Questions tagged [arduino]

Be sure to use the Arduino Stack Exchange for questions that are more Arduino and less electronics.

55
votes
8answers
38k views

How do I go from arduino breadboard to creating a real device

My first arduino project, I have made a headlight sensor that will activate an outside light when car headlights hit it. I know I could go buy one, but where is the fun in that? Now I would like to ...
51
votes
5answers
160k views

How much current can I draw from the Arduino's pins?

What's the maximum amount of current which I can draw from each of the Arduino's pins without tripping any of the internal fuses? Is there a limit per pin as well as an overall limit for the whole ...
50
votes
7answers
83k views

How can I get my atmega328 to run for a year on batteries?

Scenario I have created a nice electronic door lock for my dorm room. It is currently an Arduino Diecimila with a servo [un]locking the door. It has a numerical keypad with 3x4 buttons and 5 LED's (2 ...
49
votes
17answers
35k views

Complete alternatives to the Arduino IDE? [closed]

I'm not that big of a fan of the official Arduino IDE (in terms of visuals), so I've started looking for nicer alternatives. However, most of the projects I've found are in alpha/beta and are ...
43
votes
6answers
101k views

Do I really need resistors when controlling LEDs with Arduino?

I'm just trying out Arduino Uno for the first time with 2 blinking LEDs on a breadboard. All the tutorials on the Internet seem to use a resistor. I do know the function of resistors, but does it ...
38
votes
6answers
9k views

Why does my circuit work on a breadboard, but not on a perfboard? I am new to soldering

I'm a total beginner when it comes to soldering, and recently I've been trying (and failing) to solder together a simple circuit I put together for a Raspberry Pi sensor. Although it works fine on ...
38
votes
6answers
155k views

What is the voltage range of a standard headphone jack from a phone?

I want to connect the output from the audio jack of an iPhone to an Arduino. What voltage range can I expect to see on the audio lines from the iPhone? I assume that turning the volume up on the ...
37
votes
10answers
48k views

Why is AVR used in Arduino?

Why is Arduino using AVR? I understand that they are the official processor but there isn't a reason the code couldn't be ported to an ARM or a Freescale architecture other than cost, right? As long ...
37
votes
5answers
131k views

How can I use a 12 V input on a digital Arduino pin?

I am creating a controller for a 12 V system using an Arduino Uno microcrontroller. For the outputs I am using a relay shield to switch the 12 V components. I have a 12 V toggle switch that turns on ...
36
votes
5answers
6k views

Why should you use two resistors in parallel on an LED?

So I was looking over the Arduino R3 schematics and noticed this little design choice: What is the reason for doing something like this? I mean it's hard to know what the designers were thinking, but ...
36
votes
2answers
27k views

Selecting a MOSFET for driving load from logic

I'm looking to drive a magnetic door lock from an Arduino. I've found a question about driving a solenoid from an Arduino, which includes a circuit that looks perfect for this kind of situtation: ...
34
votes
8answers
239k views

Saving Arduino sensor data to a text file

How can I save data retrieved from a sensor to a text file on the computer?
34
votes
4answers
7k views

I2C 3.3 to 5.0 V conversion

I'm trying to interface a 3.3V I2C device to a 5V Arduino. I don't have any problem with SCL line. I can use a simple voltage divider but I have an issue with the SDA line as this is bi-directional. ...
33
votes
10answers
19k views

Is an Arduino Uno capable of running 24/7?

I'm curious as to the reliability and durability of the Arduino Uno. Does anybody have experience in "killing" one due to excessive use? If so, how long did it take for the board to fail?
32
votes
2answers
64k views

Purpose of the diode and capacitor in this motor circuit

I'm hooking up a small DC motor to an arduino using an NPN transistor using the following diagrams I found online: The circuit works, and I'm successfully able to make the motor run. Now, I'm ...
32
votes
6answers
44k views

Embedded Programming for Beginners: Arduino or Raspberry Pi? [closed]

I'm a computer science student and I'm eager to expand my knowledge on embedded programming and electrical engineering. I've read here that using tools like the Arduino microcontroller is a good way ...
32
votes
1answer
7k views

Why does my AVR reset when I call wdt_disable() to try to turn the watchdog timer off?

I am having a problem where executing a disable watchdog sequence on an AVR ATtiny84A is actually resetting the chip even though the timer should have plenty of time left on it. This happens ...
32
votes
3answers
8k views

Why do Arduinos ship w/ 16MHz crystal instead of 20MHz?

Why do Arduino boards ship w/ 16MHz crystal instead of 20MHz? They are spec'ed for operating at 20MHz, after all. I guess there are a few advantages to running more slowly (lower power consumption, ...
30
votes
12answers
46k views

Reliability of the Arduino platform for industrial use

I'm no electrical engineer (just mechanical) but I would like to apply some of my hobbyist experience to my job and implement various automated systems in an industrial (manufacturing) environment. ...
30
votes
4answers
114k views

How to connect multiple i2c-interface devices into a single pin A4 (SDA) and A5 (SCL) on Arduino?

I want to add a real time clock module into my little project. I want to display both time and date on my existing i2c 2x16 LCD module. Both i2c-interface real time clock module and 2x16 LCD module ...
30
votes
2answers
17k views

Why do some pins have `~` signs next to their numbers?

I was looking at my Arduino Uno and I noticed that symbol by digital pins 11, 10, 9, ...
29
votes
7answers
2k views

Can I develop with the Arduino using an IDE with more features?

The simplicity of the open source Arduino IDE is great, but a bit limiting sometimes - I like to use Netbeans for instance for other work that I do. Do any plugins exist for more fully featured IDEs ...
29
votes
3answers
5k views

Arduino pin spacing

How do you get around the annoying pin spacing on the Arduino? Where pin 7 and pin 8 are not standard spacing. Why is it set up like this?
27
votes
6answers
63k views

How to drive brushless motor with Arduino?

Is it possible to drive a brushless motor directly with Arduino? Or should I revert on controlling a brushless motor ESC with PWM pulses?
27
votes
5answers
23k views

Is there anything I should watch out for with cheap “Arduino” copies?

There's a plethora of cheap Arduino copies on eBay and similar sites, usually originating from the far east, that can be had for a significant chunk less than the official boards, especially if you're ...
26
votes
15answers
25k views

Controlling 500 LEDs with PWM

I'm considering taking on a project that would involve individually addressing 500 LEDs, optimally with PWM support for each. I'm planning on using an Arduino since I already have one, but I'm open ...
25
votes
3answers
32k views

How do I extend the number of analog (input) pins available to me?

I already know how to extend the number of digital pins on an Arduino using a multiplexer. I want to increase the number of analog input channels that I have. One solution is to add another Arduino ...
24
votes
4answers
97k views

Can I use the analog pins on the Arduino for my project as digital?

I am new to using Arduino, and I have an Arduino Uno. For the projects I've done, I've only used the digital pins. I am building a small vehicle that uses stepper motors. I have run out of pins to ...
24
votes
7answers
63k views

Arduino Uno R3: Directly supply regulated 5V to 5V pin?

I'd like to use an Arduino Uno R3 battery powered a datalogger. I want do supply it directly with a Step-Up regulated 5V rechargable battery powersource at power ...
23
votes
4answers
2k views

Is it advisable to stay stick to Arduino IDE?

Is it better to move to AVR studio (or any other better alternative?) over the Arduino IDE. Feel like it's so simple and childish. I need to know the experts idea and choice..
23
votes
3answers
3k views

Is there any way to simulate a program run before burning it onto the board?

Programs may, at times, have runtime errors. These are sometimes hard to find and can easily be missed. Is there any way to test the program before actually burning it onto the board ?
22
votes
3answers
5k views

Why am I cooking MOSFETs?

I've made a very simple MOSFET LED driver that uses the PWM of an Arduino Nano to switch a MOSFET which controls the power for about 16 meters of LED strip. I am using STP16NF06 MOSFETs. I am ...
22
votes
3answers
21k views

How do I create a permanent application from something prototyped with Arduino?

Part one of a three part series on transitioning from Arduino to a plain AVR microcontroller and minimum supporting components (part two, part three) I've built up a project on my Arduino Uno to ...
22
votes
2answers
52k views

What's the difference between INPUT and INPUT_PULLUP?

On newer Arduinos, one can set pinMode to one of three states: OUTPUT,INPUT, and INPUT_PULLUP...
22
votes
3answers
9k views

Jtag debugging AVR

Can anyone advise what hardware and software is required for debugging AVR in circuit.
21
votes
10answers
5k views

Is Arduino ideal for making a HRNG (hardware random number generator)?

I'm putting together a design for a hardware random number generator that will utilize multiple sources of entropy (combined): Ambient light Ambient sound (and sound levels) Ambient temp Ambient ...
21
votes
4answers
2k views

Why do we need hardware programmers?

I use a Boarduino and a 30-row bread board to program my ATtiny. I load a not too complicated sketch called ArduinoISP (included by default now in the Arduino IDE), and suddenly I have a working ...
20
votes
8answers
78k views

Is there a way to stop servos from “shaking”?

Very simply, I am controlling servos(9g Micro Servos) based on some data read in from elsewhere. Everything works fine except that the servos will constantly "shake." That is, they vibrate back with ...
20
votes
7answers
10k views

Is it possible to use multi gigabyte DRAM modules with a microcontroller?

I have two leftover 2GB RAM modules that I removed from my MacBook Pro when doing an upgrade. I was just wondering if these were usable with, for example, an Arduino. I'd be too much of a beginner to ...
20
votes
2answers
25k views

Can Arduino be used in commercial products?

Is it legal for me to sell a product that's built with an Arduino? I know that it's open source, but does that mean I can sell my product for profit, or only for use in prototyping?
20
votes
3answers
12k views

How to water-protect my Arduino?

I am building a watering system with an Arduino. Basically it runs on a track with a hose that drips water down on plants a couple of times every day. Its outside, and water might sometimes get from ...
20
votes
2answers
38k views

Active vs Passive Buzzer

I recently borrowed an Arduino Inland Basic Starter Kit. It includes an active and passive buzzer. What is the difference? I can hear a difference in sound when I use the ...
19
votes
7answers
36k views

How many individual lights can an arduino control

I want to use a regular Arduino board to control LEDs - what is the most lights I can control individually from the board? Is there a tutorial on how to hook it up?
19
votes
8answers
10k views

How to graduate from Arduino to using a microcontroller directly?

I've been working on an Arduino project. After I get everything working using the Arduino, I would like to move to a solution that does NOT use Arduino. That is, I would like to use a microcontroller ...
19
votes
1answer
7k views

Getting a large number of (~100) digital output signals from Arduino

I would like to be able to control around 100 independent LEDs using an Arduino. The problem is that the Arduino does not have nearly enough pins that can be configured for this. What would be a way ...
19
votes
8answers
8k views

Electronic pet-door access control - RFID

Inspired by projects such as the tweeting cat door and CATaLOG [sic] I’m wanting to add some form of automated access control to our pet door to control who can go in and out, when. (Full Disclosure: ...
18
votes
5answers
2k views

I understand Arduino: now what?

Alright, I've played around enough with Arduino that I feel pretty comfortable with it. Anything done now is more learning the electronics than it is the Arduino side of it. What's the next step for ...
18
votes
3answers
133k views

Powering Arduino Nano 12volts

I know that the Arduino Nano can handle 12 volts, and it says it is recommended to power it between 7 and 12 volts. So I am wondering do I just hack together a 12 volt adapter to a Mini-B or is it ...
18
votes
4answers
10k views

Low power micro-SD card storage

We are building a low-power data logger based upon the ATmega328P, in order to make use of the Arduino boot loader and IDE, etc. Ideally power consumption should be less than 0.3mA @ 3.3V to get ...
18
votes
3answers
96k views

Using a microphone with an Arduino

EDIT: I have been investigating in this problem for quite some time. It turns out to be a way more difficult project than I thought and not something for beginners. This requires expensive hardware (...