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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 ...

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23 views

Interface a Raspberry Pi to a 4.3" TFT Display

How do I interface this 4.3" TFT display from FocusLCDs.com (https://focuslcds.com/product/4-3-tft-display-resistive-tp-e43rg34827lw2m300-r) to a Raspberry Pi? Do I need additional hardware? Code ...
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1answer
90 views

Debugging I2C, Effect of Oscilloscope Probes

Working on a simple I2C setup: Raspberry Pi connected to a WM8731 audio chip. The Raspberry Pi configures the WM8731 (which is write only) over I2C. Problem is WM8731 doesn't always respond with ...
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1answer
81 views

Communication between a Computer and Microcomputers

I am currently working on a project that require me to communicate between several Raspberry Pi's and a computer. I'll display data that sent by Raspberry Pi on that computer. Since I am using ...
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1answer
78 views

PC to Rasberry Pi Serial Communication

Im trying to communicate to my pc using my raspberry pi using a software called Docklight. I'm using a serial cable (that i ripped apart) and my breadboard as shown below. Now, you can also see I ...
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0answers
21 views

Powering on ESC causes backfeeding on PWM line

This question is on behalf of the robotics team I am a part of. Our robot's electrical system has been working great. However, we noticed that once in a while our Teensy or Raspberry PI would crash ...
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1answer
104 views

Fast, cheap, wireless data transmission with Raspberry Pi [closed]

I need some advice on a project. I want to wirelessly transmit packets of data from a Raspberry Pi to several microcontrollers (Arduino or other). The frequency must be at least 15 packets/s per ...
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1answer
86 views

2 Computers 1 USB Device (circuit help) [on hold]

I have a project with a custom USB device that pumps out a stream of data every 1.125 seconds to a Raspberry Pi running Windows 10 IoT, and occasionally receives an 8-byte command. The USB device and ...
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5answers
73 views

How to measure voltage of a floating GPIO (Raspberry Pi)

I would like to measure that voltage of a floating GPIO on a Raspberry Pi 3. When I use a multi meter or an oscilloscope it looks like the pin is pulled to ground and shows 0. Another way of asking ...
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1answer
23 views

Can I add an INA219 voltage\current sensor to this USB powerbank?

I have a Raspberry Pi Zero in a small robot that I have been powering off a USB powerbank and it works great. Unfortunately when the USB battery goes flat the power is cut and the Pi crashes. I want ...
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3answers
92 views

Using Raspberry Pi to turn TV on and off directly (not using infrared) [on hold]

I am creating a device that requires a TV to be powered on and off when commanded by the code in my Raspberry Pi 3 B+. The Raspberry Pi also needs some sensing ability to know if the TV is on or off, ...
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0answers
40 views

Sharing a 5v Supply

I want to deploy a Pi Zero in a weatherproof box. I need to provide 5v DC for the Pi and an 8 channel Relay Board and two 5v DC pumps. I have a 5VDC 5A 25W single output power supply that seems ...
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29 views

Using a raspberry pi screen for a beaglebone black

I am currently trying to use a touch screen (XPT2046 Touch controller 3.5 inch RPi Display), usually made for a raspberry, for my beagleboard black. I have installed everything on my raspberry already ...
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2answers
1k views

How to connect an industrial 24V sensor to a 3.3V input Raspberry Pi pin?

Background I want to read how efficient an industrial manufacturing line is without tampering with the PLC code. The simplest solution I can think of is using a Raspberry Pi, thus creating an ...
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2answers
52 views

Motor driver chips only work one time?

I have the following chip (DRV8833) Technical documentation The inputs work the following way And i have connected it the following way (I think) simulate this circuit – Schematic created ...
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2answers
52 views

Relay switching a light causes a spike, making a raspberry pi halt

The problem in short: I worry that switching lights is causing a spike. Occasionally a Raspberry Pi halts completely after a relay is switched. The setup: A Raspberry Pi 3 is connected to an ...
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1answer
64 views

Conflict of polarity?

With the following circuit, would the R2 resistor not change or affect the polarity in some negative way (no pun intended)? In the image below I added the red box as well as the red text in an effort ...
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0answers
37 views

Wiring of a passthrough charging circuit; confused about having a charger, a rechargeable battery and a load in the same circuit

General info To power a Raspberry Pi Zero device I’m working on, I need some high-capacity rechargeable battery with “passthrough charging” or “load sharing” (feel free to correct me if I’m wrong in ...
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1answer
51 views

Can I safely connect 20 Raspberry Pi Zeros to this 5V 10A power adapter

I want to connect 20 Raspberry Pi Zeros (5V, .200-.300A) to a 5V 10A power supply shown below. The setup Im planning will look like the photo below but with many more Raspberry Pis. I posted my setup ...
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1answer
29 views

Logic Level Converter (3.3v <-> 5.0v) returning HIGH for Low Volt. & High Volt. sides when nothing is plugged in. [Raspberry Pi]

The Goal I have a Raspberry Pi that I'd like to control my treadmill with. The Pi's GPIO ports output 3.3v and the treadmill's motor control board only takes 5v signals. Because of that, I bought a ...
3
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1answer
106 views

SPI comunication - Only receive 0xFF (Linux)

I've been stuck in setting up the SPI communication in Linux and can't figure out any solution. I working with a beagle bone black, which runs Linux. I have a piece of code that send data through the ...
2
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1answer
50 views

Repairing my FFC connector - what to use? [closed]

I'm using a Pi Camera v2.1 and a 15-pin FFC My 150mm, 15-pin Flat Flax Connector (on 1 side) has 1 pin slightly shortened (metal torn). My Raspberry Pi 3 is not working with it. What should I do: ...
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1answer
48 views

Two 5V Raspberry Pi UPS Idea

I need a cheap, reliable and easy to build UPS for my raspberry pi server. The UPS must maintain power for a maximum of 1 hour. Based on what I found on the internet,I came with two solution. (see ...
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0answers
9 views

RPi & VisualGDB - running GUI application [migrated]

I am trying to run application compiled in VisualGDB on my Raspberry Pi. In Visual Studio debugging works fine, but I need to run this application on HDMI monitor. I tried to run the file on RPi, ...
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2answers
71 views

Raspberry Pi driving a LED through a MOSFET

I need to control a LED with a Raspberry Pi! The LED is a white one and it has to be PWM driven, in order to make it show a sort of "breathing effect". Unfortunately I don't have the LED datasheet ...
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0answers
36 views

Undervoltage/capacitor problems with Raspberry Pi

My question is about the correct way to add a capacitor to a circuit with a Raspberry Pi driving a servo. I have seen undervoltage events in the logs of my app when the servo runs so I added a 470uF/...
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1answer
68 views

Which Board Should I Use For High Frequency GPS?

This is a very general question, hopefully with the amount of information I provide you will be able to steer me in the right direction. I am trying to build a very versatile GPS receiver, with ...
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1answer
81 views

INA219 measure voltage of battery with RPi

simulate this circuit – Schematic created using CircuitLab I want to measure voltage of 12V battery powering something by INA219 connected parallel to this battery and read it with RPi via I2C. ...
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1answer
134 views

How to reduce voltage with no earth?

I'm currently working with raspberry pi's that are going to be powered through an LED night light (its for being able to observe people working on experiments and giving light to the camera) and in ...
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0answers
36 views

Does a pin (input pin arduino) still float when connected to GPIO on RPI? [migrated]

I am currently testing my application on an arduino, and I experience floating pin issues. My program reads the pin status of input pins, which are configured as ...
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2answers
65 views

What VBAT lines do I really need in this schematic? - Recharge battery & Check battery level

So I'm currently using the design & schematic of adafruit's Powerboost 1000c. I've already discovered in a previous thread about which VBUS lines I can remove but will have to find out what I need ...
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0answers
21 views

MEMS microphone with custom frequency filter

How do I make a custom frequency-filtered (i.e. 25k-30kHz) microphone that is compatible with Rpi3 or Arduino. I found many mems microphones online that are all fixed frequency range, but none seem ...
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4answers
2k views

Detect 220 VAC with a Raspberry Pi

I want to build a simple device to check if the light is on or off. I found some schematics but I need to be sure that it is safe. Source : How to detect 220 VAC voltage using an opto-isolator My ...
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0answers
62 views

Trouble interfacing with this LCD. Why do I need SPI to make it work?

I'm trying to create my own version of an HDMI decoder board from Adafruit to work with an IPS screen that I have to work with a Raspberry Pi. The pinouts on my screen match almost exactly to the ...
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0answers
47 views

RPI - How can I access IDE via USB micro | Do I need VBUS later in my design?

I'm using the Raspberry Pi Compute Module 3 in a custom PCB and upon assembling the boards, I spotted a rather annoying mistake: the only way I can connect to the RPI IDE in order to program would be ...
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2answers
58 views

Shutdown amplifier when headphones are connected

I'm designing a board for a diy synth, one of the circuits consists in a audio amplifier that drives a small 1W speaker. The amplifier takes the signals from a Raspberry hat(a Fe-Pi Audio V2) and I ...
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3answers
64 views

Constant Current LED Driver with Raspberry Pi Zero W

I have a 12 V DC source that I'm wanting to run a Raspberry Pi Zero and a couple of 3 W IR LEDs. I'm not using the Pi to control the LEDs in any way. The LEDs are just to provide lighting at night ...
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1answer
45 views

How to stabilise SPI connection

To salvage a server with a broken BIOS, I am attempting to in-situ program a chip via SPI using a Raspberry Pi 3B: After connecting my clip and wiring it up (and measuring all the leads to ensure I ...
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1answer
39 views

Slew Rate controlled MOSFET switch

This circuit controls the rate at which M1 switches on using the current mirror consisting of Q1 and Q2. A digital pot is used to control the current through Q2. The circuit works great in simulation, ...
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2answers
136 views

Can't get low pulse from particulate sensor Shinyei PPD42

I have a Shinyei PPD42 that's connected to my Raspberry Pi B+ using a voltage divider to get the output of the PPD42 to 3.3 V. According to the specification sheet, P1 emits digital output when >1 μm ...
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1answer
54 views

Ammeter for 24V power that can be read by a Raspberry Pi?

I have a project I'm trying to design and build that involves a "more accurate/useful" battery gauge for an electric scooter. The scooter runs on 24V off of two AGM cells in series. The details of the ...
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0answers
27 views

Measuring vibrations of breathing

A newbie question. I have a somewhat unique idea that I am trying to understand if it is feasible or not. I would like to measure the vibrations of the nasal passage of the horse as it breathes at ...
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1answer
55 views

Connecting Lora and FSK clients to a single server

I need to connect a Raspberry Pi (as the server) to some different Arduino devices as clients. Some of the clients need to connect using Lora SX1278 modules, and others use NRF24L01+ (or any similar ...
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0answers
44 views

Digital IR Distance Sensor - Too Sensitive

I am building a few productivity timers that will be used on an assembly line to track the pace of operators as they work. The assembly line consists of a long frame with rollers spaced every 6 inches....
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1answer
79 views

Mini UPS schematic question

I found the following schematic for a rudimentary mini UPS: (Original source website) and in the description on the original website (link above) it says: D2 → Prevents backfeeding of 5v wall ...
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1answer
87 views

Is it possible to use a raspberry pi to control these LED strips?

I want to control some LED strips (inside PVC tubes) with a raspberry pi. Is this possible? Where would I start? The problems are, I don't have a lot of info about the strips: LED Chip Model:SMD5050 ...
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1answer
49 views

How to reduce noise in this circuit?

I'm using a Raspberry Pi in a circuit I'm building that includes a few elements. Elements in the circuit: PWM driver to control 3 servos Mic board for recording Class D Amplifier that drives 2x3W ...
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1answer
112 views

Is there any single-board computer/system-on-a-chip with good documentation for developing bare metal? [closed]

I always wanted to develop my own crappy operating system, but the many weird legacy quirks of the x86/PC platform kept me from doing so (e.g. real vs protected mode, only low resolutions available in ...
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1answer
55 views

Sensors to detect inside liquids temperature and percentage of alcohol

I would like to measure and study the correlation between temperature and percentage of alcohol inside a bin with fermenting beer, what type of sensor do I need. I was planning to plug this sensors ...
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2answers
70 views

Need help building circuit for 5V-12V Voltage regulation of external 12V power-source via PWM-GPIO of Raspberry Pi

I have a project, where a raspberry-pi shall measure temperature, and regulate a 12V non-pwm fan by modifying voltage throughput to the fan between 5V and 12V. The fan has a separate power-supply. ...
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0answers
30 views

Using two motor drivers to control a single stepper motor

For this project, I am running a single, small (6mm di.) stepper motor. I require the full power available from the first driver to provide enough torque to rotate the motor’s gear. The problem is ...