Questions tagged [voltage]

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36 views

AC Current sensing giving low readings (SCT013)

So now that I feel comfortable with using ADCs, I am attempting to measure the AC current with the SCT013 clamp with AC current sensor. Setup: I clamp the SCT013 around the HOT wire of a table lamp ...
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2answers
54 views

Slight dip on the GPIO 5v line when LEDs are on

I have my raspberry pi set up to do two main things: control 16 LEDs via 16 transistors each connected to an out pin. The LEDs are collectively fed the 5V from the GPIO. power a chip also on the 5V ...
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26 views

Clamp on DC Ammeter with Raspberry Pi to Monitor 12v Batteries

We are looking to use raspberry pis to monitor banks of 12v batteries in a real world environment. We currently are able to use a USB voltmeter from : http://www.digital-measure.com/html/...
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2answers
56 views

Voltage drop when RaspberryPi boots

Im trying to learn robotics with raspberrypi but im having a problem. I have 6 AA batteries in a batteryholder that are connected to a breadboard and with M-M jumping wires its connected to a LM2596S ...
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45 views

RaspberryPi is not provided with enough power

Im trying to learn robotics with raspberrypi but im having a problem. I have 6 AA batteries that are connected to a LM2596S adjustable voltage regulator module, Which then is connected to the ...
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2answers
32 views

do RPi3 3.3/5V pins output constant voltage even if the RPi power supply is changing voltage?

I want to power my RPi with a lithium ion battery. The RPi will be powering some devices which require constant voltage to power them. If I use a battery as supply for the RPi (which changes as it ...
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2answers
73 views

Convert 12V to 5V to power RaspberryPi

I have an Eleksmaker laser cutter which has a board with a 12V output (see top of image). I would like to power my RaspberryPi using this 12V output. What is the advantage of powering the ...
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2answers
133 views

What happens to the GPIO voltage after shutdown?

I don't have a Raspberry Pi laying around at the moment and I would like to detect if my Raspberry Pi is shuted down. My Idea is that maybe after the Pi shutted down the Voltage at the 3V3 pin will ...
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2answers
46 views

Measure Volt, Amps, Watt and Kwh of an external 12V system

I saw online some cheap hardware ~10$ that can measure Volt, Amps, Watt and Kwh and display the results on an LCD screen. I could buy and plug these on my 12V solar panel system to monitor it. (5 of ...
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1answer
56 views

Is there a piece of hardware which enables hotplugging sensors to the breadboard?

The idea is the following: I have a Raspberry PI connected to a breadboard. To this breadboard, I would like to connect (digital and analog) sensors and actuators while the PI is running. Or remove ...
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3answers
56 views

Voltage dropped significantly on GPIO 4 with a relay coil

I have a Raspberry PI 3 B+, and when I activate the GPIO 4 as output and checking agains a multimeter I get its 3.3V as expected. If I connect the GPIO4 to one end of a coil (http://www....
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0answers
27 views

LCD Installation freeze because of low voltage?

i try to install my LCD 3.5 waveshare, but when extracting the folder and use sudo ./LCD35-show it starts shortly and then freeze. I Got the thunder icon and the freezed screen. Might this be the ...
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3answers
67 views

GPIO to detect if external 5v source is turned on or off?

I'm using a Pi Zero W and I'd like to connect a 5v source to a GPIO pin to detect if the 5v is on or off. I know the GPIO is only digital I/O and 3.3v max, so is a simple voltage divider enough or do ...
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2answers
62 views

Is 5V out on the Pi Zero W unregulated?

I want to power a 5V relay breakout board from a Pi Zero W. I believe the 5V pads are "raw" and a "pass through" voltage? Is this correct?
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3answers
120 views

MCP3008 minimum current(resistors value)

I want to measure some battery voltage in a range 0V-4.2V with MCP3008(VDD=VREF=3.3V). I used a voltage divider with R1=2.7MOhm and R2=8.2MOhm, but it didn't return correct value, I used resistors ...
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1answer
352 views

Seeed ADC (ADS1115) with Raspberry Pi 3 B+to read voltage values using python3

I'm using a Seeed 4-Channel 16-Bit ADC (ADS1115) for Raspberry Pi with a Stretch installed Raspberry Pi 3 B+ and successfully configured following below guidelines & GitHub. http://wiki....
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2answers
354 views

Water Level Detection Sensor 3.3 Volt vs. 5 Volt

I'm using a classic Water Level Detection Sensor or sometimes called Rain Water Level Sensor together with a RPI 3+ to detect water in a Pot (Link). So I don't need any analog reading but only the ...
4
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2answers
372 views

Reading Voltage Input on ADC

I'm thinking of using the Waveshare ADC board with a RaspPi 3 to monitor the current driving a DC brushless motor. I've run through the waveshare examples, and I can handle reading inputs ...
0
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1answer
128 views

is undervoltage on a pi3b+ a problem of the board?

Like many others I got the undervoltage warning on a pi3b+. I see most answers blame a poor power supply. I plugged mine to a bench power supply to test this, I set it to 4 amp and kept getting ...
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0answers
105 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 ...
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0answers
56 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 ...
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2answers
193 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
69 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 ...
1
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1answer
38 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
44 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 ...
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1answer
53 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
31 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
842 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
4k 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 ...
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1answer
293 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
192 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
32 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 ...
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1answer
468 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
865 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
67 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
107 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
1k 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....
1
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1answer
735 views

GPIO Voltage tolerance for input

I have not been able 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 ? Does somebody have a ...
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3answers
611 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
118 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)?
0
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1answer
72 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
1k 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
474 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
377 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 ...
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1answer
100 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....
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1answer
426 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 ...
1
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1answer
133 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 ...
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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 ...
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1answer
64 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 ...
0
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1answer
111 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, ...