Frequently Asked Questions
Community Wiki answers to questions people keep asking over and over again.
Feel free to mark questions as duplicates of ones in this tag.
Questions tagged [faq]
7 questions
184
votes
21 answers
"avrdude: stk500_getsync(): not in sync: resp=0x00," aka Some Dude Named Avr Won't Let Me Upload My Program
I made an awesome program the other day, and I wanted to upload it to my Arduino. After clicking the upload button, some mean dude named avr came along and stopped me, saying:
avrdude: stk500_getsync(): not in sync: resp=0x00
All I want to do is…
The Guy with The Hat
- 5,292
- 7
- 30
- 51
4
votes
2 answers
Why do people complain when I call my functions voids?
I have posted questions about "my void loop" or "my void setup" and people complain that they aren't really voids. But they are! See this example code:
void setup() {
pinMode(13, OUTPUT);
}
void loop() {
digitalWrite(13, HIGH); // turn the…
Nick Gammon
- 38,901
- 13
- 69
- 125
1
vote
1 answer
Why my ISR is giving impossible values?
I have a very simple ISR:
const uint32_t PATTERN_A = 0xFF00FF00;
const uint32_t PATTERN_B = 0x00FF00FF;
volatile uint32_t count = 0;
volatile uint32_t toggle = PATTERN_A;
// My ISR
void callback()
{
count++;
toggle = (count % 2) ?…
user31481
1
vote
3 answers
Analog input draws current when Arduino is turned off
I am using a Arduino Pro Micro from SparkFun (similar to Arduino Leonardo, cpu: Atmega 32u4). It has a analog input: A0, which I use to keep track of the battery voltage in my battery powered project (via analogRead).
I found out that the red LED on…
salami738
- 13
- 4
1
vote
3 answers
My Arduino isn't showing up on my computer. What should I do?
You have your spangly new Arduino board, you've installed the software, and you plug it in. Nothing happens. Diagnosing problems may be a little tricky for the beginner, so what hoops should you go through to try and work out where the problem is…
Majenko
- 105,851
- 5
- 82
- 139
0
votes
3 answers
I have made a Nano send 4 pot values to an Uno please help with code
Happy New Year!
So I have made a Nano send 4 pot values to an Arduino Uno over serial but I have a problem: I don't know how to separate these values. Here's the code:
Master:
int Pot = A0;
int Pot2 = A1;
int Pot3 = A2;
int Pot4 =…
Imanoobdotcom
- 11
- 2
0
votes
4 answers
Strange compiler error (Segmentation Fault)
You're getting a compiler error. It happens in strange parts of code that really shouldn't be having a problem. The error looks something like:
C:\Program…
Majenko
- 105,851
- 5
- 82
- 139