Questions tagged [electronics]

Use this tag for questions related to how to use control electronics from the Raspberry Pi, and how to control the Raspberry Pi from electronics.

4
votes
2answers
91 views

Are resistors required for builtin PWM fans?

There are many guides on how to set up a 5V fan for a Raspberry Pi and control its speed with PWM. Usually, this includes using a a transistor a resistor between the PWM pin and the transistor gate ...
1
vote
2answers
45 views

What's wrong with my current calculation for an LED panel?

I am trying to understand how much current is required for one LED matrix panel, however, I don't quite understand it in general. Take this panel as an example. This is an 64x32 LED matrix, and its ...
1
vote
1answer
33 views

Is a RC snubber required when using the pi with a relay?

I am hoping to use raspberry pi to switch on and off a heating lamp and an aquarium pump via a relay switch. Both devices are plugged into 120V AC normally. The relay tutorials online seem to be ...
2
votes
1answer
44 views

i2c-bus electrically damaged due to wrong wiring

In a hurry I mistakenly connected the VCC of the Bmp280 to ground and the ground of the Bmp280 to 5V. Afterwards, I checked the i2c-bus with another sensor but i2cdetect -y 1 only reported --. Q How ...
1
vote
3answers
89 views

Can a relay be on for 16 hours continuously?

A part of my engineering project involves a L.E.D tubelight staying on for 16 hours continuously. I am connecting the light to a relay module. Is it ok, if the relay stays on for so long? I mean, is ...
0
votes
1answer
104 views

Connecting 4 HX711 to one Raspberry Pi

I have four individual scales that are each connected to a HX711, those HX711s are each connected to the Raspberry Pi. I'm a beginner in python as well as this Rasberry Pi. how do i properly code this ...
1
vote
1answer
28 views

control mecanno 4.7v motor with pi

I am trying to build an RC car and in order to make it work I want to control the motor with my pi.. The motor is Meccano Part #D469, a 4.7v motor. If I have this: https://www.ebay.com/itm/Adafruit-...
0
votes
0answers
60 views

L298N not working anymore

This is an image of how I had it routed up, it was working just fine until I attempted to add a rocker switch. I used the 2 pin on/off rocker switch that came with my smart car kit (https://www.ebay....
-1
votes
1answer
49 views

Powering a line following robot with a power bank. Any thoughts?

I am currently wondering for a college project, if it'd be possible or not to use a power bank to build a line following robot and power both the pi 3b+, the waveform motor driver hat with 2 dc motors(...
0
votes
0answers
23 views

Reusing old laptop speakers [duplicate]

The speakers are salvaged from an old Toshiba mini nb520 laptop. How could I go forward to use these speakers? Will I have to write my own drivers? Will it be worth the work? What electronic ...
0
votes
1answer
33 views

LED matrix won't light up properly

As you can see it won't light up correctly, why is it so? Is it possible that there are some issues with common cathode or anode? I tried using just that smaller one by itself, in a similar fashion ...
0
votes
2answers
77 views

How to know if Raspberry is running

I'd like to implement an electronic circuit to be able to restart my raspberry Pi when it has been shutdown (without plugging in and out the USB charger, which will obviously remain plugged all the ...
0
votes
0answers
75 views

Multiple raspberry pi's 3 synchronized image navigation

We have 7 raspberry pi's 3, each connected to the internet and an display. On each screen / raspberry pi is geeqie (image viewer_ running with an image slideshow. The goal is to have all raspberry pi'...
1
vote
0answers
42 views

I2C pin states when RPi powered off

I have a setup where RPi may join existing I2C -bus as master when powered on. Before taking over, it will first notify secondary master with "slave select" -line so that the bus becomes free for ...
1
vote
1answer
87 views

What can I use to detect a certain resitance and then have it send a signal to the gpio

I have bought a FlexiForce force sensitive resistor, which can measure weights from 1-100lbs with a driving voltage of 5V (although I plan on adjusting the range to 10-300 by setting the voltage to 0....
1
vote
1answer
115 views

same GPIO input signal on multiple raspberri's from one source

Im having 7 raspberri pi's 3 connected to 7 screens, running an python 2.7 app to download different images from google drive, every raspberry has different images. Geeqie is displaying those images ...
0
votes
1answer
42 views

Can it damage my Pi to permanently pull down the RUN pin?

I have a use-case where I would leave my Raspberry Pi powered up but keep it in the halted state by pulling down the RUN pinout. Is this safe to do? Edit: The answer shows me that I did not state my ...
1
vote
0answers
46 views

How to extend battery life on custom pi laptop

So I'm trying to make a pi laptop based on this project with a few differences: I use this display instead of this Technically, I'm using 18650 cells, but at a slightly reduced capacity No Arduinos ...
1
vote
1answer
43 views

Controlling electromagnets in clock display

I have an electromechanical 7-segment clock display with each segment controlled by an electromagnet. A segment is 'on' depending on the polarity of the last pulse to its electromagnet. Can anyone ...
0
votes
1answer
217 views

Do I need a resistor for a 3v3 led? [duplicate]

Begginer question, if the output voltage of the raspberry pi is 3.3v and my led voltage is 3.3v, do I still need a resistor? As far as I understand, if the voltage is the same you don't need to add a ...
0
votes
1answer
184 views

Raspberry Pi Zero W - freezes after switching a relay connected to an AC motor [closed]

I'm working on a home IOT using Rpi to run script that controls opening/ closing window's shade ( switching its electric motor up or down ). 1) Code is very simple and working fine - switching gpio "...
0
votes
0answers
27 views

raspberry multiple magnetix switches

I have a Pi 2 and I would like to monitor the state of 3 magnetic switches. All of them are in close distance, no more than 3m of cabling for each one of them. How can I connect them to monitor their ...
1
vote
1answer
80 views

Raspberry Pi 3B ripped off resistor (C187)

I need help on my Raspberry Pi 3B. I accidentally broke a small part of it and it fell on the ground which is the reason I cannot find it anymore (It's just sooo small.). That is an image of the Rpi ...
0
votes
1answer
337 views

How to get positive and negative voltage for my circuit from a Raspberry Pi?

I am trying to connect a circuit which needs a +5 V and -5 V input. How can I get both voltages from a Raspberry Pi?
0
votes
1answer
192 views

Cracking sound on Speaker connected to USB Soundcard

I have connected speaker on USB sound Card with PAM8403 Amplifier before speaker to amplify sound on Raspberry Pi Zero W. I get constant cracking sound coming from it. I have connected 3.3V as VCC on ...
0
votes
1answer
75 views

rpi BMC power/reset trigger with GPIO

i m thinking about building a BMC using a raspberry. So i need to simulate power and reset button press using the GPIO. I would like to know if a transistor is suitable for this application and if ...
0
votes
1answer
565 views

How to wire an HC-SR04 without a breadboard?

I have a Raspberry Pi and a HC-SR04 integrated circuit for measuring distance. I have found many resources for how to connect the HC-SR04 to the GPIO of the Raspberry Pi, but because the HC-SR04 ...
0
votes
0answers
205 views

How to connect sensor to Raspi via poor man’s a/d converter?

TL/DR: I’m using this and there are things I don’t understand about this circuit. Ultimately I’d like to read data from this sensor, but all I get is gibberish. Please, help. I have set up “poor man’...
-1
votes
1answer
31 views

Turning It On and Off

I just bought a raspberry pi 3 on eBay that came with all the games. I can't get it to turn on. I have the power source plugged into the wall and the cdmi is in the tv. How do I turn it on? Do I ...
1
vote
3answers
92 views

How to electrically discharge myself before touching the Rpi? [closed]

I have seen here that I should discharge myself electrically before touching the RPi? The presenter suggests a bare metal water pipe. I don't have this at hand. Are there other ways I can discharge ...
1
vote
1answer
431 views

Transistor Switch: Turning off Waveshare LED Boards

This is a similar question to How to turn off the CSI, and turn it back on again, but I'm actually trying to implement the suggestions that were given in that post. I use the WaveShare RPi IR-CUT ...
0
votes
1answer
43 views

What will happen if I put my ESC's BEC black wire to ground and yellow/white wire to 5v pin directly

I wanted to do some experiment with raspi, ESC and BLDC motor. I am able to run my motor using servo tester. But I was curious what will happen if I connect ESC's BEC to Raspi's GND and 5v output ...
1
vote
1answer
483 views

Decrease the sensitivity on Capacitive Touch breakout?

I have this capacitive touch sensor: https://learn.adafruit.com/adafruit-capacitive-touch-sensor-breakouts/overview And it is WAY too sensitive for my purpose. I want to have a conductive panel on a ...
0
votes
3answers
301 views

Powering an element that draws more current/voltage than GPIO can supply?

I'm a little over my head here and I'm hoping someone might be able to help. I'm trying to control this Heating Pad using Raspberry Pi GPIO pins, turning it on and off via GPIO. It takes 5V DC and ...
5
votes
3answers
4k 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 ...
0
votes
2answers
290 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 ...
2
votes
0answers
117 views

Raspberry Pi as a Hi-Fi component

After reading the following post, I was wondering if I could achieve something similar with my own setup. I do own an old Technics SL505. However the nasty part of this setup is that each components ...
0
votes
1answer
66 views

Flow of current in the circuit

I'm very new to electronics and raspberry pi and trying to follow this tutorial. When I check the circuit the resistor is connected between the ground and the LED to limit the amount of current that ...
1
vote
1answer
252 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 ...
1
vote
2answers
817 views

Power Raspberry Pi using two 3.7v Lipo batteries

I was having trouble while booting up my Raspberry Pi powered by LiPo batteries. Ignore the components inside the blue circle I am just connecting the batteries, the darlington transistor and the ...
1
vote
1answer
68 views

Power required to run multiple appliances at once

I have an electronics question. I am no electrician and am trying to build an alarm pi Mark2. Currently I have a 12v power supply running through a relay which the pi turns on and off to trigger my ...
1
vote
2answers
72 views

Calculating wiring and properties of a resistor for use with a pushbutton

Raspberry Pi 1 Model A here. I am planning on using this pushbutton in a hobby project that is very similar to this CamJam EduKit project. In that CamJam project link, on page 2, I see a simple ...
1
vote
2answers
81 views

RPi 1 Model A input/output pin ratings

RPi 1 Model A here. Brand new to RPi and electronics in general. I'm finding a hard time finding the exact voltage/current "ratings" for my model but the closest I could find was a comment under this ...
0
votes
2answers
2k views

Increase volume of Piezo Buzzer

I recently bought a 3-24V Piezo Electronic Tone Buzzer Alarm. I would however like to increase the volume. Bare in mind that my electronic knowledge is (unfortunately) at the very basic level of; find ...
0
votes
1answer
37 views

Raspberry Pi 1 Model A and Pushbuttons: Simple solution [closed]

I have a Raspberry Pi 1 Model A and am interested in attaching pushbuttons to its GPIO pins so that when you physically push the button, the button sends a signal to the GPIO pin that can then be ...
1
vote
1answer
38 views

Raspberry Pi 1 Model A and peripheral component compatibility

I have a Raspberry Pi 1 Model A and have a simple hobby project I'm tinkering with. I will have two pushbuttons (PB1 and PB2 respectively) wired to the GPIO pins, as well as a buzzer and an LED. The ...
0
votes
1answer
27 views

Model A and peripheral component compatibility

I have a Raspberry Pi 1 Model A and have a simple hobby project I'm tinkering with. I will have two pushbuttons (PB1 and PB2 respectively) wired to the GPIO pins, as well as a buzzer and an LED. The ...
-2
votes
1answer
83 views

How to get started with basic Raspberry Pi electronics?

I have received a RPi 3 kit as a gift with tons of sensors, cables, resistors, etc. I have managed to get the typical LED demo working by following literal instructions but I don't understand how to ...
0
votes
1answer
696 views

How to read data from an NI DAQ USB-6259?

I have a sensor for which I'm forced to use a NI DAQ to read data from. And I have a USB-6259 to do so. I don't want to connect the DAQ directly to my laptop because it has messed it up before. I ...
1
vote
2answers
78 views

Running 2 amp device off raspberry pi zero

I have a device that requires 2amps and 4.5 volts. I wanted to use a GPIO pin from the rpi zero to power this device and switch it on and off. I am not sure what circuit to use, I was thinking of a ...