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Questions tagged [voltage]

The tag has no usage guidance.

0
votes
1answer
37 views

Voltage sensor Calibration

We had used a voltage sensor unit to measure the voltage of the odroid board using an Arduino Uno. wWhen I uploaded the sketch and got the output, the value which was being displayed was around 4.7 to ...
0
votes
1answer
44 views

Detect power interruption on NodeMCU

Im using a 5v 1A power supply and connected to VIN pin on the NodeMCU. I also use 18650 battery to keep NodeMCU running in case the power supply shuts off due to power interruption. I'm planning to ...
1
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0answers
47 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 ...
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 ...
2
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2answers
58 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 ...
0
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2answers
114 views

Difference between 3.3v & 5v

Im quite new to arduino in general and i'm sorry for the beginner question. could someone explain what the 3.3v and 5v on boards do? I know their voltages. but can you run one on the other? whenever ...
1
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2answers
49 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/...
1
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1answer
28 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 ...
0
votes
1answer
116 views

Connecting 5V arduino logic with 12V car logic

I need to connect arduino to K-Line in my car's OBDII port. I used an L7805 to power the atmega but how can I interface 12V car logic with 5V arduino logic? The problem is, the connection has to be ...
0
votes
1answer
179 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 ...
1
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2answers
53 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 ...
0
votes
1answer
28 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
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2answers
68 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 ...
1
vote
1answer
45 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....
0
votes
1answer
37 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
votes
1answer
170 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
0answers
83 views

HC-05 3.3 voltage regulation

HC-05 Bluetooth RX requires 3.3 v (TX has a regulator built in) I understand my uno and nano are 5v Ive connected a 3.3v Zennor in series with a led and resistor and with multimeter established the ...
1
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2answers
62 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. ...
0
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0answers
720 views

Controlling motor direction with ESP8266 and Motor Shield

I recently acquired a NodeMCU ESP8266 Board and a NodeMCU Motor Shield, which I have connected very simply to two motors on an RC car. The idea mostly came from this tutorial. From what I understand ...
0
votes
1answer
221 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 ...
-1
votes
2answers
29 views

Batteries and amps in parralel [closed]

So, i am about to buy a brushless motor a ESC and a 18650 batteries for my arduino. The batteries "specs" is 3.7v and 20a, if i would to put 2 and more in parallel would i get 7.4v 20a or 7.4v 40a? ...
0
votes
1answer
279 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 ?
1
vote
1answer
103 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 ...
3
votes
2answers
76 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 ...
6
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3answers
16k 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 ...
-1
votes
2answers
57 views

Max current per pin is 40 mA. But it is always 40 mA?

I need to calculate resistor for a PNP transistor. To do this I need to know the voltage and current. I know voltage is 5 volts as it is easy to find in the internet, but how about current? I mean ...
0
votes
1answer
83 views

Have I fried the voltage input on my Arduino Nano?

I tried using my Arduino Nano in a circuit, switched on power to the circuit and heard a crack and smelt a bit of burning - something shorted. I have plugged my Arduino into my PC with a USB, the ...
0
votes
1answer
48 views

Designing around Output pin limitations

I'm new to Arduino and am working on a project with my son. We are using the LillyPad USB board (schematic) to drive a bunch of LEDs (LED Datasheet). Our project is based loosely off of the 'Turn ...
0
votes
3answers
1k 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. ...
1
vote
1answer
92 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() { ...
0
votes
1answer
715 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 ...
1
vote
2answers
106 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
877 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
0answers
65 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 ...
0
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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 ...
2
votes
4answers
4k 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 ...
3
votes
1answer
199 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 "...
0
votes
1answer
95 views

Arduino Micro not providing regulated power

I have an arduino micro that works fine off USB. I need to power it from an external 12V power supply. When I connect the 12V supply to the adjacent VIN and GND pins, the arduino will not power up. ...
1
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4answers
105 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 ...
2
votes
3answers
745 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. ...
1
vote
2answers
494 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 ...
0
votes
2answers
987 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 ...
1
vote
2answers
137 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
vote
3answers
875 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% ...
0
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0answers
15 views

Attempted to disable autoreset - now the voltage regulator only outputs 4.0v

I followed the guide from the Arduino website, by placing a 10uF capacitor between GND and Reset. However, now the voltage regulator only provides 4v (Vin=13V). It correctly has 5V when being powered ...
5
votes
1answer
134 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 ...
-1
votes
1answer
598 views

Understanding schematics: resistors attached to Attiny85 pins V-USB

I'm currently trying to create my own Attiny85 usb thumb(to mimic an joystick). I understand that I have to limit the voltage on the attiny's pins that are connected to the D+/- pins from the usb. In ...
4
votes
3answers
2k 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 ...
1
vote
1answer
331 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 ...
4
votes
1answer
325 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 ...