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Questions tagged [voltage]

Voltage is the difference in electric potential between two points of an electric circuit, measured in Volts (V). Voltage can be constant (DC) or varying (AC).

6
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3answers
28k views

NodeMCU - Vin pin as 5V output?

I know that Vin can be used to power the board but have also been reading that it can be used as a 5V output. Is it possible to assign Vin as an output as I would any other GPIO? If I want to power ...
5
votes
1answer
141 views

Why is my Analog Input channel adding voltage to my signal?

EDIT: Here are the links to the sensor spec sheet (http://www.omega.com/temperature/pdf/HX71.pdf) and manual (http://www.omega.com/Manuals/manualpdf/M4543.pdf) for your reference. I'm using a ...
4
votes
3answers
3k views

How to know positive and negative in breadboard

I have this breadboard, and there is no indication on it about what is positive/negative on it. In comparison, this other breadboard (pic from the internet) DOES have indications: Can anyone give ...
4
votes
1answer
355 views

Measuring voltage from -12 to +12 VDC

I'm making a -12 to +12V DC regulated power supply, on which I want to measure voltage and current with Arduino (through a voltage divider, of course). I'm not sure, how to either detect nor measure ...
3
votes
2answers
87 views

Controlling voltage and current from chip?

I'm well aware that this question perfectly showcases my spectacular ignorance, but oh well. It's a simple enough question, so here we go. I have a 595 chip (SN74HC595) wired up to an Arduino, fed by ...
3
votes
1answer
71 views

Digital I/O threshold voltages for ATmega32u4

What are the voltages on a ATmega32u4 (eg Arduino Leonardo) such that a HIGH or LOW is read? I want to ensure that I'm reading the chip reference manual correctly, where Table 29-1 says: VIL: Input ...
3
votes
1answer
319 views

How to understand the “power economy” of a voltage up-converter (boost converter)?

My online video Arduino instructor makes use of various devices to amplify signals, currents, and voltages. This seems like magic to me. For instance, he has 4 AA batteries with 1.2V each. He says "...
3
votes
1answer
383 views

How to create a smooth change in voltage?

We are given two voltages A and B between 0 and 5V. So how do I generate a smooth/continuous analog change in voltage from A to B in a predefined time? The current with that varying voltage is 1 ma ...
2
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3answers
1k views

Convert from 3 V to 5 V

I'm new to Arduino, electronics, and this forum. I have made up a little project that connects an HC-SR04 ultrasonic range detector, and displays the distance on a 4 digit, 7 segment LED display. ...
2
votes
4answers
6k views

Reading pressure sensor using Arduino analog

I'm using a Arduino Uno to read pressure and I want to know if I have wired/coded the sensor correctly. I'm not sure I'm getting the correct readings (it could be the right readings - I just want to ...
2
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2answers
62 views

Arduino UNO socket

As I learnt so far is that Arduino UNO board has a socket for power input. The available power input range is between 7V - 20V, but the optimal usage range is 7V-12V. Here I am wondering: ---> if ...
1
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2answers
1k views

How does Arduino digital input pin measure its input voltage?

Just starting with my first Arduino project. In order to measure voltage in a circuit I connected my multimeter to two points in the circuit (for example before and after a resistor). I am interested ...
1
vote
3answers
1k views

PWM water pump flow control - in percent

I want to control flow level on 12V water pump with PWM pin, I'm using IRF520N MOSFET for that (and dedicated 12V power supply). I'm assuming, that setting PWM to full byte should give me about 100% ...
1
vote
1answer
27 views

How do I supply either (1) dual voltage or (2) negative voltage? [closed]

Sorry in advance if this question already exists--I tried to search but my keyword knowledge is shaky. I have created a Colpitts oscillator on breadboard using AA batteries as the power supplies. I ...
1
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2answers
67 views

How would I go about measuring an analog signal on my arduino mega that has both positive and negative voltages

I have a signal that fluctuates between -70mV and 50mV. How would I get the arduino to read this.. Ultimately I am trying to graph the data in real time so it looks like this. https://imgur.com/a/...
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1answer
115 views

How can I make an AC analog voltage with Arduino?

I am trying to create an AC voltage in Arduino. Until now I have only managed to get a square wave. How can this be achieved with Arduino? If I try: int up; int down; int out = 11; void setup() { ...
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2answers
117 views

Smart way to map digital pins to a for loop over analogue pins

First post here and I have very little Arduino/c programming knowledge so forgive me my ignorance. I am processing 18650 cells for a little powerwall project. I am using an Arduino pro mini ...
1
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2answers
606 views

Ams1117 worked fine on battery, up in smoke with 12v power supply [closed]

I have a circuit that worked fine on a a 12v lead acid battery for a day. Once connected to a 12v 3a power supply it didn't work properly and then the ams1117 5v burned up and so did a 3.3v one within ...
1
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1answer
36 views

Powering arduino and node mcu [closed]

I want to power up my Arduino and my Nodemcu via 12 V , 1 A power adapter (it's an AC to DC power Adapter). Recently I have two voltages regulators: a 5 V for nodemcu and 9 V for Arduino Uno. The ...
1
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2answers
64 views

How to produce multiple DC voltages for a single project

So the title pretty much says it all, but for an example, I have an arduino board, 5-12 V, an LED bank 18 V, and an ultrasonic mister 24 V. I know some brute force methods to power ...
1
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1answer
57 views

Why does reading an analog pin give a different results when interfacing with Processing?

I am interested in measuring the voltage over an analog pin (A6). When I use the Arduino IDE to print the results through the serial I get values around 300. Here's the code void setup(){ Serial....
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2answers
68 views

Need Input: Wait for voltage input to begin script & when voltage maintains 0V for X amount of time Reset and wait for Voltage Input

So I'm currently working on an automotive set up. I'm using a 555 timer to emulate a turn-signal alternating voltage pulse (12V to 0V and repeat) for debugging purposes which is output to turnPin/A1. ...
1
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1answer
157 views

NodeMCU ESP12 Voltage

I'd like to power an NodeMCU off of four 1.5v batteries. That's 6v. Depending on the source I've read that 5.1v will fry the board and, just a few clicks later, that the board will take up to a 20v ...
1
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2answers
186 views

I have cooked 3 regulators applying 12 V to RAW pin. Am I doing something wrong or did I get a bad batch?

I'm trying to make a simple keypad lock that has a 12 V magnetic lock. I supplied 12 V to the RAW pin on the Pro Mini with plans to actuate the relay with the 5 V from VCC pin. The lock was grounded ...
1
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1answer
404 views

Using voltage divider to read voltage from sensor

Good morning, I would like to use an Arduino Duemilanove to read the voltage signal generated from a current sensor (CSLA2CD). The datasheet for this sensor can be found here. The problem is that ...
1
vote
1answer
186 views

HC-06 RX pin usefulness

I have a HC-06 bluetooth module. The module has an RX and TX pin (the RX pin receives data and TX transmits data) which connect to the TX and RX pin of an Arduino respectively (in my case an Arduino ...
1
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0answers
28 views

Some noob questions regarding Arduino Nano based drones [closed]

Foreword: I am doing my Bachelors in Aerospace Engineering and part of the requirements to graduate (and get a good grade) is that I must complete 3 projects of my choice, and it must be unique. So in ...
1
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0answers
42 views

Measuring battery voltage [closed]

I am trying to use this way to measure my battery voltage at least approximately, but I am getting weird results. I am running breadboard atmega328p with internal 8 MHz and powering it from a LiPo ...
1
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0answers
53 views

Transistors to use for eight voltage sweeps from two PWM Arduino pins

On my Arduino Mega, there are two PWM pins open. There are eight analog voltage inputs to a datalogger. They are connected through a PCB, and I need test them with a DC voltage sweep. (There are many ...
1
vote
0answers
68 views

ADC pin shutting off on its own under certain condition

A0 pin not working when full PV system in use I am using the DFRobot Leonardo with Xbee R3. I am using the A0 pin to read a 0-5V voltage from my voltage sensor, which samples and steps down 130VDC ...
1
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2answers
1k views

Power Arduino with 12V while using Serial Communication over USB

I'm going to build a 8x8x8 Led RGB Cube, therefore I will need a lot of Power which the arduino can't handle, so I'm using a 12V 20A (I know 20A isn't necessary but I had one laying around). So the ...
1
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4answers
108 views

Automotive Lighting Control Module

I am looking for an Arduino-based solution for an automotive lighting application. System Requirements: Able to Operate in Automotive (Interior) Environment (12 +/- 2V DC Voltage) Minimum 3 12 V ...
0
votes
1answer
759 views

Logic level converter not working?

I'm trying to connect a 3.3v depth sensor to an Arduino uno. The logic level converter does not seem to send any current over (the sensor does not work and the voltmeter reads nothing). I tested the ...
0
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2answers
105 views

Can the Arduino be hurt by connecting too many LEDs in serial?

Today I learned about Vf for leds, after founding out that 3 leds in series driven by 5 V did not make them light up while 2 did. However, I also read that it is quite bad for a power source to use ...
0
votes
1answer
25 views

How to build an µC controlled power regulator?

The idea: Use an Arduino-like µC to control a set of CPU fans by control the voltage the CPU fans receive. My question: How can I do this in an easy way? Yes, I know, there is PWM but this is not ...
0
votes
1answer
29 views

Different voltage sources across Vin and DC jack

So I understand that the USB VBUS circuitry turns off provided there is a high enough vin voltage using the PFET and comparator. I can see that the DC jack is connected to the Vin pin via a diode. ...
0
votes
3answers
2k views

Combining code for multiple sensors (Current and Voltage Sensors) in one program

I need to operate 2 different sensors (Current and Voltage) simultaneously. I have managed to run each one of them separately and I don't know how to manipulate the code so they could work together. ...
0
votes
1answer
223 views

Arduino controlled light dimmer software

I found this software: /* AC Voltage dimmer with Zero cross detection Author: Charith Fernanado <a href="http://www.inmojo.com"> http://www.inmojo.com </a> Adapted by DIY_bloke License:...
0
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2answers
91 views

Generate a ramp input with an Arduino Uno

Is there anyway to generate a ramp input from an Arduino Uno? A visual depiction of the pulse I am looking for is as follows: With other microcontrollers, I was able to use their in-built DACs, ...
0
votes
1answer
601 views

Read frequency of input in digital pins

This is a somewhat theoretical question: Let's say I have some sensor that sends digital signals to one of Arduino's digital ports. Now, I don't know the frequency it sends those signals in. For ...
0
votes
1answer
262 views

Arduino Nano off 9V : is there any change to output?

I'm building a test circuit on an Arduino Nano that consists of a simple 220 Ohm resistor and an LED on pin D2 which is routed back to GND (ground). It's as simple as this: It's running a very ...
0
votes
1answer
451 views

Will Nodemcu support 4AAA

Will Nodemcu support 4AAA batteries which is 6v approx, or should i go with 3AAA batteries which is 4.5V approx. And one more question , is it ok to use AA instead of AAA ?
0
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2answers
84 views

3.3V from 5.0v outlet

I am working with an Adafruit Feather 32u4 FONA board. I want to connect a GPS module I have worked with before (3.3V required) but am not having much luck. I have studied the pinout of the board and ...
0
votes
1answer
38 views

Using a DFRobot Voltage Divider

I'm reading on the DFRobot website to implement this Voltage divider: Analog Voltage Divider SKU: DFR0051 void setup() { Serial.begin(9600); } void loop() { float val; float temp; ...
0
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1answer
345 views

PC Fan Speed Control [closed]

I am working on a project to blow air gently through a number of pipes and variable speed. I would like to use a standard PC case fan and have control of whether the fans are on/off and also what ...
0
votes
1answer
899 views

CH340 3.3v stability

I want to use the 3.3v on a cheap Arduino Nano clone as my ADC analog reference voltage. The 3.3v comes from a regulator inside the CH340 USB serial chip. I've measured the voltages (My DMM is NOT ...
0
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2answers
1k views

Powering a DC motor with an external battery

I'm working on a project where i need to control a 6 volt motor with an Arduino. The motor that I'm using requires 6 volts so I'm using a 9 volt with a voltage divider to get those 6 volts. My problem ...
0
votes
1answer
464 views

Connecting ACS 712 30A to my Solar Panel with Arduino

I am trying to connect my Solar Panel (array of 2 x 265Wp 24v panels connected in series) to my Arduino UNO R3/Nano so that I can make a current/voltage measurement system that can be connected to the ...
0
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0answers
30 views

How to measure multiple voltages (Thermocoupes)

How would one measure many (20-100) small voltages in the 0-80mV range with an Arduino? I will need to amplify them and put them into the ADC. But i also need to switch between them. I want to ...
0
votes
0answers
22 views

Making a voltmeter for PV system over 60 VDC

I'm trying to make a voltmeter for my PV system that can range from 24 VC to 120 VDC. I'm aware of the fact that we have Arduino modules available that can work for 25 VDC system. However in my case ...