I simply want some code that turns an LED on for a second then off for a second but use millis for a delay.
const int ledPinPower = 8; // the pin the power LED is connected to
int countMillis = 0;
int milliss = 1;
void setup() {
pinMode(ledPinPower, OUTPUT); // Declare the power LED as an output
}
void loop() {
if (milliss = 1) {
digitalWrite(ledPinPower, HIGH); // Turn the power LED on
countMillis = millis();
while (millis() - countMillis < 1000) {
while (true);
}
digitalWrite(ledPinPower, LOW); // Turn the power LED on
countMillis = millis();
while (millis() - countMillis < 1000) {
while (true);
}
}
}
Above is my current code, the problem is the LED stays always on!
const int ledPinPower = 8; // the pin the power LED is connected to
int countMillis = 0;
int milliss = 1;
void setup() {
pinMode(ledPinPower, OUTPUT); // Declare the power LED as an output
}
void loop() {
if (milliss = 1) {
digitalWrite(ledPinPower, HIGH); // Turn the power LED on
countMillis = millis();
while (millis() - countMillis < 1000);
digitalWrite(ledPinPower, LOW); // Turn the power LED on
countMillis = millis();
while (millis() - countMillis < 1000);
}
}
However, this is not good practice. If you want to delay, you just need to use delay() function. If you want to blink without delay, see BlinkWithoutDelay tutorial
This is an example of how you might use millis() "properly" to blink the LED. You can add some simple logic to make it just blink once. (Compiles, not tested for bugs...)
const byte ledPinPower = 8; // the pin the power LED is connected to
unsigned long countMillis = 0;
unsigned long countNow = 0;
bool bLEDState;
void setup()
{
pinMode( ledPinPower, OUTPUT ); // Declare the power LED as an output
bLEDState = false;
}//setup
void loop()
{
countNow = millis();
if( countNow - countMillis >= 1000ul )
{
countMillis = countNow;
if( bLEDState == true )
{
bLEDState = false;
digitalWrite( ledPinPower, LOW );
}//if
else
{
bLEDState = true;
digitalWrite( ledPinPower, HIGH );
}//if
}//if
}//loop
....ah I see it turns it into a unsigned long constant!!!
I have applied Blakfin's code (Thanks Blackfin!) to this section of code in a program I am writing:
unsigned long countMillisTempDelay = 0;
unsigned long countMillisNowTempDelay = 0;
-------------------------------------------------------------------------------------------------------------
/*TURN AIRCON ON/OFF TURN TEMPERATURE UP/DOWN*/
countMillisNowTempDelay = millis();
int chk = DHT11.read(DHT11PIN); //read value from temp + humidity sensor
-------------------------------------------------------------------------------------------------------------
chk = DHT11.read(DHT11PIN); //read value from temp + humidity sensor
if (DHT11.temperature > turnAirconOnTemp && millis() - timeSinceAirconTouched > setTimeSinceAirconTouched) { //if the temperature gets to hot and it has been over ? minutes since we have touched/controlled the aircon
if ( countMillisNowTempDelay - countMillisTempDelay >= 1000ul ) {
chk = DHT11.read(DHT11PIN); //read value from temp + humidity sensor
if (DHT11.temperature > turnAirconOnTemp && millis() - timeSinceAirconTouched > setTimeSinceAirconTouched) { //if the temperature gets to hot and it has been over ? minutes since we have touched/controlled the aircon
if ( countMillisNowTempDelay - countMillisTempDelay >= 1000ul ) {
chk = DHT11.read(DHT11PIN); //read value from temp + humidity sensor
if (DHT11.temperature > turnAirconOnTemp && millis() - timeSinceAirconTouched > setTimeSinceAirconTouched) { //if the temperature gets to hot and it has been over ? minutes since we have touched/controlled the aircon
if ( countMillisNowTempDelay - countMillisTempDelay >= 1000ul ) {
if (nCurrentThruWire > minCurrentAirconFan) { //if the aircon is on
TempDown(); //turn the temperature down to 16°
delay (1000);
Mode(); //change the mode to cooling
delay (1000);
TempUp(); //turn the temperature upto 21°
delay (1000);
timeSinceAirconTouched = millis(); //remember the current millis
}
if (nCurrentThruWire < minCurrentAirconStandby) { //if aircon is off
PowerButton(); //turn aircon on
delay (1000);
TempDown(); //turn the temperature down to 16°
delay (1000);
Mode(); //change the mode to cooling
delay (1000);
TempUp();//turn the temperature upto 21°
delay (1000);
timeSinceAirconTouched = millis(); //remember the current millis
}
}
}
}
}
}
}
The idea is to not delay between checking the temperature.
"Blackfin's" code is really just a re-statement of, but alas a backward step from, the standard blink without delay example. It's bad practice to put numbers like the 1000 in the code; the original has it handily available as a (nicely commented) variable right near the top:
const long interval = 1000; // interval at which to blink (milliseconds)
... where it's easy to change without hunting for it.
The demo Several Things at a Time is an extended example of BWoD and illustrates the use of millis() to manage timing without blocking. It may help with understanding the technique. It flashes 3 LEDs.
