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Questions tagged [voltage]

The tag has no usage guidance.

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23 views

Control 12V motor from 3.3V GPIO with external 12V Power Supply

I have a 12V motor, which I need to control from my Raspberry Pi (through the RaspiRobot Board). However, the RaspiRobot Board gives me only 3.3V for the motor. At the same time, I have a 12V adapter ...
0
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0answers
18 views

Checking Voltage Level at GPIO Pin Program

I’m trying to write a program that will loop through 3 GPIO pins connected to an external charging pad and see if a device has been placed on the pad (high voltage). If high signal is detected the ...
0
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1answer
113 views

Turn a Raspberry Pi into a voltage tester

I would like to create a voltage tester like the one described in this video, using 555 ic, and then connect it to Raspberry Pi, in order to log the frequency a 220V waterpump is switched on. My ...
1
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1answer
44 views

Wiring that won't damage my pi [closed]

A while ago, I decided to wire up a Raspberry Pi (Zero W) to a few peripherals, but it stopped working shortly afterward (not entirely, but I think it was undervolting the power rails). I had ...
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1answer
22 views

Lipo Battery Voltage Drop When Pi 3B and LCD Screen Are Both Connected to Powerboost 1000

I have a Raspberry Pi 3B and LCD Controller Board connected to a Powerboost 1000 Basic. A Lipo Battery Charger is connected to the Powerboost as well. I noticed if I remove the LCD Controller board ...
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0answers
35 views

Is it possible to plug in and out sensors, LED-s etc. on the breadboard while the Raspberry is running?

What I would like to do, is to let the Raspberry Pi run and while it is running, connect and disconnect eg. sensors whenever I please to/from the breadboard WITHOUT turning off/disconnecting the Pi ...
-1
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1answer
35 views

Raspberry PI Portable USB Charger [duplicate]

I bought a $5 usb charger that I am using to power my Raspberry Pi. The charger works decently but I am noticing that every once in while the raspberry pi will reboot. I have read that some chargers ...
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0answers
25 views

5v pin usage for 433mz transmitter receiver

I've bought a 433mhz transmitter receiver and I made a check on model SODIAL(R) 015274A2 the strange is in two links we have 2 differente specs, one says: https://www.amazon.com/SODIAL-433Mhz-...
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2answers
246 views

FM transmitter antenna length

I'm a new raspi user, and I'm starting to build some projects with hardware. I would like to try this FM radio station for example, but I have a doubt about the antenna's length. This is important ...
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2answers
564 views

Get reading of RPI supply voltage

On the most recent pi I've been playing with I've noticed the under-voltage lightning bolt warning, discussed on this question. My question is whether there's a way I can access the voltage reading ...
0
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1answer
75 views

PWM and Output Voltages at High[er] Frequencies

I am attempting to set an analog voltage control signal with a Rasberry Pi 3 B+. My Python 3 script uses RPi.GPIO to output PWM across a range of duty cycles to simulate analog output---without the ...
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2answers
93 views

How to increase voltage of USB ports on the Raspberry Pi 3 Model B?

I have been trying to build a Raspberry Pi laptop, and I found an issue where my screen required power at all times to run , so I decided to plug the screen in to the USB port in the Raspberry Pi. ...
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2answers
26 views

Ground running back through logic shifter?

Sorry if this is a silly 'beginner' question, but I'm still only just getting into working with the Pi. I have a Pi Zero that I want to use to drive a module of a few WS2812 LEDs. Because the GPIO ...
0
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1answer
237 views

Pi 2B, Under-voltage detected!, no lightening bolt, +5 is rock solid at 5.01VDC

This is a weird one - have had 2B in service for three years, but it crashed last week. Rebuilt with a new Pi 2B+, but saw undervolt errors on the rebuilt system that would have gone unnoticed, so ...
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2answers
484 views

Powering a sensor using an external power supply board

In my Raspberry Pi project, I need to measure a distance. To do that, I have an ultrasound sensor called "AJ-SR04M" (it is basically a waterproof HC-SR04 I believe). Characteristics of the AJ-SR04M: ...
0
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1answer
54 views

Why my gpio input changes the internal resistance when running the python code? [closed]

I have a raspberry pi receiving inputs with a 300k resistance connected between the voltage input (12V) and the gpio. When my python code is not running the voltage at the gpio is 1.7v, but when I ...
1
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1answer
80 views

Supply voltage 5V issue from Raspberry Pi 3

I have a sensor connected to a Raspberry Pi 3 and I see some variations of the signals which is not expected. These variations seems to be due to the supply voltage 5 V from the Raspberry Pi. ...
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3answers
987 views

Powering RPI 3 and using relay from same source

I want to build something of a smart home device such as a smart switch /outlet for example that controls something like a light. However, I don't know what the wiring should be Like, if it's possible....
0
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1answer
295 views

GPIO Voltage tolerance for input

I don't managed to find the input tolerance on I/O pins, especially on the Input pins. If I apply a voltage 3,6v (3.3v +0.3) on an input will it be dangerous or is it ok ? If somebody have a technical ...
0
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3answers
341 views

Turn on and off 5V to 12V Relay

I want to use my Raspberry Pi to turn on and off a 12V current for a certain amount of time. I've read a lot on this forum and I've understood that the 5V GPIO Pin is... Not GPIO, meaning that I ...
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0answers
68 views

Pin on off engine javascript nodejs

I have a little engine linked at pin 1 and 3. How can I turn it on and off throught nodejs? Is there also a way to control how many volts are sent (to make the engine faster or slower)?
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1answer
52 views

Raspberry Pi3 using different ground pins for multi ldr toy car

I am working on a toy car which is following the "light" and I am totally new at raspberry pi and circuits. In this video, he is using 1 ldr. I need 3-4 ldr to turn the car to left or right. (I am ...
4
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1answer
829 views

Undervoltage symbol

So I have this undervoltage symbol on my raspberry 3+, and it's annoying. Now I have a powerbank with 5V and 2.1A(fast charger) and the symbol is there as well as on the old pi-2b+ AC adapter. So ...
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2answers
326 views

DAC MCP4725 not working with raspberry

I am using raspberry pi 3. I am trying to run the AC induction motor for that I want an analog pin. In raspberry pi model doesn't have an analog pin. All pins are digital IO pins. So I have tried MCP ...
1
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1answer
213 views

Will accidentally powering a pi with more than 5V break it?

I have a variable power source(5V, 6V, 9V, 12V, etc...) with a usb plug which I had powering my pi 3B a few months ago, but one day (a few months ago) I accidently had the power source set on 6V(it ...
4
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1answer
96 views

Raspberry Pi's reaction to 7.2 Volts applied to a GPIO pin?

I was using a Raspberry Pi 3 model B in a project. The Pi was connecting to a web socket and receiving data from the user on a PC or whatever device connected to the same socket. It was fine at first....
2
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1answer
294 views

GPIO pins are always low

I'm using a Raspberry Pi 3 Model B running Raspbian Stretch Using it somewhat like an RC car with an L298N H-bridge motor driver to control two DC motors. It was working fine until a few days ago ...
0
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1answer
107 views

Where to connect PWR_LOW_N?

We're developing a compute module board, and added the undervoltage circuit. Unfortunately, I cannot find where to PWR_LOW_N is actually connected. I have found some saying it's connected to GPIO 35 ...
4
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2answers
3k views

Pi 3 Model B+ doesn't boot - Power Supply or broken?

I just bought a Raspberry Pi 3 Model B+. I also bought a power supply that the reseller sold specifically for the Pi - it delivers up to 3A. However, the Pi doesn't boot. I gives me the rainbow screen ...
0
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1answer
60 views

GPIO is not giving maximum 3v3 output

I have a raspberry pi model B, NO B+ OR 2B, jus the model B. I am using it as a brain for a robot but I’m having a little trouble with the motors. I am using the GPIO pins to power it but when I set ...
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0answers
89 views

Raspberry Pi 3 not booting - no LED's, hot CPU

Hey everyone :) I've just encountered a strange problem. My Raspberry Pi 3 V1.2 is not booting anymore. The LED's don't flash at all, the CPU becomes hot and the voltages are kind of wrong. On the 5V ...
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1answer
90 views

Noob Looking to detect LED voltage 0v LOW, 1.8v HIGH on another device

Trying to learn about the PI and I have acquired a pi Zero W with the GPIO header. I have an external device that signals activity via an LED, which blinks @ 1.8v 2X and then remains on until reset, ...
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1answer
263 views

Precision of Raspberry Pi GPIO outputs voltages [closed]

Raspberry Pi has several output voltages, GPIO outputs theoretically giving exactly 0V for False and exactly 3.3V for True, 3.3V line and 5V line. However, how precise are these outputs? Can the ...
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2answers
3k views

TP1/TP2 equivalent for Raspberry Pi 3 B

Is there "old" TP1/TP2 equivalent for Raspberry 3 Model B to measure voltage?
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4answers
1k views

Raspberry Pi GPIO input voltage Limit

I am doing a project in which I have a component that outputs a 5 Volt signal. Since the Pi is only able to handle 3.3 V I connected the signal to a voltage divider. I used a 4.7 kiloOhm and a 2.2 ...
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1answer
301 views

Inconsistent i2c bus address listings causing sensor reading issues

I am using a raspberry pi 3 with an Atlas Scientific DO sensor to try and create a wireless sensor network for an aquaponics system. Everything works fine when I am running the system in my home in a ...
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0answers
339 views

Issues using SPI pins on Raspberry Pi 3 with MCP3008 ADC for Voltage Sensor [closed]

I am trying to create a voltage sensor using a Raspberry Pi 3 with Raspbian (February 2017 release because that is the one I need for the rest of my project) by connecting the SPI pins to an MCP3008 ...
0
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1answer
746 views

3.3v to GPIO input using relay

I'm exploring various ways to detect higher voltage using the Pi and have come up with a circuit where the 5v would energize the coil of a relay which would switch 3.3v from the Pi's internal 3.3v ...
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3answers
455 views

Detecting 5v from external source using voltage divider

I'm working on detecting whether or not an external 5v supply is on or off and found a few helpful related questions, specifically this one: Detecting 5V output from USB charger via Raspberry Pi From ...
5
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3answers
3k views

Calculating resistor value for transistor

I'm creating a circuit with an infrared led and a transistor connected to a gpio pin. I'm currently using 5v with a 40 ohm resistor (four 10 ohm resistors chained) but I'm not sure what resistor to ...
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2answers
272 views

Connection of 220V Doorbell to Raspberry Pi GPIO

I have a power connection going from a button outside of my house to the doorbell box. I want to take a branch of this wire, and connect it to a raspberry pi to detect the button being clicked. The ...
3
votes
2answers
376 views

Voltage on undefined GPIO pin

If I do not specify the output of GPIO pin (like GPIO.output(4, False)), I always have a voltage of 1.3V on this pin How can I set all pins to 0v? and why are undefined pins have this voltage of 1....
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1answer
43 views

LEDs won't follow pattern (voltage issue?) with Pi 3

First and foremost, let me say that I'm new to electronics and the Raspberry Pi. I'm a programmer. I have never done this type of project before. Now, I have a Raspberry Pi 3 model B that controls my ...
0
votes
1answer
542 views

Measuring 0-5 V DC with a good accuracy (~10 mV) using a Raspberry Pi

I'm totally new to Raspberry Pi and I want to use it for an important school project. My aim is to build a laser-seismograph using a laser pointer and 4 photodiodes which basically measure the laser'...
0
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0answers
192 views

How to determine if a USB power supply is safe to use with a Raspberry Pi?

I have a Raspberry Pi 3 that appears to have been destroyed this morning. I purchased a no-brand USB mains charger suitable for UK use (and CE certified) from eBay, and I am almost certain that was ...
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1answer
222 views

What Circuit Should I Use to Hardwire Raspberry Pi to Doorbell?

I am trying to connect my raspberry pi to my hardwired doorbell in order to send a text message when the doorbell button is pushed. I have successfully sent the text message using a button connected ...
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1answer
714 views

How to check if 16x2 LCD is 5 volts or 3.3 volts?

I got a 16x2 LCD display but I have no clue if it's 5 volt or 3.3 volt logic. I'd like to use it on a Raspberry Pi but I'm afraid to just plug it into the 3.3 volts if the display is 5 volt. The ...