Questions tagged [raspberry-pi]

The Raspberry Pi is a credit-card sized computer that plugs into your TV and a keyboard. There have been several generations of the device with improved performance, more memory, and more connectivity. This tag should be used for electrical engineering questions that involve the use of a Raspberry Pi. For questions about the Raspberry Pi itself see the Raspberry Pi specific forum (raspberrypi.stackexchange.com).

The Raspberry Pi is a single-board computer developed in the UK by the Raspberry Pi Foundation. The Raspberry Pi is a credit-card-sized computer that plugs into your TV and a keyboard.

It’s a capable little PC which can be used for many of the things that a desktop PC can do, like spreadsheets, word-processing, and games. It also plays high-definition video.

There are several generations of the Raspberry Pi, as well as several variants. More recent generations such as the Raspberry Pi 3 have faster processors and more capabilities such as WiFi and Bluetooth.

The processor used depends on the Pi generation, though all (as of 2017) are ARM processors. The design does not include a built-in hard disk or solid-state drive, instead relying on an SD card for booting and long-term storage. A self-powered drive connected through USB for large amounts of storage can also be used.

The standard operating system is Raspbian, a version of Linux, but other operating systems are available on later generations of the Pi (which have improved performance because of the processor used).

Note that SE has a Raspberry Pi site.

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Add a passive hardware token using a 3.5mm jack

I have a box that I made for my niece, which allows her to exchange voice messages with me. It is powered by a Raspberry Pi and features two buttons, a LED, a microphone and a speaker. Now, for Christmas I want my niece to be able to exchange these…
Besi
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Embedded Programming for Beginners: Arduino or Raspberry Pi?

I'm a computer science student and I'm eager to expand my knowledge on embedded programming and electrical engineering. I've read here that using tools like the Arduino microcontroller is a good way to start. I'm primarily a Java and Python…
Matthias Braun
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Understanding an 'ideal' diode made from a p-channel MOSFET and PNP transistors

The Raspberry Pi B+ models have a protection circuit between the USB connector and the 5V net on the board. They recommend putting a similar protection circuity on a Pi HAT before 'backpowering' the pi through its GPIO header along with a polyfuse.…
Mark Walker
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What does "no fit" mean in electronics?

I have found at some places, especially: Raspberry Pi Forums eLinux RPi Hardware page the following wording: S2: DSI interface. 15-pin surface mounted flat flex connector (possibly no-fit) S5: MIPI CSI-2 interface. 15-pin surface mounted flat…
dash17291
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How to properly use a relay module with JD-VCC from Arduino/Raspberry?

[EDIT] A quick benefit of JD-VCC, is that allows you to control the relays that are 5V with 3.3V GPIOs. Check the full answer to understand why :) [Original question] I got two 4-relay-modules and I am probably doing something wrong because none of…
Carlos Garcia
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Shutdown Controller for Raspberry Pi in a car

Following on from my previous question I'm trying to create a shutdown controller for my Raspberry Pi. The Raspberry Pi needs to be powered from the battery, but should power-down after the Pi detects that the ignition has been turned off. The Pi…
Nicholas Albion
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Is a pull up/down resistor really necessary?

Logical reading (1 or 0) of a micro-controller input GPIO pin may float if it is neither connected to VCC nor GND; someone said it is because of surrounding RF interference. When a floating GPIO input pin voltage is affected by RF interference that…
mannok
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Control the hardware of an old phone using a Raspberry PI

I have a very old phone (60 years old) and I want to control its part using a Raspberry PI: Microphone & speaker from the head set The bell The dial wheel I have the electric circuit but don't recognise all of the parts. My question is now how I…
Besi
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Raspberry PI without OS on it?

I've been doing a lot with Arduino recently. It's very simple because you can directly execute C++ code on it without the need of operating systems or drivers. I've done some research and AFAIK, you usually install Linux on the Raspberry PI and…
bytecode77
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Using a microcontroller to turn on LED strip

I have 60 leds that came in a led strip. One meter length of the led strip requires the following: 400 milliamps 12 volts I want to control these LEDs with micro controller. I'm thinking of using a TIP120 and a raspberryPi. A raspberryPi GPIO pin…
spuder
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Plugging a LDR into GPIO pins of a Raspberry Pi

I want to connect a LDR into the GPIO pins of my Raspberry Pi, I know that Raspberry Pi doesn't have an analog-to-digital converter so what I want to do is to signal a HIGH signal (3.3v) on the GPIO when there is low resistance on the LDR (something…
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shorting a remote control pushbutton with GPIO and a transistor

I'm trying to control my garage door remote with a GPIO pin from my Raspberry Pi. Instead of driving a relay, it would be much easier to just short the pushbutton on the remote. Is this how I should do it? Do I need a protection diode and if so,…
nummy
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Using a 5v voltage regulator - Capacitors necessary? Better options?

I am very new to electronics. I am learning as I go, and I haven't quite found the answers I need; when it comes to programming, I'm not afraid of mistakes as they happen constantly. With electronics, though, I don't want to have to buy parts again…
weildish
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Is the Raspberry Pi a microcontroller or a motherboard?

I had quick question regarding Raspberry Pi: is it a microcontroller or a motherboard? It looks like a motherboard, but considering that it has its own dedicated memory and processor, it should be a microcontroller.
alif
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I connect a 5 volts to a low resistance, but I measure a much lower current than I expect

I cannot understand why the current I expect is so different from what I am measuring. I found a very low resistor, 15 ohm and connect it to 5 volts. Why is the current I measure so low? Shouldn't it be 0.333 amperes? Obviously, I am a noob, but I…
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