Newest Questions
25,033 questions
26
votes
3
answers
6k
views
What happens to the Arduino if you don't use a resistor with an LED?
Making a blinking light seems to be one of the most common beginner projects with Arduino. A typical approach is to connect an LED + resistor (in series) to an IO pin, and connect the other end to ...
- 11k
14
votes
6
answers
18k
views
Sending Large Amounts of Serial Data
So in the fields of robotics sometimes you need multiple boards and or computers linked together to share information or save statistical data. Currently I need to send a few different variables over ...
- 511
0
votes
2
answers
7k
views
When to use different variable types? [closed]
There are several different types in the Arduino programming language. They each have different applications that can use up the limited RAM in the Arduino. When should i use each?
- 3,509
10
votes
4
answers
9k
views
How to really shrink a sketch
I want to make a sketch that is as small as possible, for test purposes. The problem is, when i compile the BareMinimum sketch (with an empty setup and loop), i get 466 bytes for the Uno and a ...
- 3,509
17
votes
6
answers
15k
views
What happens if there is a runtime error?
What happens if there is a runtime error in a program? Will execution of the program just stop? Is there some way I can get the Arduino to tell me what the error is?
- 5,302
18
votes
2
answers
27k
views
What happens when I call exit() from my program?
In either of setup or loop, if I were to add an exit(0) call, where would control be passed to? What would the next state of the microcontroller be? Would it stop execution and power down?
I am using ...
- 3,847
16
votes
2
answers
9k
views
Button state changing randomly
I have a push button wired to my Arduino but it seems to be triggering randomly.
I have one pin of the button connected to pin 2 on the arduino and the other connected to ground.
void setup() {
...
- 7,565
14
votes
5
answers
5k
views
How to connect two Arduino without shields?
I'm planning an Arduino system that consists of several Arduino boards. The maximum distance between the boards is about 50 meters. I want to send basic data between these, like short strings or ...
- 2,929
62
votes
7
answers
232k
views
Is there any way to download a sketch from an Arduino?
I made a sketch, but then I lost it. However, I uploaded it to the Arduino before losing it. Is there any way I can get it back?
- 5,302
55
votes
12
answers
279k
views
How do I print multiple variables in a string?
Say I have some variables that I want to print out to the terminal, what's the easiest way to print them in a string?
Currently I do something like this:
Serial.print("Var 1:");Serial.println(var1);
...
- 7,565
8
votes
4
answers
4k
views
Is there a semi-permanent way to attach wires to the Nano?
At least for prototyping, is there a semi-permanent way to attach wires to the Nano posts?
And yes, usually the Nano is hanging in free space by its wires (yes I know, quick and dirty, should be using ...
- 339
23
votes
2
answers
19k
views
Why can't I declare a class in another tab in Arduino IDE?
I wanted to move some of my code out into a second tab in the Arduino IDE, to keep things better organised. At first, I only tried moving a function, and it seemed to work fine. I could call the ...
- 11k
12
votes
3
answers
29k
views
How do I use I2C devices with Arduino?
I have a few useful I2C components, such as a 16-bit port expander (MCP23017), which I'd like to use in various projects.
What do I need to do to make these work with Arduino? Will it work with any ...
- 11k
6
votes
1
answer
1k
views
Connecting breakout board to Arduino with UART
I'm using a DigiX (Arduino Due based 3.3V) board to connect to a GPRS/GSM SIM908 breakout board. The SIM908 EVB board has the following pins on its RS232:
I've got all three UART TX lines hooked up ...
- 175
22
votes
3
answers
196k
views
How to check my Arduino board is working or dead?
When you have a board in your hand but you don't know is it working or not, how to verify if it's working or dead?
- 1,407