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1500 questions
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very lightweight low power microcontroller with memory?

I have build a couple of projects using arduino. For a new project I want to log skin surface temperature vs. time (just perhaps a few times per day) and possibly other easy to obtain info such as voltage. I need to make everything as small and…
Shara
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What are the SVG pins for on the SainSmart Uno clone?

I bought a SainSmart clone board which is compatible with the Arduino Uno R3. Alongside each of the standard IO pins, there is a row of 3 additional pins (male). They are arranged in columns, marked S, V, and G. They can be seen on this image: Most…
Peter Bloomfield
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nRF24L01 pipe question

I am looking through the example code found here. I know there are 6 pipes that the nRF24L01 module can use but I've been searching the internet for the address designations and have been able to find nothing. More specifically on line 37, is there…
Alex
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What will happen when I use an invalid pin number?

Related to: What happens if there is a runtime error? This question is similar to the one above, however this is an alternate situation: int pin = 999; pinMode(pin, OUTPUT); digitalWrite(pin, HIGH); What would happen in this instance? The…
Anonymous Penguin
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Is it possible to program an Arduino Pro Mini using an Arduino Uno R3?

I've recently received an Arduino Pro Mini as a gift, and I don't have an external USB programmer to program the Pro Mini. However, I do own an Arduino Uno R3, and I think it would be possible because they both have the same clock speed and…
slippery
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Turning all LEDs on (FAST.LED)

In Fast.Led lib for arduino there is a code to turn off all leds FastLED.clear (); Is there also a shortcut to turn all LEDs ON, and with a specific color
Niles
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Sending colours to vga monitor

I'm looking for a simple way to send a signal from my arduino to a vga monitor. What would be the easiest method, and what components would be needed? I don't need to display an image, just a solid colour.
Terry
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Why the need to use the volatile keyword on global variables when handling interrupts in Arduino?

I am familiar with the keyword Volatile being used to declare variables that are shared among multiple threads on a software application (basically on a multithreaded application). But why do I need to declare a variable as Volatile when running the…
T555
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Why is there a clock in my arduino?

Of course I know it is usefull to control the time of a delay, but any other use? With a 16Mhz clock, each line of my program will take 1/16000000 second, right? even a very very big line will only take 1/16000000 of a second ? With a 8MHz clock,…
n0tis
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Programming many Arduinos simultaneously with a wireless broadcast

I will have many microcontroller-based devices which will be independent from each other, but all will run the same program. I would like to upload a program to all of them at the same time with a wireless broadcast. Ideally the user would plug in…
MGA
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ESP8266 Analog read interferes with wifi?

Short version: I have a program that connects my ESP8266 to WIFI so I can control a relay connected to it over the internet or a button. I also have a sensor for my door. This software works perfectly, if I add a light dependent resistor to it…
JanG
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Re-use smartphone/tablets parts like a camera

For learning and hacking purposes, I plan to study and use parts from smartphones and tablets like Galaxy or iPhone. They are really efficient and pretty cheap... Did anybody do this before? If yes, can anybody tell me what kind of connector is this…
Charaf
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ERROR: Timed out waiting for Arduino 101 - anything I can do?

I just received an Arduino 101 so I did the following in a wave of excitement... Connected the USB cable between it and my Macbook Pro Started the Arduino IDE version 1.6.7 Wrote a little bit of code Selected Tools | Boards | Boards Manager... and…
kmp
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Is volatile needed when variable is accessed from > 1 ISRs, but not shared outside ISRs?

It's clearly documented that when global data is shared with an ISR and the main program, the data needs to be declared volatile in order to guarantee memory visibility (and that only suffices for 1-byte data; anything bigger needs special…
Joonas Pulakka
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Arduino ADC Reference Voltage if it is Battery Powered

I am looking to possibly monitor battery power to the Arduino using its ADC. This is fairly straight forward and simple (especially if using the Arduino API); however, if the battery is powering the Arduino and is unregulated externally, won't the…
ryeager
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