Question

我有 flex sensor 连接 arduino lily pad 和47k ohms电阻。

我的问题是我无法从 flex sensors 获得一致的值：有时候，即使Flex传感器没有处于弯曲状态，我也会得到非常奇怪的读数

我尝试更改straight_resistance和bend_resistance的值，但它似乎无法解决问题。

这是我的代码，期待寻求帮助。

const int FLEX_PIN = A0; // Pin connected to voltage divider output

// Measure the voltage at 5V and the actual resistance of your
// 47k resistor, and enter them below:
const float VCC = 4.98; // Measured voltage of Ardunio 5V line (r1/r1+r2)5
const float R_DIV = 47500.0; // Measured resistance of 3.3k resistor

// Upload the code, then try to adjust these values to more
// accurately calculate bend degree.
const float STRAIGHT_RESISTANCE = 24248750.00; // resistance when     straight 
const float BEND_RESISTANCE = 48544996.00; // resistance at 90 deg

void setup() 
{
  Serial.begin(9600);
  pinMode(FLEX_PIN, INPUT);
}

void loop() 
{
  // Read the ADC, and calculate voltage and resistance from it
  int flexADC = analogRead(FLEX_PIN);
  float flexV = flexADC * VCC / 1023.0;
  float flexR = R_DIV * (VCC / flexV - 1.0);
  Serial.println("Resistance: " + String(flexR) + " ohms");

  // Use the calculated resistance to estimate the sensor's
  // bend angle:
  float angle = map(flexR, STRAIGHT_RESISTANCE, BEND_RESISTANCE,
               0, 90.0);
  Serial.println("Bend: " + String(angle) + " degrees");
  Serial.println();

  delay(750);
}

Answer 1

您的代码中的以下值似乎不对。这些是MOhms中的值，而不是kOhms。

const float STRAIGHT_RESISTANCE = 24248750.00; // resistance when     straight 
const float BEND_RESISTANCE = 48544996.00; // resistance at 90 deg

另一个问题是map（）函数只适用于整数！在map（）函数使用它们之前，传入的浮点值将转换为整数。

带有arduino的柔性传感器

1 个答案: