Questions tagged [voltage]

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40 views

Raspberry PI GPIO protection

I'm designing a PCB to mount and interact with a raspberry pi4. One of the things I need it to do is drive a 24V relay. This circuit has worked great with some controllers I've used where the outputs ...
1
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1answer
58 views

raspberry pi prevent overload current from turning on a high current motor

I am trying to use only 1 power supply instead of 2 to power Raspberry Pi and motor, but when I turn on the high current (>10A) motor, it will lead to the Raspberry Pi restarting. I guess it is ...
0
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1answer
93 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 ...
2
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1answer
485 views

How can Rpi I2C read a Coulomb Counter, up to 18V, 10A?

I"m building an autonomous boat with a solar panel. The heart of the boat is a Raspi zero which contains a small program doing the navigation. I've got a 3S li-ion battery of which I'm already ...
0
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1answer
50 views

12V Switch advice

I’m new to RPI and have a project. Please take a look at the fire switch on the diagram. I would like to add a RPI on that loop and see when the fire button is depressed. This is a 12V system so any ...
0
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1answer
33 views

When To Use a Level Shifter (Arduino Uno + Pi SPI)

I was following this guide from Adafruit to flash an Arduino with a Pi using AVR-Dude over SPI: https://learn.adafruit.com/program-an-avr-or-arduino-using-raspberry-pi-gpio-pins?view=all I noticed ...
1
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1answer
459 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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0answers
24 views

Change DVFS scale on raspberry pi in real time from the CLI?

I am creating an app that will showcase the power efficiency of the raspberry pi with different DVFS scaling. I am wondering whether there is an option to change the settings from the CLI, since that ...
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0answers
43 views

Retropie Battery Powered Handheld

I am planning to build a Retropie Handheld and want to use: 2 of these in series: https://www.jaycar.com.au/14500-rechargeable-li-ion-battery-800mah-3-7v-nipple/p/SB2300 paired with one of these: ...
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0answers
135 views

RPi4 won't power on from 5V if any load is present on 3V3

The short version: Raspberry Pi 4B, rev 1.1, doesn't turn on when provided with 5V on the pins 2&4 if any load is present on the 3V3 (pins 1&17). However, powering the Pi from a USB-C source (...
0
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2answers
292 views

How dangerous is to input 4.1V to the GPIO?

I'd like to power a few sensors I'm adding to my RPi (Zero W) using a battery with maximal voltage 4.1V (coincidentally, the same battery used to power the RPi, except that there's a voltage amplifier ...
1
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2answers
891 views

Rpi interfacing MCP4725 12-bit DAC pproblem

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 ...
0
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2answers
104 views

16 Channel Sainsmart relay board connected to raspberry pi zero w, hydrosys4 app not stopping relay / turning off relay

Within the Hydrosys4 app Settings page in the actuators test section I can set the app to pulse the GPIO and I get the LED indicator on the relay board and the relay engagement but the relay does not ...
0
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2answers
191 views

Is there a workaround to make the Raspberry Pi 4 output 1.8 V?

I have a Raspberry Pi 4 Model B and I want to use it to flash a Coreboot BIOS image to a SPI EEPROM chip (using either flashrom or a program called "spi flash programmer" that is originally ...
0
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1answer
58 views

Raspberry pi voltage between PP3 - PP27 is 0.01V is this normal?

I measured voltage using a multimeter between PP3-PP27 and it was fluctuating between 0.01V to 0.06V is this normal? The entire problem can be found here: USB ports recieving power but not working on ...
0
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1answer
50 views

Can i power my Raspberry pi 3 b+ with a micro-USB to USB thats connected to a USB charger?

I read in the manual, that u should charge it with 5V and 2.5 amp, but im not sure. I already read, that a undervoltage can damage the pi and that USB 3.x would be enough, but I still dont know how ...
2
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2answers
158 views

raspberry pi fan don't start to spin without hand help!

Raspberry Pi has recently added fan control feature in its raspi-config tool. This made me curious to add a fan to my RPI 4. I did it recently with a 680-ohm resistor, 2N2222 transistor, 1N4007 diode, ...
3
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4answers
503 views

Low voltage warning despite using official power supply tested at 5.2V

I bought the Official power supply but when I use it in my Pi 3 model B I get a warning saying: "low voltage, please check power supply". I have checked the voltage on the Pi using a ...
1
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3answers
31 views

Avoiding voltage drops when simultaneously using multiple DRV8833 motor drivers

I am using three DRV8833 motor drivers. The power supply is currently a usb cable with the ground and power connected to a breadboard with the three motor drivers attached to them. When powering all ...
0
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0answers
14 views

Driving 6 electric channels on/off and voltage (48A / 30-41V) from pi

I would like from a pi, to drive a current of 48A and regulate voltage between 30-41V (1440-1968W !). Furthermore, this current will be split into 6 input, and I would like to be able to switch on/off ...
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2answers
110 views

GPIO 3.3 V signal still readable after inputting high resistance values

I recently obtained a raspberry pi 4 (8GB) and I am trying to understand the GPIO behavior and ran into an event that I don't understand. I have set-up a simple script that allows pin 36 (GPIO 16) to ...
0
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0answers
53 views

Raspberry Pi 4 Undervoltage warning even with official AC adapter

My Pi 4 is relatively new and I previously used a 5V 3A tablet charger from an old Huawei device to power it without issue. Recently, a lightning bolt started appearing at the top right of the screen,...
0
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0answers
23 views

Calculating a time-varying voltage output that simulates a modulated carrier wave

So I have this measurement instrument and I want to transmit its data (database files from MySQL) at low frequencies (80-100kHz) through a limestone cave ceiling to the surface. Disregarding the ...
0
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1answer
59 views

Connecting Differential pressure sensor MPXV7002DP to Raspberry Pi 4

MPXV7002DP is analog sensor which measures differential pressure and requires 5V supply voltage and gives an output voltage of 4.5V. However, I want to get the digital output so I will connect the ...
1
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1answer
512 views

Raspberry Pi 4 - Booting with 3 USB attached Harddrives causes Crashing

I use my Raspberry mainly as a fileserver. I've attached 3 harddrives, 1 of them being an SDD and 2 Mechanical 3.5 Drives. When powered on, everything seems to work. However, when booting, the initial ...
-1
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1answer
41 views

Dim when not configuring any GPIO pins; why?

I am an absolute beginner with the Raspberry pi and also know only basic electronics, so please excuse me if this is a very basic question. I wired my Raspberry pi 4 like this to control an RGB LED. ...
1
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2answers
3k 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 ...
1
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0answers
93 views

Change the CPU Core Voltage from terminal

I was wondering if anyone is aware of how I can change the CPU Core Voltage of a Raspberry pi using system calls from the terminal. I know that we can do this by setting the over_voltage parameter in /...
0
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3answers
936 views

Low voltage on raspberry pi?

I have an old charger from my RP3 using in RP4 with micro-usb -> usb-C cap on it. I have a feeling that my Pi has not enough power- When I start Pi with fan connected to pins, it makes sounds like ...
0
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1answer
268 views

Monitor the power consumption in real-time (in Ampere or Watt)

I'd like to monitor in real-time the power consumption of a RPi. (0.5A, 1A, 2A, etc.) I know this can be done with a multimeter in ammeter mode in series, but I thought maybe there is an easier method,...
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2answers
59 views

How can detect a very low voltage (0.2 V) with the Raspberry Pi? [closed]

I'm a beginner in electronic and I want to use a GPIO input to detect 200 mV. Is that possible ? I think that we can increase the voltage, decreasing the amperage. But I don't found a way to do it. ...
1
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1answer
36 views

Programatically Establishing When RPi Supply Voltage is Too Low

Responses to this post: How does RPi "know" when it hasn't got enough power indicate that there is a digital input somewhere on the RPi which indicates what the supply voltage has ...
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0answers
47 views

Is the low voltage danger only during boot or during operation too?

I went to an authorized reseller, but they gave me this charger for my Raspberry Pi 3B. I used Etcher to write the August 2020 version of RPi OS to the SD card and it boots fine. However, during boot ...
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0answers
28 views

Smartmirror: i2cdetect and voltage

I build my first smartmirror and I have two issues. First of all this is my setup: RASPBERRY PI 3 Model B LG-Philips LP173WF1 (TL)(B2) 17,3" LED Display Screen (non-glossy) Full HD Hdmi ...
1
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2answers
129 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 ...
1
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3answers
120 views

Best voltage for a Raspberry Pi 3B

I have 5.0V 3A and 5.2V 3A regulated supplies that I can repurpose for my Raspberry Pi 3B project. Am thinking of using the USB power jack. Which should I go with? 5.2V would seem to be within the ...
4
votes
4answers
1k views

Voltage monitoring of battery pack (i.e. before voltage regulation)

I am looking to use four 18650 batteries and a step-down DC-DC converter to power my Raspberry Pi 4. The negative terminal of the DC-DC converter is common for the input and the output. I would like a ...
1
vote
1answer
109 views

Can Rpi GPIO pins be used to drive a DC motor? [closed]

I tried to GPIO pin to high and I cannot see output voltage. I try every solution but no one works for me. import RPi.GPIO as g g.setmode(g.BOARD) g.setup(16, g.OUT) g.output(16, g.HIGH) I look GPIO ...
1
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2answers
417 views

can undervoltage damage Pi 3?

I was running a Pi 3b model from an "insecure" power source, aka unknown car radio USB, no idea how many amps it gives. but the lightning symbol appeared on the HDMI screen, then the screen flicked a ...
1
vote
1answer
274 views

Issue with a 12v switch via GPIO output

I am a beginner when it comes to electronics so I would appreciate your help with a simple project I am working on and have been struggling with for several days. The idea is that I have a PIR Sensor ...
6
votes
3answers
24k 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
votes
1answer
381 views

GPIO Output Pin Reverse Current/Higher Voltage

I have a device with a built in voltage divider and opto-isolator. I need to send a pulse to from the RPi GPIO output to the input pin in the circuit. The output from the optic-isolator goes to an ...
0
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2answers
1k views

How to add Capacitors to Raspberry Pi

My goal is to add capacitors to the Raspberry Pi power-supply. Currently I have my raspberry Pi plugged straight into a portable 5v battery, this works fine. However, I want to be able to swap from ...
3
votes
2answers
4k 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 ...
2
votes
1answer
65 views

Cannot detect interrupt properly on a pulled up line

This is my simple setup simulate this circuit – Schematic created using CircuitLab This is my test program, using nodejs and rpi-gpio. var gpio = require('rpi-gpio'); gpio.on('change', ...
1
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0answers
59 views

Raspberry Pi has no GPIO Output

my raspberry pi 3B+ hast the latest Buster Update(Installed 23.03.2020). When I measure the GPIO output I get with at the 5V pin around 0.025V of output and at the 3V pin the multimeter says 0V. I ...
4
votes
3answers
2k 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: ...
1
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1answer
192 views

powering a sensor usin external power

I' m not electronic or electricity specialist , i'm a developer who tries to make fun stuff on raspberry pi , and this is why i burned two rpi 3 . i'm using my rpi with many electronic stuff , pir ...
0
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0answers
36 views

Can GPIO pin of Raspberry pi tolerate voltage above 3.3V? [duplicate]

I am using an inductive proximity sensor having an operating voltage of 5V with raspberry pi 3B+. Sensor has been given 5V from Pi. On sensing metal, output of this sensor is approximately 4.5-5Volts. ...
1
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0answers
93 views

RPi 4B official power source not powering it ON

I am trying to get my RPi4B(4GB) powered ON with a power supply but am frustrated with the results. I found a workaround to this problem, which is that I can power on the Pi4B with a type-C USB cable ...