Understanding Delays in Arduino Programming

Timing issues are often present in programming, especially when working with microcontrollers like the Arduino. In this article, we'll explore one of the well-known Arduino functions - `delay()` - and its alternative, `millis()`. We'll also discuss the importance of timing in programming and how to effectively use these functions in your projects.

The Delay Function

`delay()` is a simple function that pauses the program for a specified number of milliseconds. It's commonly used when you need to create a delay between two events or operations. For example, you might use `delay(1000)` to pause the program for 1 second before performing an action.

The Millis Function

On the other hand, `millis()` is a function that returns the number of milliseconds that have passed since the program started. This function is often used in conjunction with `delay()` or as a way to measure time intervals between events.

Real-Time Applications

In real-time applications like remote control of generator sets, timing is crucial. For example, you might need to ensure that a generator starts within a certain timeframe after being turned on. In such cases, using `delay()` and `millis()` can help you achieve the desired timing.

Example Code

Here's an example code snippet from Terry King's project, which demonstrates the use of `millis()` in a real-time application:

```cpp

MsChokewasClosed = choke_millis.elapsed() // Record this start attempt

GeneratorState = RUNNING_NORMAL_STATE // Will open choke, stop starter

If (AC_powerDetected) // The generator engine has started

Serial.println('STARTER ran too long, failure')

If (starter_millis.elapsed() >= MAX_STARTER_MS)

Serial.println(starter_millis.elapsed())

If (choke_millis.elapsed() >= MAX_CHOKE_MS) // Long enough time

Serial.println('ATTEMPTING TO START ENGINE')

```

In this code, `millis()` is used to track the time intervals between events and ensure that the generator starts within a certain timeframe.

In conclusion, timing is a critical aspect of programming, especially in real-time applications like remote control of generator sets. The `delay()` and `millis()` functions are essential tools in your Arduino toolbox, helping you create delays and measure time intervals between events. By understanding how to effectively use these functions, you can build robust and reliable projects that meet the required timing specifications.

Arduino delay seconds