All Questions
Tagged with variables programming
20 questions
0
votes
1
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1k
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how to "skip" one parameter of a method with a default value letting it use it's default value, but change parameters after it [closed]
lets say we have a function like this(fictional):
function1(int Z, int X, bool Y=true, int Count=10, int ID=1,bool TeaTime=false);
And I want to run this function, but I want to change all parameters,...
- 254
1
vote
1
answer
339
views
How do i improve this Code? (or how to pass a Char String into a Function to behave like a Variable)
Sorry i am a beginner and amateur when it comes to coding, can somebody help me to make the code inside the loop() less "monkey-like" by using a proper function?
I have tried a lot and at ...
- 11
3
votes
1
answer
13k
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Getting enum name from enum instance [closed]
Hello Arduino Stack Exchange,
I have an an enum instance called state:
enum States
{
SLEEP,
AWAKE,
CRAZY
} state;
States state = SLEEP;
I would like to convert the value of state to a String so ...
1
vote
1
answer
4k
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Variable declared inside void setup() is forgotten in void loop()
If I declare a variable in void setup() and try to do something with it in void loop(), it just says that the variable is undeclared. Here is the code:
#include "Servo.h"
void setup() {
...
- 11
0
votes
1
answer
972
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Global Variable does not Change when Value is set within Boolean Function
I have a boolean function which contains a string. In my main project this string is extracted from a website using an ESP8266 which is compatible with the Arduino IDE. I need to convert this string ...
1
vote
1
answer
13k
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Call by reference
I am trying to learn 'call by reference'. I want to call a function fcn1 from the main loop and pass a reference of the local variable var to the function fcn1. Next step is to call a second function ...
- 11
0
votes
1
answer
969
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Space needed for local String variable
I tried to run this code on my Arduino Uno clone (which has no function so far and is a shortend version of my programm):
String rules [16][5] ={
{"B0 B5", "", "", "cs S0", "", },
[...]
};
...
- 117
0
votes
2
answers
307
views
Conditional compilation, how to determine whether a variable has been declared?
Whilst using #if/#end constructs, how can I determine whether a specific variable has already been declared?,
e.g.,
#if [the variable "pinname" has been declared]
Serial.print(F("Pin name: "));
...
- 394
0
votes
2
answers
154
views
What is the opposite of this data operation?
If I store in an array a double-value in this format, in which format I should be able to read the same double out?
double myDouble = 12.123456;
byte myArray[] = {0x00, 0x00, 0x00, 0x00};
myArray[0] ...
- 515
0
votes
1
answer
165
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Arduino join multiple strings and numbers and then seperate them
OK, I'm working on a remote controlled robot. Both the robot and the remote use Arduino with a Bluetooth shield. The Bluetooth is working and I need to send something similar to this over Bluetooth:
...
- 240
1
vote
2
answers
1k
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How to count the number of times a changing variable reaches a peak value
I am recording a varying distance with an Ultrasonic sensor and Arduino but my problem is I want to display the number of times this variable reaches peak (at an instance the value will be increasing ...
- 11
0
votes
1
answer
1k
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Global Variable not able to be accessed in function?
I am trying to compile an Arduino program that takes analog input. However, when I declare multiple global variables, it often will not compile and because it throws an error that the variables aren't ...
- 121
6
votes
1
answer
3k
views
What are the benfits of global variables over static class members?
On an embedded system we use global variables often to keep dynamic memory consumption on heap and stack low. But global variables are also considered bad programming practice if they aren't used in a ...
- 577
5
votes
3
answers
36k
views
Convert long to char array and back
I'm trying to store a state in my data logger. I can read/write fine to SD, but I can't wrap my head around reading/writing a long value correctly - I've build it down to converting it to char array ...
- 155
0
votes
3
answers
2k
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Help with a function that accepts different parameter types
I'm trying to create a function that prints out an XML tag with a value. I have the code below, but kind of stuck. I'd like to be able to call the function, and pass a value that could be a float, int,...
- 3