Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [arduino-uno]

232 questions
10
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5 answers

Did I design my LED circuit correctly?

For my wedding I'm making some letters which I would like to provide with some LEDs. To have the full "I made this myself" experience, I gave myself a course on electrical engineering (google ftw), and started designing a circuit that could work…
Guinn
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8
votes
5 answers

MOSFET overheating in Arduino heating pad project

I am very new to electronics and working with Arduinos, I am learning a lot and would appreciate any help. I am making a heating pad system for a high-altitude weather balloon science experiment. The circuit (sorry for the hand-drawn circuit…
DRAGONiaj Pax
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6
votes
9 answers

How can I connect multiple potentiometers (~20) to my Arduino without having to have 20 analogue pins?

I'm trying to build a MIDI controller and I'm looking for a clever way of using 20 potentiometers without having to have 20 analogue ports on the Arduino. So far all the functionality I need is for every potentiometer to print its current value on…
Michelangelo Prisciano
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6
votes
2 answers

200 mA output from the Arduino digital output

200mA and 0.2V are needed to turn on a mid-IR LED. Given that the output current of each digital pin in Arduino UNO is 40mA, is sufficient current provided by simultaneously connecting 5 pins to the LED? Due to the current limiting by the…
Bright Day
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6
votes
4 answers

Can a USB port passively 'listen only'?

I have a small dedicated controller built around an Arduino that accepts commands from a PC over USB (serial). The communication is one-way -- the controller never sends data back to the PC. Now I need to extend the controller to handle more duties,…
Jim Mack
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6
votes
1 answer

Advice for this P-Channel MOSFET Power Source Selector

I know there are already questions and answers about P-Channel MOSFETs and power source selection, but I still find myself pretty confused, as many of those are more complex than my circuit or simply connected differently. I'll lay out my design and…
Andrew M.
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5
votes
0 answers

Trying to replicate the behavior of an smartcard without sucess. What I am doing wrong?

Background: I am a software engineer and I am starting to research security hardware in my free time. The one I am starting with are contact smartcards, which are defined by the ISO 7816 standard. I managed to create a hardware to probe into the…
Filipe Rodrigues
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5
votes
4 answers

void loop executes even when the while loop inside is true in arduino

I made a simple mobile application to send LED_ON or LED_OFF when a button is clicked. In the below code the while loop is not fully completed while execution but the controller is going to the void loop() and continuing from there. char…
ganesh vicky
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4
votes
4 answers

Output from TD100 with instrumentation amplifier not as expected

I've been having trouble with my TD100 circuit for a few days now and I cannot understand why the output isn't as I expect. This is the process: simulate this circuit – Schematic created using CircuitLab I get around 3.105V at the output for room…
TGS
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4
votes
2 answers

Will this photodiode circuit work?

I'm relatively new to electronics. I've seen a few circuits online, I just wanted to check that this schematic I drawn would work. The purpose of the photodiode will hopefully be to read a modulated LED signal. Is the choice of Op-Amp suitable to…
DaveS
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3
votes
0 answers

Running a 12V motor on 9V battery and arduino and matlab implementation

I have a DC geared motor rated at 12V and 60 rpm . It has a quadrature encoder with 700 PPR. I connected it directly to a 9V battery (almost new) and wished to measure the rpm of that motor. To find the nature of the pulses generated by the encoder,…
Helix xxx
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3
votes
1 answer

Oxygen sensor voltage changes when machine is powered on. Interference?

I built an Arduino Uno based control panel for an altitude training machine, which connects to an oxygen sensor. The value is amplified by an instrumentation amp (INA122P) and read into the analog input of the Ardiuno, which then decides whether to…
Daniel Dowling
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3
votes
1 answer

ATmega328P development board not working

I've made a development board for ATmega328P like Arduino Uno. Fig. 1 - schematic Fig. 2 - bottom layer Fig. 3 - top layer I am able to upload the code using FTDI chip (I've used the chip which has boot loader in it). However the code is not…
Anil Suha
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3
votes
1 answer

How To Reassign The MISO Pin?

So I have a PCB with an LCD hooked up along with a 595 shift register. Unfortunately, when I designed the board I didn't realize that the LCD library used SPI, which on the Arduino Uno is pins 13-10. Therefore, the system overrides the pin 12 for…
mr-matt
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2
votes
1 answer

GP2Y0A21YK0F Sharp IR sensor not counting below a certain distance threshold

I'm building a self-navigating robot that uses IR sensor (GP2Y0A21YK0F model) with Arduino to navigate through a terrain, however during testing phase when I put my hand closer than 7cm it bugs and doesn't detect if anything can be closer than that…
melonade
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