Questions tagged [arduino-uno]

The Arduino Uno is the most common of the Arduino boards. It is based on the ATmega328P microcontroller.

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1answer
4k views

Do I need to use a resistor if I am using a potentiometer to control an LED's brightness?

I am currently tinkering with an arduino, and am using a potentiometer to change the brightness of an LED. I understand that usually, a resistor is added to the circuit to limit the current flowing ...
7
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1answer
3k views

Why does increasing resistance make a capacitive sensor more sensitive?

From the Capacitive Sensor Page on the Arduino website, it states the following: The capacitiveSensor method toggles a microcontroller send pin to a new state and then waits for the receive pin to ...
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1answer
7k views

How to use String.substring?

I have the following code in which requestLine is always empty and I can't figure out why. request contains a raw HTTP request, and I want to get the first line of the request which contains the ...
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1answer
150 views

How do I avoid this error trying to connect arduino to pc with linux fedora 20

I used Arduino successfully on my old Linux Fedora 12 system. Now I have a brand new PC with Fedora 20, and have today installed Arduino on it. In my first attempt to use it I typed Arduino as follows ...
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2answers
6k views

bootloader uploading into Atmega328

Here is mine circuit. Intially i used arduino UNO directly for programming. Now i am Using atmega 328 IC for programming. I am trying to connect 32 hall sensor via Mux circut. I wanted to How to ...
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2answers
2k views

Error while connecting Arduino to Macbook: “serial port already in use. try quitting any programs that may be using it”

I'm trying to connect to my Arduino board through a macbook pro with mac os x 10.9.3 installed. I'm following the instructions from the arduino guide and in the connection section: " Connect the ...
4
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3answers
1k views

Significance of the numbers used in the manual

i just bought the starter kit and am currently working my way through the examples in the book when i came across some numbers used in the manual that seems a little too specific. For example, in ...
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2answers
223 views

help with input in a Simon arduino uno game

I' making a Simon game with the arduino uno. I know something is wrong with the inputs but i don't know why or how to fix it. The problem is the program takes an input and says it is correct no ...
3
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1answer
3k views

Reset fuses on atmega328p using Arduino

I bought a few atmega328p chips but unfortunately they came with the Arduino bootloader and they are set to use the external clock. I want to reset their fuses using avrdude so I can use the internal ...
0
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2answers
485 views

Stacking shields without headers

In the project I am working on, I have a limited space with which I can work. I am using an Arduino Uno with 2 Adafruit motor shields, and when I stack them using normal, female stacking headers it is ...
2
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0answers
682 views

Negative value conversion for modbus slave

I have an analog sensor which reads values 0-5v, -75 degrees to 75 degrees. Now I have converted to +75 degrees and -75 degrees format depend on the voltage. From 2.5v to 5v data is read properly (i....
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1answer
938 views

Analog average sample wind speed sensor

I have wind speed sensor that can measure max speed upto 30 m/s with analog out put 0-5v. I have simple code calling from the loop. When I put the wind speed average code, the web server is not ...
2
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1answer
914 views

Connect to more than one Arduino with Adobe AIR

I am using the arduinconnector ANE to connect to an arduino baord in an AIR application. https://code.google.com/p/as3-arduino-connector/ Can anyone tell me if its possible to connect to more than 1 ...
3
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1answer
437 views

Setting time frame in Arduino Uno

I have built the circuit below using mux ICs. In a particular interval the respective selector pins get selected and analog signal from hall sensors are read and give a particular analog value out. ...
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0answers
40 views

How to communicate arduino with Matlab [duplicate]

I have been working on a project which deals with analysing data from sensors to matlab. How do i establish this communication. Please help me
3
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1answer
871 views

Timer1 stops firing

I am trying to use interrupts to play notes on a speaker. Timer2 works fine, but after about 15 seconds, Timer1 stops firing for about 5 seconds, and then it comes back on. If I keep running the ...
3
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1answer
683 views

To connect a simple toy circuit and trigger with an arduino?

I have a small circuit from a toy sword that has an LED and a small speaker. It was powered by a couple of small coin cells. I am trying to figure out how to connect it to my Arduino so I can trigger ...
4
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1answer
606 views

Can a PC connect to an Arduino for serial communication without installing the entire dev kit?

I'd like to send a prototype board to a friend pre-programmed and wired. Ideally they should just need to plug in the USB and connect to it over a serial COM port. With another laptop I used for ...
1
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1answer
935 views

Unable to read text file from server

I saw the Web client Example , In the example, the server connection is initialized in setup(). But I want the server to update the text file every time. So, I need the server connection to be in ...
0
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1answer
754 views

DC-DC converter with Arduino not working

I've got a program running on the Arduino that is supposed to turn on and off a pump. currently, I am outputting the reads of the components that need to be read and it shows when the port (port 13) ...
8
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2answers
4k views

Use Higher Resistance Than Instructed in a Circuit

I'm following the "Get Started with Arduino" Guidebook, and I'm at the part where pulse width modulation (PWM) is discussed. The instructions say to create a simple circuit with a breadboard, red ...
-2
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1answer
1k views

Cheapest way to connect android device to arduino wirelessly

I'm building a simple RC car which I want to control using android phone. The phone has bluetooth and Wi-Fi. My questions is what will be the cheapest way to connect the two devices at about 50-120m ...
7
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2answers
2k views

Convert a Bitstring into an integer value

I have got a String filled up with 0 and 1 and would like to get an Integer out of it: String bitString = ""; int Number; int tmp; bitString = ""; for (i=1;i<=10;i++) { tmp= analogRead (...
0
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1answer
2k views

Adafruit motor shield + Adafruit stepper not working

I have the Adafruit Motor Shield V2 and an Adafruit stepper motor. I have not soldered the shield onto the Arduino (which is an Uno) yet because I don't want to make anything permanent yet. I have the ...
5
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1answer
2k views

How to make XBee module interrupt/wake arduino

What I am trying to do is, to have arduino in low power mode and waking up only when a packet is received and is available to be read from the buffer. A scenario : Zigbee XBee module is not ...
13
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4answers
27k views

What's the deal with Uno's pin 13 LED?

(I have a Sparkfun RedBoard, but this question seems to apply to R3 Unos and Uno-compatible boards.) As I was building the first circuit in my SIK guidebook (add a resistor, LED, hook it up and make ...
-2
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1answer
444 views

Receive SMS example gives me a garbage values

When I run my Receive SMS example code, By default every time I get the same thing.I am trying to send sms to my sim card present in the Arduino GSM shield. I don't want this message. How to solve ...
1
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1answer
352 views

digital pin's current limit, ohm's law and DC motor

A digital pin's output voltage on an UNO board is 5V, which is equal to the output from the VCC. I read that the DC current limits of those pins are 40mA and 200mA respectively, and that a higher ...
5
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1answer
367 views

Is the Sparkfun RedBoard pre-loaded with a blink sketch?

As soon as I plugged my brand new RedBoard (Sparkfun's Uno) into my computer, I saw the onboard LED (for pin 13) blink on and off every 1 second. This was before I even sent the first demo sketch to ...
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3answers
4k views

client.connect() fails except the first time

I am communicating with the Web server's database via Arduino GSM shield + GPRS connectivity void loop() { if (client.connect(server, port)) { ....... } else { ...
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2answers
569 views

Figuring out some numbers for a mini pump

I'm just now getting into electronics (I don't know why I waited so long) and I'm just figuring out some stuff. I picked up an Arduino kit from Vilros.com and a few other parts for my project. I'm ...
3
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1answer
794 views

Arduino Uno + Ardumoto + BT robot works from USB but not from baterries

My Arduino UNO board is part of a small robot that works when connected to the laptop by USB but it does not when plugged to the batteries. The baterries plug seems okay, it outputs 7.8 V. My UNO is ...
2
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2answers
627 views

Is it possible to transmit Longitude and Latitude via RF433MHz?

I want to make a drone project, and to that I will use arduino as the platform. My plane is to use a Play Station controller to control the Drone in the air. In addition to that I want to connect a ...
2
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1answer
385 views

Larger NFC antenna? [closed]

Goal: I would like to be able to transfer some information to an Arduino Uno board via an NFC shield/antenna. The situation requires that the NFC tag may potentially hit anywhere within a circular ...
1
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0answers
153 views

is it possible to backup an uploaded program? [duplicate]

I have a cute robot built on Arduino Uno and Ardumoto, and I am trying to reverse engineer it first, and to add some new sensors afterwards. I am stuck at how to deal with its program. I don't have ...
11
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3answers
5k views

High precision timing on Arduino for serial communication

I am using an Arduino Uno to send time and voltage information over the serial port to Python to plot. However the interval timings between successive time stamps appears to be increasing over time, ...
1
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1answer
5k views

How to control Keyboard inputs using arduino(serial monitor) and python keyboard libraries?

I am able to control my monitor and most other applications by giving serial input to python through arduino. Arduino code: void setup() { pinMode(2, INPUT); pinMode(3, INPUT); pinMode(4, ...
3
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2answers
892 views

How do I use the timers on an Arduino Uno R3?

I want to make a simple circuit which returns the time/delay between two, consecutive loud sounds (i.e, a mic reading of ~600) coming from a speaker. I have set up and ADMP 401 microphone for this ...
2
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2answers
848 views

Matching Baud Rates

So I am working on speeding up a nixie tube speedometer, in this question: , but this brought up another question. Would having matching baud rates for multiple external devices speed up processes. ...
4
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1answer
3k views

Check contents of buffer after serial read

I would like to test the contents of data received over a serial connection. In my loop() I store the data in bffr; and afterwards I would like to test to see if there are some predefined words in it. ...
3
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1answer
120 views

Pull Chain Switch

I'm a bit new to electronics/Arduino projects, so am looking for some help on some wiring needed for a project involving this Pull Chain: http://proto-pic.co.uk/pull-chain-switch/ The chain works ...
2
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1answer
3k views

Interference at digital input (UNO) [duplicate]

I was trying out a basic button tutorial on my new Arduino UNO. But for some reason, the Arduino was detecting the button as on (pressed) even when it was off (unpressed). After some experimentation, ...
2
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1answer
1k views

ArduinoUno+LcdKeypad+ArduinoWifi=Pins Problems

Is it possible to connect these two shields to my Arduino Uno? After a research on the internet, I discovered that they use some of the same pins. Even so, is it still possible for me to connect the ...
0
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1answer
135 views

Unrecognizable Message From PROGMEM char*

I'm using a PROGMEM char* to store a massive array. When I try to print a certain part of the array, the message comes out mangled. How do I fix this? The output should be "Poliwag", but it comes out ...
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2answers
1k views

How to connect a 2 cell LiPo batter to Arduino Motor Shield?

I am trying to connect a 2 cell 7.4 volt LiPo battery into my motor shield. I am a beginner at robotics so I am not sure if I just connect the battery, via a connector of some sort, into the motor ...
2
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1answer
2k views

Why my Arduino Uno R3 doesn't work with a recompiled optiboot with BAUD_RATE=57600

This is a follow on question from How to reduce serial speed on Arduino bootloader (optiboot) and on the IDE? I did manage recompile optiboot bootloader to work at 57600 bps and uploaded it to a ...
6
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2answers
10k views

“Broken Pipe” when uploading to Arduino UNO

I just got my Arduino UNO and I'm trying to upload the blink example but the upload fails with ioctl("TIOCMSET"): Broken pipe ioctl("TIOCMSET"): Broken pipe avrdude: stk500_recv(): programmer is not ...
4
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1answer
346 views

Arduino Lego Robot

I'm currently developing a Lego Robot, the mindstorm series to be specific. I want to replace the lego NXT brick with an arduino, maybe an intel galileo in the future. How do I establish connections ...
3
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1answer
2k views

Arduino Uno R3 ISR does not work on pin 2?

I have an Arduino Uno R3. I have a paddlewheel waterspeed sensor that I use on an ISR on pin 2. The power supply is approximately 8v stepped down to 4.92v with a circuit yanked from the phone charger. ...
6
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4answers
3k views

Can the Arduino Uno become an AVR programmer and use the ICSP header to program the target board

The Arduino Uno has an ICSP header that I imagine is for programming the board using a separate ICSP programmer. That is, its ICSP header turn the board into a target. Can one use that same ICSP to ...