mirror of
https://github.com/m5stack/M5StickC.git
synced 2026-05-20 10:25:54 -07:00
TinyuChiu
93 lines
3.3 KiB
Arduino
93 lines
3.3 KiB
Arduino
/*
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*******************************************************************************
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* Copyright (c) 2023 by M5Stack
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* Equipped with M5StickC sample source code
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* 配套 M5StickC 示例源代码
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* Visit for more information: https://docs.m5stack.com/en/core/m5stickc
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* 获取更多资料请访问: https://docs.m5stack.com/zh_CN/core/m5stickc
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*
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* Describe: Hall sensor. 霍尔传感器
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* Date: 2021/7/27
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*******************************************************************************
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The ESP32 MCU has build in Hall sensor. ESP32 MCU内置霍尔传感器
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It is not very suscescible but if you bring a magnet close to the
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upper screen you will see the influence on the measurement.
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In this example we use some low pass filters to get rid of the noise.
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*/
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#include <M5StickC.h>
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#define HORIZONTAL_RESOLUTION 80 // 屏幕水平分辨率
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#define VERTICAL_RESOLUTION 160 // 屏幕竖直分辨率
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#define POSITION_OFFSET_Y 20
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uint16_t oldSignal[HORIZONTAL_RESOLUTION];
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float ESP32_hallRead() // ESP32 hall value read. ESP32霍尔值读取
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{
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float value = 0;
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int count = 400;
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// mean value filter. 数据低通滤波器
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for (int n = 0; n < count; n++) value += hallRead();
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return value / count * 10;
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}
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float HallOffset =
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0; ////Store the initial value of magnetic force. 存储磁力的初值
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void setup() {
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M5.begin(); // Init M5StickC. 初始化M5StickC
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M5.Lcd.printf("\nESP32 Hall sensor:"); // Screen printout. 屏幕打印输出
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HallOffset =
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ESP32_hallRead(); // callibrate the output value to the magnetic field
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// at start up. 在启动时将输出值校准到磁场
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}
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float LowPassFilteredValue = 0;
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void showSignal() {
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int n;
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int oldx;
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int oldy;
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int oldSig;
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int x, y;
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for (n = 0; n < HORIZONTAL_RESOLUTION;
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n++) // 在水平分辨率内,每个像素点根据计算得到的磁力大小绘制
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{ // Within the horizontal resolution, each pixel is drawn according to the
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// calculated magnetic force
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x = n;
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float value =
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ESP32_hallRead() - HallOffset; // Reduce the influence of own
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// magnetism. 减少自身磁力的影响
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LowPassFilteredValue += (value - LowPassFilteredValue) * 0.05;
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M5.Lcd.setCursor(30, 17);
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M5.Lcd.print((int)LowPassFilteredValue);
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M5.Lcd.print(" ");
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M5.Lcd.setCursor(0, 40);
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y = map(
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value, -127, 127, VERTICAL_RESOLUTION,
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POSITION_OFFSET_Y); // 将value映射至-30~30的范围内,以免绘制超出屏幕
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if (n > 0) {
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// delete old line element. 删除上次画的线
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M5.Lcd.drawLine(oldx, oldSig, x, oldSignal[n], BLACK);
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// draw new line element. 画新的线
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if (n < HORIZONTAL_RESOLUTION -
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1) // don't draw last element because it would generate
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// artifacts. 不能绘制最后一个像素
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{
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M5.Lcd.drawLine(oldx, oldy, x, y, GREEN);
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}
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}
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oldx = x;
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oldy = y;
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oldSig = oldSignal[n];
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oldSignal[n] = y;
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}
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}
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void loop(void) {
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showSignal();
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}
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