When learning how to use an Arduino, it is important to understand how to conclude any programs that you run.
This will help prevent errors and protect your hardware from damage.
There are a few different ways to stop running Arduino software, and the most appropriate method will depend on your goals for the project.
However, in general, the easiest way to stop this program type is to use the reset button on the board. This will cause the program to start from the beginning, which can be useful for debugging purposes. Additionally, you can use the bootloader to erase the contents of the board or to upload a new sketch.
Finally, if you are using an Arduino IDE, you can click on the “Stop” button in the toolbar to reset the board and stop any running code. By understanding how to cancel the working Arduino program, you will be able to more effectively use this powerful tool for your projects.
Methods of Finishing the Arduino Program:
1) Turn off the power – in such a way you will unplug the software safely
The software should be carefully disconnected from a power source at any time. When unplugged, it will cease operating its current program and almost all of its memory. The program will reset any non-volatile data stored in the EEPROM and program memory [1]. When you restore the power outage, the program automatically executes its most recent sketch from its setup().
However, any program variables will still be stored in the volatile random access memory (RAM).
When the power is restored, a program can be reset:
- It executes the
setup()function again; - All information has vanished, and all variables have been erased;
- All peripherals will have to be configured again;
When the power is shut off, variables and data may be safely stored using the EEPROM. This protocol type does not lose memory when the power is disconnected. The EEPROM is a type of non-volatile memory that does not get wiped when a program is reset or loses power. It can be compared to a tiny SD card for the software.
2) Ways to reset the programs – use the button or code
There is a soft/hard reset button on the side of the hardware that can cease and reboot the program to the default settings. When it is pressed, the reboot option causes the microcontroller to shut down.
If your device has a problem with the WiFi chip, for example, it will not be reset until you remove power from the board. Peripherals like microSD cards and USB ports will still be in their last state if your gadget has a problem with the WiFi chip, and they should be initialized again.
If the button is depressed for 10 milliseconds, the microprocessor will be reset. Any data that isn’t stored in the EEPROM or program memory will be lost when the microcontroller is restarted.
The reset button will:
- Stop the current sketch from running;
- Restart the sketch from
setup(); - Erase any data stored in variables in RAM;
- Not erase any data stored in EEPROM;
To use the reset button, press and release it quickly. The LED on the software will turn off, indicating that it is no longer running the current sketch. Pressing and holding the reset button for longer than a few seconds will cause the program to restart its bootloader, which may be used to upload a new sketch.
3) Cancel the software loop from running by causing the pause
If you want to stop a loop from running, you can use the break keyword. The break keyword will cause the program to exit the current loop and continue running the rest of the sketch.
If your software gets trapped in an infinite loop that you need to stop executing, there is a command available in a sketch that can be utilized to free oneself from the loop.
The software may quit a loop with the break statement. When writing a sketch that contains an infinite loop, putting the break keyword at the end of it instructs the program to leave. This does not apply to the loop function, which can be terminated using return.
For example, if you have a for loop that is supposed to run 10 times, but you want to stop it after 5 iterations, you can use the break keyword.
4) Trap the program running in a loop to cancel it from executing the wrong code lines
One of the most common ways to stop the program from executing code is by trapping it in a loop. This can be done using a number of different techniques, such as writing conditional statements, using timers, or triggering interrupts.
For example, if you want to control when your sketch runs loops based on time or incoming sensor data, you can create conditional checks for these conditions and add them to your code.
5) Consider using the Sleep Mode option to cancel the program
Entering Sleep Mode puts the program in a low-power state that can be maintained for weeks or months at a time without harming the device. It is possible to choose how you want the program to be awakened before shutting it down. The software is generally set to wake up by timer or via an external interrupt. Depending on which board you’re using, you can select from a variety of sleep modes.
The program can enter Sleep Mode by using the sleep() method. This instructs the software to cease all operations, except for timer-based tasks, until an interrupt occurs.
Once the program is in Sleep Mode, you can wake it up by triggering an external interrupt or a built-in timer. Conditional statements and other commands allow you to create a variety of programs that use Sleep Mode to control when your device executes code.
6) Execute an external relay to cut the power off to the program
If you need to stop an Arduino from running a specific piece of code without resetting or halting it, you can apply an external relay option to cut the power to the device. This will allow you to easily shut down your program while preserving its current state so that you can restart the program later.
The simplest way to cut power to the software is by using an external relay. An external relay contains two terminals: one for controlling whether or not there is power, and one that connects directly to either VCC or GND on your board depending on how it is wired. By connecting these two terminals together with a switch, you can control when your program is powered on and off.
7) Designate a kill switch in your sketch
If you want to be able to quickly stop your software from running a sketch, you can designate a kill switch in your code. This is typically done by connecting a physical button or switch to the program that, when activated, will cause the device to execute a specific command.
You can design a kill switch for your program by adding a physical button or switch to your circuit. When this button or switch is activated, it should trigger a certain function in your code that will stop the execution of your sketch. This could be as simple as calling the exit() function or writing a conditional statement that halts the loop.
Check our articles to improve your knowledge in Arduino development:
- How to Use a Microphone with Arduino?
- How to Use an Active Buzzer with Arduino?
- How to Make an Arduino Ohm Meter?
FAQ
How to use the button to start/stop the loop?
The Arduino platform is a popular choice for developers who are interested in experimenting with microcontroller programming and hardware. One of the most common questions that new users have is how to stop an Arduino program once it has been started.
There are typically two ways to do this [3]:
- The easiest option is to use one of the physical buttons on your Arduino board, such as the reset button or the power button. Simply press this button at any time during your code to stop the loop and halt any further execution;
- Alternatively, you can also use software commands to stop your program from running. This involves using functions like while(!digitalRead(7)) {} or while(1) {} to create infinite loops that will continue running until they are manually stopped;
To stop an Arduino program using a physical button, simply press and hold the reset button or power button on your board for a few seconds. This will cause the microcontroller to reset itself and stop any further execution of your code. If you are using an Arduino Uno, you can also use the onboard power LED as a physical indicator that your code has been halted. Simply turn off the power to the board and the LED will turn off, indicating that the program has been stopped.
How to avoid using the delay function in Arduino sketches?
In most situations, millis() is a superior, non-blocking alternative to time(). Timing issues are all too common in computer programming. The Arduino function delay() delays the program for a set number of milliseconds given as a parameter [4].
How do you stop an Arduino script?
There are a number of ways to stop an Arduino script from running.
The most common method is to press the reset button on the Arduino board, which will cause the current program to stop running and restart from the beginning.
Another way to stop an Arduino program is to disconnect the power supply to the board. This will cause all programs stored on the board to be erased, so it is not recommended unless you are sure you do not need any of the programs on the board anymore.
If you want to keep your programs on the board but prevent them from running, you can disable the autorun feature in the Arduino IDE. This will prevent any programs from automatically running when you connect power to the board or upload a new program.
You can also use the kill command in the Arduino IDE to terminate a running program. This is useful if you need to stop a program stuck in an infinite loop or, otherwise, it is not responding to input.
Can I just unplug my Arduino?
Yes, you can unplug your Arduino without damaging it. The ATmega chip on the Arduino has built-in safeguards that protect it from damage if no external power is applied [5].
How do I stop an Arduino program without unplugging it?
There are a few ways to stop an Arduino program without unplugging it.
One way is to use the Serial Monitor in the Arduino IDE. You can open the Serial Monitor by clicking the icon on the toolbar or selecting Tools > Serial Monitor from the menu bar.
With the Serial Monitor open, you can send a “newline” character (ASCII code 10) to your Arduino, which will cause your program to exit.
Another way to stop an Arduino program is to press the reset button on the board. This will cause your program to restart from the beginning.
Finally, you can disconnect the power supply to your Arduino. This will cause your program to stop completely and may damage your hardware if not done carefully [6].
Useful Video: Arduino Programming Tutorials || “Soft Emergency Stop” using an Externally Triggered Interrupt
References:
- https://chipwired.com/stop-arduino-running/
- https://robotsbench.com/how-to-stop-an-arduino-program/
- https://www.instructables.com/Start-Stop-Button-Switch-With-Arduino/
- https://dzone.com/articles/arduino-using-millis-instead-of-delay
- https://arduino.stackexchange.com/questions/4769/can-i-simply-unplug-the-arduino-usb-if-serial-communication-is-active
- https://chipwired.com/stop-arduino-running/
