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1500 questions
34
votes
6 answers

How to get HTTPS on Arduino?

Put plainly: is there a way to get an HTTPS connection on the Arduino? I have been looking in to it, and I have found it is impossible with the standard library and the Ethernet shield, but is there a custom library that can do it? What about a…
TheDoctor
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33
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14 answers

Most compact method of powering Arduino from wall socket

There are a lot of methods to power an Arduino from a large range of voltages: USB cable from PC or from a phone charger or an USB hub step down converters step up converters switching power supply batteries (connected to the power jack or USB or…
vlad b.
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33
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2 answers

What are the AREF, IOREF, and the unlabeled pin next to IOREF on the Uno R3?

There are some pins on the Arduino which I haven't been able to find out anything about: IOREF AREF An unlabeled one next to IOREF What are they?
tbodt
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32
votes
2 answers

How does the Arduino handle serial buffer overflow?

How does the Arduino handle serial buffer overflow? Does it throw away the newest incoming data or the oldest? How many bytes can the buffer hold?
HighLife
31
votes
1 answer

Whats the difference between RF options (wifi, xbee, NRF24L01)

When doing RF, you have many options. Three of the most basic are in the title box WiFi Xbee NRF24L01 What are the practical differences in using them. What is the purpose of each other and the pros and cons. What would you use depending on the…
user1584421
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30
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4 answers

Is it better to use #define or const int for constants?

Arduino is an odd hybrid, where some C++ functionality is used in the embedded world—traditionally a C environment. Indeed, a lot of Arduino code is very C like though. C has traditionally used #defines for constants. There are a number of reasons…
Cybergibbons
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30
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2 answers

Arduino as USB HID

Is it possible to build a HID device (like a keyboard) using an Arduino uno? At the time being, I have button inputs on the Arduino giving outputs on the serial line. So, how can I transform my current firmware into something that can behave like a…
Stuyvenstein
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30
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4 answers

What can I do if I run out of Flash memory or SRAM?

According to the Arduino documentation, the ATmega328 has 32KB of Flash memory for the bootloader + uploaded sketch, and only 2KB SRAM for runtime data. The ATmega2560 has quite a bit more, totalling 256KB and 8KB respectively. In either case, those…
Peter Bloomfield
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30
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6 answers

How to compile, upload and monitor via the Linux command line?

Interfacing an Arduino Uno (uploading etc.) with the Arduino IDE (using the Fedora package) works fine under Fedora 21. But I rather want to use vim + make + vim-quickfix-mode etc. How can I do that? Preferably via the tools available from the…
maxschlepzig
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30
votes
5 answers

What does it take to compile Linux on Arduino, if at all possible?

Is it possible to run Linux on Arduino? If yes, what steps and limitations need to be considered? If not, what are the limitations that prevent this?
Jakub Arnold
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29
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8 answers

Are global variables evil in Arduino?

I'm relatively new at programming and many of the coding best practices I'm reading effectively state that there are very few good reasons to use a global variable (or that the best code has no globals at all). I've done my best to keep this in…
ATE-ENGE
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28
votes
7 answers

How can I get a unique ID for all my Arduino boards?

Once you have uploaded a sketch to one of your Arduino boards, it is hard to know exactly what source code led to that sketch. Indeed, you may change the source code of your sketch on your PC without updating it (in binary format) to your board. I…
jfpoilpret
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28
votes
3 answers

What is Serial.begin(9600)?

I know that this is to initialize something: Serial.begin(9600); But I want to know what it really means?
shajib0o
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27
votes
2 answers

Arduino USB Power vs External Power Supply

Why is the Arduino able to accept ~5V from the USB, but requires a min of 7V when using an external power supply?
Nyxynyx
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26
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5 answers

First time set up- permission denied to usb port- ubuntu 14.04

I just plugged my arduino in and the light is on, but the blink test failed to upload. here is my error: Arduino: 1.6.7 (Linux), Board: "Arduino/Genuino Uno" Sketch uses 1,030 bytes (3%) of program storage space. Maximum is 32,256 bytes. Global…
user18719
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