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hadoopmarc/oscilloscope.c

Last active January 7, 2024 14:08
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Revisions

  1. hadoopmarc revised this gist Jan 7, 2024. 1 changed file with 1 addition and 1 deletion.
    2 changes: 1 addition & 1 deletion oscilloscope.c
    View file
    Original file line number Diff line number Diff line change
    @@ -24,7 +24,7 @@
    // Original blog: https://www.instructables.com/Arduino-Oscilloscope-poor-mans-Oscilloscope/
    // Original source: https://gist.github.com/chrismeyersfsu/3270419#file-gistfile1-c
    // Pause feature: https://gist.github.com/zsolt-szilagyi/2e4088f6ba0d30c04aa6bc589fb41739
    // Current source:
    // Current source: https://gist.github.com/hadoopmarc/77ecd3d6ab098faa3cbdded3760660db

    import processing.serial.*;

  2. hadoopmarc created this gist Jan 7, 2024.
    132 changes: 132 additions & 0 deletions oscilloscope.c
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    Original file line number Diff line number Diff line change
    @@ -0,0 +1,132 @@
    /*
    * Oscilloscope
    * Gives a visual rendering of analog pin 0 in realtime.
    *
    * This project is part of Accrochages
    * See http://accrochages.drone.ws
    *
    * (c) 2008 Sofian Audry (info@sofianaudry.com)
    *
    * This program is free software: you can redistribute it and/or modify
    * it under the terms of the GNU General Public License as published by
    * the Free Software Foundation, either version 3 of the License, or
    * (at your option) any later version.
    *
    * This program is distributed in the hope that it will be useful,
    * but WITHOUT ANY WARRANTY; without even the implied warranty of
    * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    * GNU General Public License for more details.
    *
    * You should have received a copy of the GNU General Public License
    * along with this program. If not, see <http://www.gnu.org/licenses/>.
    */

    // Original blog: https://www.instructables.com/Arduino-Oscilloscope-poor-mans-Oscilloscope/
    // Original source: https://gist.github.com/chrismeyersfsu/3270419#file-gistfile1-c
    // Pause feature: https://gist.github.com/zsolt-szilagyi/2e4088f6ba0d30c04aa6bc589fb41739
    // Current source:

    import processing.serial.*;

    Serial port; // Create object from Serial class
    IntList vals; // Data received from the serial port
    int[] values;
    float zoom;
    boolean paused;

    void setup()
    {
    size(1280, 600);
    // Open the port that the board is connected to and use the same baudrate as the Arduino
    port = new Serial(this, Serial.list()[0], 2000000);
    values = new int[width];
    zoom = 1.0f;
    paused = false;
    }

    int getY(int val) {
    return (int)(height - val / 1023.0f * (height - 1));
    }

    // Arduino UNO R3 takes about 8000 analog measurements per second.
    // Processing IDE seems to have a minimum buffer size of 96 bytes for serial
    // events to get processed, irrespective of the port.buffer(3) setting or the
    // frameRate of the draw() loop. So, the implementation below reads all values
    // from the buffer, once they are available.
    IntList getValues() {
    IntList vals = new IntList();
    while (port.available() >= 3) {
    if (port.read() == 0xff) {
    int value = port.read() << 8 | port.read();
    vals.append(value);
    }
    }
    return vals;
    }

    void pushValues(IntList vals) {
    for (int i = 0; i < width; i++)
    if (i < width - vals.size()) {
    values[i] = values[i + vals.size()];
    } else {
    values[i] = vals.get(i - width + vals.size());
    }
    }

    void drawLines() {
    stroke(255);

    int displayWidth = (int) (width / zoom);

    int k = values.length - displayWidth;

    int x0 = 0;
    int y0 = getY(values[k]);
    for (int i=1; i<displayWidth; i++) {
    k++;
    int x1 = (int) (i * (width-1) / (displayWidth-1));
    int y1 = getY(values[k]);
    line(x0, y0, x1, y1);
    x0 = x1;
    y0 = y1;
    }
    }

    void drawGrid() {
    stroke(255, 0, 0);
    line(0, height/2, width, height/2);
    }

    void keyReleased() {
    switch (key) {
    case '+':
    zoom *= 2.0f;
    println(zoom);
    if ( (int) (width / zoom) <= 1 )
    zoom /= 2.0f;
    break;
    case '-':
    zoom /= 2.0f;
    if (zoom < 1.0f)
    zoom *= 2.0f;
    break;
    case 'p':
    paused = !paused;
    break;
    }
    }

    void draw()
    {
    if (paused) {
    return;
    }

    background(0);
    drawGrid();
    vals = getValues();
    if (vals.size() > 0) {
    pushValues(vals);
    }
    drawLines();
    }