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1500 questions
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3 answers

PROGMEM: do I have to copy data from flash to RAM for reading?

I have got some difficulties understanding the memory management. Arduino documentation says, it is possible to keep constants like strings or whatever I don't want to change during runtime in program memory. I think of it as embedded somewhere in…
Ariser
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Only 2 decimal places in printed float

There was a similar thread before but it didn't solve my problem. I had an issue with sending GPS data, which is float, and I couldn't receive the float with the same amount of significant figures as I was sending. I always received a number with 2…
Anthropomorphous Dodecahedron
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How can a 5v Uno talk to a 3.3v Due?

I currently have an Uno (which operates at 5v), and I'm looking at buying a Due (which only operates at 3.3v). I'd like to make them communicate via Serial or SPI or similar, but presumably connecting them directly isn't an option (I guess the Due's…
Peter Bloomfield
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9
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5 answers

How can an Arduino output a specific (i.e. 56 kHz) carrier frequency?

I'm working on a free space optics project to send data wirelessly between two points. To accomplish this I'm using an IR LED connected to an Arduino Uno that pulses with a 56 kHz carrier frequency for the transmitter and a second Arduino with a…
jlbnjmn
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9
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7 answers

What is commonly done to stop a servo after reaching desired position?

When I started Arduino, I did not expect that everything must be contained in an infinite loop. I thought I could just write something like: motor start -> motor stop. But in actuality, what I get is motor start -> motor stop -> motor start -> ...…
Fraïssé
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2 answers

Difference between SoftwareSerial and Serial

From the sample code #include SoftwareSerial mySerial(10, 11); // RX, TX void setup() { // Open serial communications and wait for port to open: Serial.begin(57600); while (!Serial) { ; // wait for serial port to…
Siddharth
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9
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2 answers

Why does an Arduino UNO need two GND ports?

I have really bad eyesight, so whenever I plug in the power wire and the GND wire I always double check if I'm actually plugging in to the power port not one of the two GND ports. Why does an Arduino UNO have two GND ports, and for what application…
Fraïssé
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6 answers

Very long delay() possible?

I'm trying to make an opening and closing little door that should open or close every 12 hours. I was wondering if I could just make a small looping script with a delay() for 12 hours, delay(43 200 000 000); I guess? However, I have no idea if…
Fred Pannekoek
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Arduino Micro vs. Pro Micro

What are the differences between the Arduino Micro and Pro Micro?
user33613
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4 answers

Explain what is meant by "Arduino core"

What is an "Arduino core"? Are there many different "Arduino cores"? such as a core that applies to LCD displays, another core that applies to servos, etc.?
martymarty
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If the USB gives 5v, how can the Arduino supply 5v to the 5v pin? (And another question)

I must not of understood something. Online, I've heard that the Arduino uses 9v typically (average), and that USB's in general supply 5v@500mA. If this is true: How can the Arduino even POWER ITSELF with the 5v USB? I've heard the minimum is…
Blake
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In ESP-12E NodeMCU, what's the pin number of A0?

In ESP-12E NodeMCU, all digital pins can be called with a number. Here is the list: static const uint8_t D0 = 16; static const uint8_t D1 = 5; static const uint8_t D2 = 4; static const uint8_t D3 = 0; static const uint8_t D4 = 2; static…
pfernandez
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3 answers

Multiple independent LED patterns

I have an problem, which at first thoughts (and being new to Arduino) I though was a perfect application for an Arduino. However, after trying and failing to implement it I am doubting myself! Simply - I need to control many LEDs independently, many…
Nickos
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How to use breakpoints for debugging

Breakpoints are a great way to see how the compiler runs to your code. Now my question is, is there a possibility to use breakpoints when you debug your code?
H. Pauwelyn
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9
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4 answers

Turn Arduino on with timer every 24h

I'm currently working on an Arduino project that sends the charge of my car battery once a day via an ESP8266 to me. During the winter I don't drive my car, and I would like to get informed when the battery drops beyond a critical value, so I can…
Dirk Pitt
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