Ciao a tutti! Ho bisogno di leggere un treno d'onda da un sensore che mi spara la rilevazione in PWM (sono 3 letture separate da un segnale LOW). Questo è il codice riadattato preso da uno sketch trovato sul web (RCArduino: How To Read an RC Receiver With A Microcontroller - Part 1):
// First Example in a series of posts illustrating reading an RC Receiver with
// micro controller interrupts.
//
// Subsequent posts will provide enhancements required for real world operation
// in high speed applications with multiple inputs.
//
// http://rcarduino.blogspot.com/
//
// Posts in the series will be titled - How To Read an RC Receiver With A Microcontroller
// See also http://rcarduino.blogspot.co.uk/2012/04/how-to-read-multiple-rc-channels-draft.html
#define THROTTLE_SIGNAL_IN 0 // INTERRUPT 0 = DIGITAL PIN 2 - use the interrupt number in attachInterrupt
#define THROTTLE_SIGNAL_IN_PIN 2 // INTERRUPT 0 = DIGITAL PIN 2 - use the PIN number in digitalRead
#define NEUTRAL_THROTTLE 1500 // this is the duration in microseconds of neutral throttle on an electric RC Car
volatile int nThrottleIn = NEUTRAL_THROTTLE; // volatile, we set this in the Interrupt and read it in loop so it must be declared volatile
volatile unsigned long ulStartPeriod = 0; // set in the interrupt
volatile boolean bNewThrottleSignal = false; // set in the interrupt and read in the loop
// we could use nThrottleIn = 0 in loop instead of a separate variable, but using bNewThrottleSignal to indicate we have a new signal
// is clearer for this first example
void setup()
{
// tell the Arduino we want the function calcInput to be called whenever INT0 (digital pin 2) changes from HIGH to LOW or LOW to HIGH
// catching these changes will allow us to calculate how long the input pulse is
attachInterrupt(THROTTLE_SIGNAL_IN,calcInput,CHANGE);
Serial.begin(9600);
}
void loop()
{
// if a new throttle signal has been measured, lets print the value to serial, if not our code could carry on with some other processing
if(bNewThrottleSignal)
{
Serial.println(nThrottleIn);
// set this back to false when we have finished
// with nThrottleIn, while true, calcInput will not update
// nThrottleIn
bNewThrottleSignal = false;
}
// other processing ...
}
void calcInput()
{
// if the pin is high, its the start of an interrupt
if(digitalRead(THROTTLE_SIGNAL_IN_PIN) == HIGH)
{
// get the time using micros - when our code gets really busy this will become inaccurate, but for the current application its
// easy to understand and works very well
ulStartPeriod = micros();
}
else
{
// if the pin is low, its the falling edge of the pulse so now we can calculate the pulse duration by subtracting the
// start time ulStartPeriod from the current time returned by micros()
if(ulStartPeriod && (bNewThrottleSignal == false))
{
nThrottleIn = (int)(micros() - ulStartPeriod);
ulStartPeriod = 0;
// tell loop we have a new signal on the throttle channel
// we will not update nThrottleIn until loop sets
// bNewThrottleSignal back to false
bNewThrottleSignal = true;
}
}
}
Ottengo effettivamente 3 letture ma non ho capito dove posso memorizzare i singoli valori delle singole letture. Avrei bisogno di qualcosa del tipo
Serial.print("Valore1: ");
Serial.println(lettura1);
Serial.print("Valore2: ");
Serial.println(lettura2);
Serial.print("Valore3: ");
Serial.println(lettura3);
ma non riesco a capire come fare.
Qualche idea?
Grazie!
)
