Hello everybody,
I have a custom board with ESP32 and there is 3 LEDs.
Depending on the board state there are different LEDs blinking combinations, so I want to understand what is the best way to implement on my code these LEDs functions.
I use vTaskDelay() to block the LED in ON or OFF state, but if I need to change the LEDs blinking function ESP32 has to wait the delay time before changing, but I want the change to be immediate.
Hope in your help.
led Task
Re: led Task
hi Hack-Mike,
if you want to change the state of the LEDs immediate. please don't use the vTaskDelay() this "blocks" or "locks" that bit of code. I rather use millis() for a big delay. you could look at blink without delay of how to use millis() (http://www.arduino.cc/en/Tutorial/BlinkWithoutDelay)
if you want to change the state of the LEDs immediate. please don't use the vTaskDelay() this "blocks" or "locks" that bit of code. I rather use millis() for a big delay. you could look at blink without delay of how to use millis() (http://www.arduino.cc/en/Tutorial/BlinkWithoutDelay)
Code: Select all
/*
Blink without Delay
Turns on and off a light emitting diode (LED) connected to a digital pin,
without using the delay() function. This means that other code can run at the
same time without being interrupted by the LED code.
The circuit:
- Use the onboard LED.
- Note: Most Arduinos have an on-board LED you can control. On the UNO, MEGA
and ZERO it is attached to digital pin 13, on MKR1000 on pin 6. LED_BUILTIN
is set to the correct LED pin independent of which board is used.
If you want to know what pin the on-board LED is connected to on your
Arduino model, check the Technical Specs of your board at:
https://www.arduino.cc/en/Main/Products
created 2005
by David A. Mellis
modified 8 Feb 2010
by Paul Stoffregen
modified 11 Nov 2013
by Scott Fitzgerald
modified 9 Jan 2017
by Arturo Guadalupi
This example code is in the public domain.
http://www.arduino.cc/en/Tutorial/BlinkWithoutDelay
*/
// constants won't change. Used here to set a pin number:
const int ledPin = LED_BUILTIN;// the number of the LED pin
// Variables will change:
int ledState = LOW; // ledState used to set the LED
// Generally, you should use "unsigned long" for variables that hold time
// The value will quickly become too large for an int to store
unsigned long previousMillis = 0; // will store last time LED was updated
// constants won't change:
const long interval = 1000; // interval at which to blink (milliseconds)
void setup() {
// set the digital pin as output:
pinMode(ledPin, OUTPUT);
}
void loop() {
// here is where you'd put code that needs to be running all the time.
// check to see if it's time to blink the LED; that is, if the difference
// between the current time and last time you blinked the LED is bigger than
// the interval at which you want to blink the LED.
unsigned long currentMillis = millis();
if (currentMillis - previousMillis >= interval) {
// save the last time you blinked the LED
previousMillis = currentMillis;
// if the LED is off turn it on and vice-versa:
if (ledState == LOW) {
ledState = HIGH;
} else {
ledState = LOW;
}
// set the LED with the ledState of the variable:
digitalWrite(ledPin, ledState);
}
}
Re: led Task
Hi sebasdt,
Yes I know Wiring and Arduino function mills(), but I'm using ESP-IDF with freeRTOS.
So I'm looking for the best way with the freeRTOS, I thought to use xTaskGetTickCount() like millis() functions, but I want to understand if this is the best method.
Yes I know Wiring and Arduino function mills(), but I'm using ESP-IDF with freeRTOS.
So I'm looking for the best way with the freeRTOS, I thought to use xTaskGetTickCount() like millis() functions, but I want to understand if this is the best method.
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- Posts: 9718
- Joined: Thu Nov 26, 2015 4:08 am
Re: led Task
You could implement your delay as an xQueueReceive with the delay you'd normally wait as the timeout. If the receive times out, you continue as it it were a wait. If it actually receives something, you use that information to switch to a different pattern. Other tasks can then set the blinking pattern by putting the desired pattern into the queue.
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