Gauss meter --- Hall-Effect sensor with Arduino

自讀書時候認識磁石有南/北極...外,往後是什少再接觸其理論的,現連關於磁場方面的什麼單位也說不出了

玩過吓Arduino亦發現了有值幾豪紙的Hall-effect sensor模塊, 其對磁場有測量作用,故閑來摸了吓

選用了隻SS49E帶線性輸出的霍爾元件:

看了說明書,斗了個多小時編程如下:

/*******************************************************
49E Hall-Effect:
1.4 ~3.0mV/GS, Linear Hall-effect sensors
South : output 0.9~2.5V (-1200 ~ 0 Gauss)
North : output    2.5~4.2V    (0 ~ +1200 Gauss)
Vcc 2.3~10V (6 mA at 5 Vdc)

********************************************************/
//Vcc conected to 3.3V (stabilize)

#include <LiquidCrystal.h>
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);                                     //select the pins used on the LCD panel, pin 10 for black light control

#define Hall_Effect A1                                                 //connect to Hall Effect sensor output pin

int Hall_Effect_normal = 0;                                              //Hall Effect sensor quiescent output voltage

void setup() {
  lcd.begin(16, 2);                                                    //Initialise the LCD
  lcd.clear();

  Hall_Effect_normal = analogRead(Hall_Effect);                         //reading the Hall Effect sensor normal output
  lcd.print("ADC: ");
  lcd.setCursor(0,1);
  lcd.print(Hall_Effect_normal);
  delay(300);
  lcd.clear();

}

void loop() {
  int Hall_out = analogRead(Hall_Effect);                               //reading the output of Hall Effect sensor

  float Hall_volt =  float(Hall_out) / 1023 * 5;                         //change to Voltage
  lcd.setCursor(0,0);
  lcd.print(Hall_volt);
  lcd.print(" V (ADC ");
  lcd.print(Hall_out);
  lcd.print(")  ");
  lcd.setCursor(0,1);
  lcd.print("                ");

  if ( Hall_out > (Hall_Effect_normal +1) ){                            //North: Hall_out is 1.61~2.6V (2.38~4.2V for 5V Vcc) ; "+1" is for ADC tolerance
   lcd.setCursor(0,1);
   lcd.print("North  ");
   lcd.print(map(Hall_out, Hall_Effect_normal, 530, 0, 1200));          //map to Gauss;  "530" is max. of ADC reading
   lcd.print(" GS    ");}

  if ( Hall_out < (Hall_Effect_normal -1) ){                            //South: Hall_out 0.75~1.61V (0.9~2.38V for 5V Vcc)
   lcd.setCursor(0,1);
   lcd.print("South ");
   lcd.print(map(Hall_out, 157, Hall_Effect_normal, -1200, 0));          //map to Gauss;  "157" is min. of ADC reading
   lcd.print(" GS    ");}

  delay(100);

}

測試了磁石放不同距離的結果:
Gauss meter.jpg

感覺磁力強度與距離成非線性變化都很大, 此Sensor亦易滿度飽和,此製作並沒有較準及調試, 故只作玩具級參考吓!
幾豪紙用來淨試測磁石的南/北極以不錯了

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hon829

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發表於 2019-9-12 00:42 | 只看該作者

本帖最後由 hon829 於 2019-9-12 00:51 編輯

另一陽春的做法是用手機Apps: Gauss Meter
https://play.google.com/store/ap ... smeter&hl=zh_TW

確認手機有magnetic sensor : MMC3630KJ (full scale range of +-30 Gauss)
Gauss Meter A.jpg