fsr 和 LCD 的 Arduino 问题

Question

我正在做一个需要使用 arduino uno、4 个力传感器和 16x2 LCD 的项目。我正在尝试通过按钮的实现将力传感器的读数显示在 LCD 上。例如。如果我按下向上按钮，它应该显示第一个力传感器读数。问题是它只显示大量的 143164976.0000，即使没有对其施加任何力。请就我的编码是否有问题提出建议。

    int iForceSensorReading;     // the analog reading from the FSR resistor divider
    int iForceSensorReading1;
    int iForceSensorReading2;
    int iForceSensorReading3;
    int iForceSensorVoltage;     // the analog reading converted to voltage
    int iForceSensorVoltage1;
    int iForceSensorVoltage2;
    int iForceSensorVoltage3;
    unsigned long ulForceSensorResistance;// The voltage converted to resistance, can be                 very big so make "long"
    unsigned long ulForceSensorResistance1;
    unsigned long ulForceSensorResistance2;
    unsigned long ulForceSensorResistance3;
    unsigned long ulForceSensorConductance;
    unsigned long ulForceSensorConductance1;
    unsigned long ulForceSensorConductance2;
    unsigned long ulForceSensorConductance3;
    float FsrForce = 0;       // Finally, the resistance converted to force
    float FsrForce1 = 0;
    float FsrForce2 = 0;
    float FsrForce3 = 0; 
    #include <Wire.h>
    #include <Adafruit_MCP23017.h>
    #include <Adafruit_RGBLCDShield.h>
    Adafruit_RGBLCDShield lcd = Adafruit_RGBLCDShield();
    #define RED 0x1
    #define YELLOW 0x3
    #define GREEN 0x2
    #define TEAL 0x6
    #define BLUE 0x4
    #define VIOLET 0x5
    #define WHITE 0x7
    void setup(void){
      Serial.begin(9600);   // send debugging information via the Serial monitor
      lcd.begin(16, 2);
      lcd.print("Hand Muscle");
      lcd.setCursor(0,1);
      lcd.print("Meter");
      lcd.setBacklight(WHITE);
    }
    uint8_t i=0;
    void loop(void){
    uint8_t buttons = lcd.readButtons();
    iForceSensorReading = analogRead(A0);//read index finger pressure
    delay(30);
    // analog voltage reading ranges from about 0 to 1023 which maps to 0V to 5V (=                 5000mV)
    iForceSensorVoltage = map(iForceSensorReading, 0, 1023, 0, 5000);
    ulForceSensorConductance = conductanceFunction(ulForceSensorResistance,                 iForceSensorVoltage);
    if (ulForceSensorConductance <= 1000){
        FsrForce = ulForceSensorConductance / 80;    
        } 
    else{
        FsrForce = ulForceSensorConductance - 1000;
        FsrForce /= 30;
       }
    iForceSensorReading1 = analogRead(A1);//read middle finger pressure
    delay(30);
    iForceSensorVoltage1 = map(iForceSensorReading1, 0, 1023, 0, 5000);
    if (iForceSensorVoltage1 == 0){
      } 
    else{
    ulForceSensorConductance1 = conductanceFunction(ulForceSensorResistance1,         iForceSensorVoltage1);
    delay(30);
      }
    if (ulForceSensorConductance1 <= 1000){
        FsrForce1 = ulForceSensorConductance1 / 80;
        } 
    else{
    FsrForce1 = ulForceSensorConductance1 - 1000;
    FsrForce1 /= 30;  
        }
    iForceSensorReading2 = analogRead(A2);// read ring finger pressure
    delay(30);
    iForceSensorVoltage2 = map(iForceSensorReading2, 0, 1023, 0, 5000);
    ulForceSensorConductance2 = conductanceFunction(ulForceSensorResistance2,         iForceSensorVoltage2);
    if (ulForceSensorConductance2 <= 1000){
    FsrForce2 = ulForceSensorConductance2 / 80;
      }
    else{
    FsrForce2 = ulForceSensorConductance2 - 1000;
    FsrForce2 /= 30;   
      }
    iForceSensorReading3 = analogRead(A3);//read little finger pressure
    delay(30);
    iForceSensorVoltage3 = map(iForceSensorReading3, 0, 1023, 0, 5000);
    ulForceSensorConductance3 = conductanceFunction(ulForceSensorResistance3,         iForceSensorVoltage3);
    if (ulForceSensorConductance3 <= 1000) 
    {FsrForce3 = ulForceSensorConductance3 / 80;    
    }else 
    {FsrForce3 = ulForceSensorConductance3 - 1000;
     FsrForce3 /= 30;   
     }
    if (buttons) {
        lcd.clear();
        lcd.setCursor(0,0);
        if (buttons & BUTTON_UP) {
        lcd.print("Index Finger: ");
        lcd.setCursor(0,1);
        lcd.print(FsrForce,DEC);
        lcd.setBacklight(WHITE);
        }
        if (buttons & BUTTON_DOWN) {
        lcd.print("Little Finger: ");
        lcd.setCursor(0,1);
        lcd.print(FsrForce3,DEC); 
        lcd.setBacklight(WHITE);
        }
        if (buttons & BUTTON_LEFT) {
        lcd.print("Middle Finger: ");
        lcd.setCursor(0,1);
        lcd.print(FsrForce1,DEC); 
        lcd.setBacklight(WHITE);
        }
        if (buttons & BUTTON_RIGHT) {
        lcd.print("Ring Finger: ");
        lcd.setCursor(0,1);
        lcd.print(FsrForce2,DEC);  
        lcd.setBacklight(WHITE);
        }
        if (buttons & BUTTON_SELECT) {
        lcd.print("SELECT ");
        lcd.setBacklight(WHITE);
        }
      }
    }
    // The voltage = Vcc * R / (R + FSR) where R = 10K and Vcc = 5V
    // so FSR = ((Vcc - V) * R) / V  
    int conductanceFunction(long x, long y)
    {long result;
     x = 5000 - y; // fsrVoltage is in millivolts so 5V = 5000mV
     x *= 10000; // 10K resistor
     x /= y;
     result = 1000000/x; //ulForceSensorConductance2 = 1000000 measured in micromhos
     return result;
    }

Answer 1

第一个可能的问题是，这种症状听起来像是有符号与无符号的冲突。我在您的代码中看到以下调用

ulForceSensorConductance = conductanceFunction(ulForceSensorResistance,                 iForceSensorVoltage);

在哪里

int conductanceFunction(long x, long y)

但是

int iForceSensorVoltage;

您将 int(signed) 传递给第二个参数。在数学上使用它并创建

的结果变量

long result;

并将其作为 INT 返回。

您可能遇到其他问题的地方。 您应该遵循一些基本的诊断程序。 假设这个问题出现在所有频道上。如果不是，那么它可能是电气的。 专注于一个渠道。

输入各种变量的打印，以查看按预期移动的内容并验证数学是否符合预期