求助arduino 测量大于5v电压疑问
下述代码例子是通过2个1K电阻进行分压，来测量范围0-10v的电压，例子中resistorFactor = 1023.0 / (R2/(R1 + R2));这句是不是写错了？应该是resistorFactor = 1023.0 * (R2/(R1+R2)); 这样结果正好是511，与下述图表中的value of resistorFactor 吻合。/*
DisplayMoreThan5V sketch
prints the voltage on analog pin to the serial port
Do not connect more than 5 volts directly to an Arduino pin.
*/
const float referenceVolts = 5; // the default reference on a 5-volt board
//const float referenceVolts = 3.3;// use this for a 3.3-volt board
const float R1 = 1000; // value for a maximum voltage of 10 volts
const float R2 = 1000;
// determine by voltage divider resistors, see text
const float resistorFactor = 1023.0 / (R2/(R1 + R2));//此处是否应该是resistorFactor = 1023.0 * (R2/(R1+R2));
const int batteryPin = 0; // +V from battery is connected to analog pin 0
void setup()
{
Serial.begin(9600);
}
void loop()
{
int val = analogRead(batteryPin);// read the value from the sensor
float volts =
(val / resistorFactor) * referenceVolts ; // calculate the ratio
Serial.println(volts);// print the value in volts
}
you are right！ 对不对，自己实际测试一下便知~
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