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2 answers

Are function pointer assignments atomic in Arduino?

The following snippets are from TimerOne library source code: // TimerOne.h: void (*isrCallback)(); // TimerOne.cpp: ISR(TIMER1_OVF_vect) // interrupt service routine that wraps a user defined function supplied by attachInterrupt { …
Joonas Pulakka
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What is the cheapest way to add wifi to Arduino?

I am trying to find some sort of wifi adapter for Arduino, it needs to be as small as possible (not a shield) and as cheap as possible. So far I can only seem to find shields that cost about £10+ but I figured that if you can get a replacement wifi…
connersz
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11
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4 answers

How do I know if a board fits my requirements?

I'm new to Arduino and I saw on their website that there are many different kinds of boards. What are the differences, or to be more specific, how would I know which board meets my requirements? I understand that the shields can be connected to the…
Elior
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Why does the Arduino Due have a native and USB programming port?

According to the schematics, the Arduino Due has two USB inputs: Native Programming Why is this? And when would I use the different ports?
poseid
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11
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What I should be aware before I touch my Arduino?

Before you start to mess with a computer there are basic guidelines to be aware of, such as turn the power off and watch out for static electricity. What guidelines should I be aware of when I work with an Arduino board if I don't want to harm…
totymedli
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11
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Getting the contacts/ storing contacts to SIM card

I have the GSM shield and is there any ways to get the stored contacts on the SIM card? It seems that the GSM library does not support writing data onto/ reading data from the SIM card? My aim is to store the SIM card's phone number and some…
MW_hk
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11
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4 answers

How do I use RFID-RC522 with an Arduino?

I am working on a project for my local Makerspace, we have limited budget so I was hoping to use the RFID-RC522 el'cheap'o RFID/NFC readers on eBay, I received a couple of SPI based boards, they work, however the code examples for them are…
unknowndomain
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11
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4 answers

Choosing wireless tech for lowest possible lag

I am drafting a pub quiz project, where the Referee gives a signal and multiple players push their buttons. The first to push wins the right to give an answer. I want all buttons (referee's + X players) to be wireless. Since the best quiz players…
Brian G.
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11
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2 answers

Understanding the compilation/linking/upload process (so I don't have to use the IDE)

I have started to play with and arduino UNO quite recently (without any prior experience with micro-controllers). I would like to use emacs instead of the IDE, and I'd also like to know what the IDE does under the hood, in order to be able to write…
Ash
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11
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Increase PWM bit resolution

I would like to increase the PWM bit resolution of the Arduino Uno. At this moment it is 8-bit which I consider too low. Is this possible without losing the ability of interrupts and delays? Koen EDIT This setup delivers a 16-bit resultion void…
KoenR
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11
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How can I communicate Raspberry Pi and Arduino (in both ways) using a 10-15m distance wires?

I am starting a personal project of home automation and I have a raspberry pi and an arduino Uno board. I want communicate raspberry pi and my arduino where my raspberry should be able to write and read signals to and from arduino. The distance…
thiagoh
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11
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1 answer

Extend battery life with a power-controlling microcontroller?

This article describes a method to extend the battery life: use a low-power controller to switch on the Arduino only when needed. The author states that this method uses considerably less power than using Arduino's sleep mode. Are there downsides to…
tuomassalo
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11
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4 answers

What is the best way to define an I/O pin?

I read definitions like const int ledPin = 9; and also #define ledPin 9 I know that a definition like int ledPin = 9; is a bad practice if you're not going to change it (which you usually won't), though I've see this several times in Arduino…
Joris Groosman
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10
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Writing First Library - Serial Stream Object

I have done quite a few projects with Arduino, but have never done more than a "Hello World" in C. I am writing my first library, and a lot of the object oriented stuff is going over my head. Anyway, my library is working as it is supposed to, I…
ahalekelly
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10
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Emulating 1-wire device(s)

What I want to do is make a ATTiny IC become a slave on the 1-wire bus, with its own S/N and command list for its specific functions. What I want to know is if I can use the one wire library from the arduino site to send data as a slave. For…
RSM
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