr('width', 320)
                            .attr('height', 320)
                            ;

// digital potentiometer graph
nv.addGraph( () => {
    values = valuesOfAttenuator();

    chartDigitalPot.xAxis
        .axisLabel('digital pot travel.');
    chartDigitalPot.yAxis
        .axisLabel('set value')
        .tickFormat(d3.format(',.2f'));

    selectDigitalPot
        .datum( digitalPot() )
        .transition()
        .duration(500)
        .call(chartDigitalPot);

    nv.utils.windowResize(chartDigitalPot.update);
    return chartDigitalPot;
});

//
const updateCustomGraph = () => {
    const d = customPotTaper();
    selectCustomTaper
        .datum( d )
        .transition()
        .duration(500)
        .call(chartCustomTaper);

    nv.utils.windowResize(chartCustomTaper.update);
    //
    selectDigitalPot
        .datum( digitalPot() )
        .transition()
        .duration(500)
        .call(chartDigitalPot);

    nv.utils.windowResize(chartDigitalPot.update);
    //
    updateResultDataArea();
};

//
const updateResultDataArea = () => {
    const value = valuesOfAttenuator();
    const txt = [
        '// Domain of a digital potentiometer [0:' + (value.LM1972.length-1) + ']',
        'attLM1972 = [' + value.LM1972 + '];',
        'attPGA2311 = [' + value.PGA2311 + '];',
    ].join('\n');

    d3.select('#stepdata').text( txt );
};

window.onload = updateResultDataArea;

// 電子ボリュームICの設定値-減衰量グラフ
nv.addGraph( () => {
    //var chart = nv.models.historicalBarChart();
    //var chart = nv.models.lineWithFocusChart();
    //var chart = nv.models.scatterChart();
    const chart = nv.models.lineChart()
                .useInteractiveGuideline(true)
                .showLegend(true)
                .showXAxis(true)
                .showYAxis(true)
                ;

    chart.xAxis
        .axisLabel('Digital Step Value')
        .tickFormat(d3.format(',f'));

    chart.yAxis
        .axisLabel('Channel Attenuation (dB)')
        .tickFormat(d3.format(',.1f'));

    d3.select('#ic-curve')
        .append('svg')
        .attr('width', 320)
        .attr('height', 320)
        .datum( [{
                color:'green',
                key:'PGA2311',
                values: gainPGA2311.map( v => ({x: v[0], y: v[1]}) )
                },
                {
                color:'blue',
                key:'LM1972',
                values: gainLM1972.map( v => ({x: v[0], y: v[1]}) )
                }])
        .transition()
        .duration(500)
        .call(chart)
    ;

    nv.utils.windowResize(chart.update);
    return chart;
});


// クリップ処理(LM1972)
const clipLM1972 = decibel => {
    let d = decibel;
    d = Math.min( d, 0.0 );
    d = Math.max( d, -78.0 );
    // 小数2位以下は捨てる
    d = Math.round(d*10.0) / 10.0;
    // 0.5dB ステップ幅に抑える
    d = Math.round(d/0.5) * 0.5;
    return d;
};

// クリップ処理(PGA2311)
const clipPGA2311 = decibel => {
    let d = decibel;
    d = Math.min( d, 31.5 );
    d = Math.max( d, -95.5 );
    // 小数2位以下は捨てる
    d = Math.round(d*10.0) / 10.0;
    // 0.5dB ステップ幅に抑える
    d = Math.round(d/0.5) * 0.5;
    return d;
};

// 値域よりLM1972の定義域へ写す
const digitalStepLM1972 = y => {
    let d =
        (y == 0.0) ? -78.0 : 20*Math.log10(y);
    d = clipLM1972(d);
    const target = gainLM1972.find( set => (set[1] == d) );
    return target[0];
}

// 値域よりPGA2311の定義域へ写す
const digitalStepPGA2311 = y => {
    let d =
        (y == 0.0) ? -95.5 : 20*Math.log10(y);
    d = clipPGA2311(d);
    const target = gainPGA2311.find( set => (set[1] == d) );
    return target[0];
};

// 最大減衰量(dB)
const MUTE = -100.0;

// PGA2311の設定値 - 減衰値の対応
const gainPGA2311 =
[
 [  0,  MUTE],
 [  1, -95.5], [  2, -95.0], [  3, -94.5], [  4, -94.0], [  5, -93.5], [  6, -93.0],
 [  7, -92.5], [  8, -92.0], [  9, -91.5], [ 10, -91.0], [ 11, -90.5], [ 12, -90.0],
 [ 13, -89.5], [ 14, -89.0], [ 15, -88.5], [ 16, -88.0], [ 17, -87.5], [ 18, -87.0],
 [ 19, -86.5], [ 20, -86.0], [ 21, -85.5], [ 22, -85.0], [ 23, -84.5], [ 24, -84.0],
 [ 25, -83.5], [ 26, -83.0], [ 27, -82.5], [ 28, -82.0], [ 29, -81.5], [ 30, -81.0],
 [ 31, -80.5], [ 32, -80.0], [ 33, -79.5], [ 34, -79.0], [ 35, -78.5], [ 36, -78.0],
 [ 37, -77.5], [ 38, -77.0], [ 39, -76.5], [ 40, -76.0], [ 41, -75.5], [ 42, -75.0],
 [ 43, -74.5], [ 44, -74.0], [ 45, -73.5], [ 46, -73.0], [ 47, -72.5], [ 48, -72.0],
 [ 49, -71.5], [ 50, -71.0], [ 51, -70.5], [ 52, -70.0], [ 53, -69.5], [ 54, -69.0],
 [ 55, -68.5], [ 56, -68.0], [ 57, -67.5], [ 58, -67.0], [ 59, -66.5], [ 60, -66.0],
 [ 61, -65.5], [ 62, -65.0], [ 63, -64.5], [ 64, -64.0], [ 65, -63.5], [ 66, -63.0],
 [ 67, -62.5], [ 68, -62.0], [ 69, -61.5], [ 70, -61.0], [ 71, -60.5], [ 72, -60.0],
 [ 73, -59.5], [ 74, -59.0], [ 75, -58.5], [ 76, -58.0], [ 77, -57.5], [ 78, -57.0],
 [ 79, -56.5], [ 80, -56.0], [ 81, -55.5], [ 82, -55.0], [ 83, -54.5], [ 84, -54.0],
 [ 85, -53.5], [ 86, -53.0], [ 87, -52.5], [ 88, -52.0], [ 89, -51.5], [ 90, -51.0],
 [ 91, -50.5], [ 92, -50.0], [ 93, -49.5], [ 94, -49.0], [ 95, -48.5], [ 96, -48.0],
 [ 97, -47.5], [ 98, -47.0], [ 99, -46.5], [100, -46.0], [101, -45.5], [102, -45.0],
 [103, -44.5], [104, -44.0], [105, -43.5], [106, -43.0], [107, -42.5], [108, -42.0],
 [109, -41.5], [110, -41.0], [111, -40.5], [112, -40.0], [113, -39.5], [114, -39.0],
 [115, -38.5], [116, -38.0], [117, -37.5], [118, -37.0], [119, -36.5], [120, -36.0],
 [121, -35.5], [122, -35.0], [123, -34.5], [124, -34.0], [125, -33.5], [126, -33.0],
 [127, -32.5], [128, -32.0], [129, -31.5], [130, -31.0], [131, -30.5], [132, -30.0],
 [133, -29.5], [134, -29.0], [135, -28.5], [136, -28.0], [137, -27.5], [138, -27.0],
 [139, -26.5], [140, -26.0], [141, -25.5], [142, -25.0], [143, -24.5], [144, -24.0],
 [145, -23.5], [146, -23.0], [147, -22.5], [148, -22.0], [149, -21.5], [150, -21.0],
 [151, -20.5], [152, -20.0], [153, -19.5], [154, -19.0], [155, -18.5], [156, -18.0],
 [157, -17.5], [158, -17.0], [159, -16.5], [160, -16.0], [161, -15.5], [162, -15.0],
 [163, -14.5], [164, -14.0], [165, -13.5], [166, -13.0], [167, -12.5], [168, -12.0],
 [169, -11.5], [170, -11.0], [171, -10.5], [172, -10.0], [173,  -9.5], [174,  -9.0],
 [175,  -8.5], [176,  -8.0], [177,  -7.5], [178,  -7.0], [179,  -6.5], [180,  -6.0],
 [181,  -5.5], [182,  -5.0], [183,  -4.5], [184,  -4.0], [185,  -3.5], [186,  -3.0],
 [187,  -2.5], [188,  -2.0], [189,  -1.5], [190,  -1.0], [191,  -0.5], [192,   0.0],
 [193,   0.5], [194,   1.0], [195,   1.5], [196,   2.0], [197,   2.5], [198,   3.0],
 [199,   3.5], [200,   4.0], [201,   4.5], [202,   5.0], [203,   5.5], [204,   6.0],
 [205,   6.5], [206,   7.0], [207,   7.5], [208,   8.0], [209,   8.5], [210,   9.0],
 [211,   9.5], [212,  10.0], [213,  10.5], [214,  11.0], [215,  11.5], [216,  12.0],
 [217,  12.5], [218,  13.0], [219,  13.5], [220,  14.0], [221,  14.5], [222,  15.0],
 [223,  15.5], [224,  16.0], [225,  16.5], [226,  17.0], [227,  17.5], [228,  18.0],
 [229,  18.5], [230,  19.0], [231,  19.5], [232,  20.0], [233,  20.5], [234,  21.0],
 [235,  21.5], [236,  22.0], [237,  22.5], [238,  23.0], [239,  23.5], [240,  24.0],
 [241,  24.5], [242,  25.0], [243,  25.5], [244,  26.0], [245,  26.5], [246,  27.0],
 [247,  27.5], [248,  28.0], [249,  28.5], [250,  29.0], [251,  29.5], [252,  30.0],
 [253,  30.5], [254,  31.0], [255,  31.5],
];

// LM1972の設定値 - 減衰値の対応
const gainLM1972 =
[
 [  0,   0.0], [  1,  -0.5], [  2,  -1.0], [  3,  -1.5], [  4,  -2.0], [  5,  -2.5],
 [  6,  -3.0], [  7,  -3.5], [  8,  -4.0], [  9,  -4.5], [ 10,  -5.0], [ 11,  -5.5],
 [ 12,  -6.0], [ 13,  -6.5], [ 14,  -7.0], [ 15,  -7.5], [ 16,  -8.0], [ 17,  -8.5],
 [ 18,  -9.0], [ 19,  -9.5], [ 20, -10.0], [ 21, -10.5], [ 22, -11.0], [ 23, -11.5],
 [ 24, -12.0], [ 25, -12.5], [ 26, -13.0], [ 27, -13.5], [ 28, -14.0], [ 29, -14.5],
 [ 30, -15.0], [ 31, -15.5], [ 32, -16.0], [ 33, -16.5], [ 34, -17.0], [ 35, -17.5],
 [ 36, -18.0], [ 37, -18.5], [ 38, -19.0], [ 39, -19.5], [ 40, -20.0], [ 41, -20.5],
 [ 42, -21.0], [ 43, -21.5], [ 44, -22.0], [ 45, -22.5], [ 46, -23.0], [ 47, -23.5],
 [ 48, -24.0], [ 49, -24.5], [ 50, -25.0], [ 51, -25.5], [ 52, -26.0], [ 53, -26.5],
 [ 54, -27.0], [ 55, -27.5], [ 56, -28.0], [ 57, -28.5], [ 58, -29.0], [ 59, -29.5],
 [ 60, -30.0], [ 61, -30.5], [ 62, -31.0], [ 63, -31.5], [ 64, -32.0], [ 65, -32.5],
 [ 66, -33.0], [ 67, -33.5], [ 68, -34.0], [ 69, -34.5], [ 70, -35.0], [ 71, -35.5],
 [ 72, -36.0], [ 73, -36.5], [ 74, -37.0], [ 75, -37.5], [ 76, -38.0], [ 77, -38.5],
 [ 78, -39.0], [ 79, -39.5], [ 80, -40.0], [ 81, -40.5], [ 82, -41.0], [ 83, -41.5],
 [ 84, -42.0], [ 85, -42.5], [ 86, -43.0], [ 87, -43.5], [ 88, -44.0], [ 89, -44.5],
 [ 90, -45.0], [ 91, -45.5], [ 92, -46.0], [ 93, -46.5], [ 94, -47.0], [ 95, -47.5],
 [ 96, -48.0], [ 97, -49.0], [ 98, -50.0], [ 99, -51.0], [100, -52.0], [101, -53.0],
 [102, -54.0], [103, -55.0], [104, -56.0], [105, -57.0], [106, -58.0], [107, -59.0],
 [108, -60.0], [109, -61.0], [110, -62.0], [111, -63.0], [112, -64.0], [113, -65.0],
 [114, -66.0], [115, -67.0], [116, -68.0], [117, -69.0], [118, -70.0], [119, -71.0],
 [120, -72.0], [121, -73.0], [122, -74.0], [123, -75.0], [124, -76.0], [125, -77.0],
 [126, -78.0], [127,  MUTE], [128,  MUTE], [129,  MUTE], [130,  MUTE], [131,  MUTE],
 [132,  MUTE], [133,  MUTE], [134,  MUTE], [135,  MUTE], [136,  MUTE], [137,  MUTE],
 [138,  MUTE], [139,  MUTE], [140,  MUTE], [141,  MUTE], [142,  MUTE], [143,  MUTE],
 [144,  MUTE], [145,  MUTE], [146,  MUTE], [147,  MUTE], [148,  MUTE], [149,  MUTE],
 [150,  MUTE], [151,  MUTE], [152,  MUTE], [153,  MUTE], [154,  MUTE], [155,  MUTE],
 [156,  MUTE], [157,  MUTE], [158,  MUTE], [159,  MUTE], [160,  MUTE], [161,  MUTE],
 [162,  MUTE], [163,  MUTE], [164,  MUTE], [165,  MUTE], [166,  MUTE], [167,  MUTE],
 [168,  MUTE], [169,  MUTE], [170,  MUTE], [171,  MUTE], [172,  MUTE], [173,  MUTE],
 [174,  MUTE], [175,  MUTE], [176,  MUTE], [177,  MUTE], [178,  MUTE], [179,  MUTE],
 [180,  MUTE], [181,  MUTE], [182,  MUTE], [183,  MUTE], [184,  MUTE], [185,  MUTE],
 [186,  MUTE], [187,  MUTE], [188,  MUTE], [189,  MUTE], [190,  MUTE], [191,  MUTE],
 [192,  MUTE], [193,  MUTE], [194,  MUTE], [195,  MUTE], [196,  MUTE], [197,  MUTE],
 [198,  MUTE], [199,  MUTE], [200,  MUTE], [201,  MUTE], [202,  MUTE], [203,  MUTE],
 [204,  MUTE], [205,  MUTE], [206,  MUTE], [207,  MUTE], [208,  MUTE], [209,  MUTE],
 [210,  MUTE], [211,  MUTE], [212,  MUTE], [213,  MUTE], [214,  MUTE], [215,  MUTE],
 [216,  MUTE], [217,  MUTE], [218,  MUTE], [219,  MUTE], [220,  MUTE], [221,  MUTE],
 [222,  MUTE], [223,  MUTE], [224,  MUTE], [225,  MUTE], [226,  MUTE], [227,  MUTE],
 [228,  MUTE], [229,  MUTE], [230,  MUTE], [231,  MUTE], [232,  MUTE], [233,  MUTE],
 [234,  MUTE], [235,  MUTE], [236,  MUTE], [237,  MUTE], [238,  MUTE], [239,  MUTE],
 [240,  MUTE], [241,  MUTE], [242,  MUTE], [243,  MUTE], [244,  MUTE], [245,  MUTE],
 [246,  MUTE], [247,  MUTE], [248,  MUTE], [249,  MUTE], [250,  MUTE], [251,  MUTE],
 [252,  MUTE], [253,  MUTE], [254,  MUTE], [255,  MUTE],
];