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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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860 views

How to use RPI 2 to debug RPI model B via JTAG with OpenOCD

I have a RPI 2 that I want to use for programming and debugging a RPI model B over JTAG for a bare metal project. Right now I'm having trouble to get the two boards to even talk to each other over ...
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2k views

How to fix RaspberryPi HDMI-DDC/CEC issue while keeping ESD protection?

The RaspberryPi (Type B, all revisions before B+) shows a more or less well known issue with the CEC/DDC of connected HDMI devices. When powered down CEC between the connected TV set and other devices ...
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137 views

Can't get L293D to work with raspberry pi zero w

I have the following When i turn GPIO 17: high GPIO 22: high GPIO 27: low or GPIO 17: low GPIO 22: high GPIO 27: high ...
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416 views

Is it possible to make a Raspberry Pi transmit FM on several frequencies at the same time?

I have read a few questions here on transmitting on multiple frequencies at the same time. But all of them was about transmitting the same signal to all frequencies. The PiFM and PiTX projects are ...
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1k views

L293D 2 Phase Bipolar Stepper Motor

I have an M35SP-11NK stepper motor that I would like to be able to drive with an L293D driver chip. The circuit below is how I've got it wired up so far. I've derived this from numerous sources on the ...
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38 views

Why does my GPIO only show 2V when connected to the Gate Termina lof NTE2390?

I've got a circuit set up with a motor that matches this diagram. When a 3 V power supply is connected to the Gate terminal, the motor spins. However, when I replace the 3V supply at the Gate ...
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34 views

Flashing firmware using RPi3

I have been trying to flash firmware onto the PC Engines APU2 platform. I'm using an SPI interface. RPi3's SPI is hooked up to the three-state quad buffer SN74LV125AD. For now, it is just a proof of ...
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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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22 views

high pincount stackable header separation

I recently made myself a custom hat for a Raspberry Pi. To connect the Pi and the Hat there is a 2x20 stackable header. However, I find it extremely difficult to separate them once they are mated ...
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89 views

Turn ON/OFF 5V 2-5A by Raspberry Pi GPIO

I need to control few 5V 2-5A devices by rpi GPIOs, which has the 3.3V logic level. I come up with a simple circuit, but I'll appreciate any ideas, corrections, suggestions. The LOAD is something like ...
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118 views

Dac over raspberry pi spi troubleshooting

I am trying to output a signal with dac124s085 from python code on a raspberry pi 3b, running Raspbian Stretch (kernel 4.14.30-v7+ #1102). I am sure the spi master driver is enabled - dtparam=spi=on ...
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40 views

LAN9512 keeps disconnecting from RPi Compute Module

Main problem I'm using a RPi CM and I connected a LAN9512 to it. However it keeps disconnecting: ...
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146 views

Low frequency PWM Brushless DC Motor Speed Control

I am programming a L293D motor driver with a BLDC motor to spin at speeds of 60-300 RPM. It is for a hybrid drone/car where I want the motors to spin slowly while having the necessary torque to drive. ...
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129 views

NiMH Smart Charging Circuit with Load-Share for Autonomous Robot

a couple of questions/issues for creating a NiMH smart charging circuit with load-sharing. Background I have a functional autonomous robot based on different MCU including Arduinos and a Raspberry ...
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310 views

How to control l298n voltage output

Recently I've been working on an RC car controlled by a Raspberry pi mounted on an RC car and connected to 2 motors via l298n dual h-bridge and im using a 12V battery to power the l298N However it ...
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87 views

Mini HDMI female - is one pin supposed to be shorter?

I have a Raspberry Pi Zero with Mini HDMI output. I acts kinda weirdly - it does work with a TV with HDMI input, but when plugged into a monitor with DVI input (with an appropriate HDMI>DVI cable) it ...
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117 views

OpAmp Clipping? Issues

I am trying to amplify a simple 120mVPP sine wave (4K Hz) to a 5VPP signal being made by an AD9850 being controlled by a raspberry pi. We started off using a 741 but realized after asking you guys ...
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175 views

Problem with Pyserial read time

I'm building a RS485 network with rpi3 as master and a bunch of c51 mcu as slaves. After sending an address, the master waits for the slave to respond and then starts to send data. I'm using Pyserial ...
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142 views

Hard on/off switch RPI with graceful shutdown

I am building a WiFI solution for a DSLR camera; so after connecting you can view the image via a webbrowser. For this I gutted a so called battery 'grip', which has buttons with which normally you ...
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141 views

Raspberry Pi controlling DC motor with 2N2222A

I'm new with the RasPi and I'm trying to build an automated irrigation system. The code is ok because it does what I want, it takes measurements of water content and when it's low, it changes one ...
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291 views

How to remove noise between raspberry pi PWM0 and SIM800L mic pin?

In my project SIM800L module(GSM Module) is interfaced with raspberry pi zero. Whenever user call Pi zero play an audio so that user can hear it. To send audio signal from pi zero to SIM800L, PWM0 pin ...
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90 views

MOSFETs are dimming my LED lights - checked other threads but it doesn't work

I'm trying to make an LED strip that I bought off Amazon work with my Raspberry Pi. It works just fine when I connect it through the included adapter which I took apart (shown below): However, it is ...
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60 views

High pitched feedback or interference in system with amplifier and Raspberry Pi

I have a system running on 12V currently provided by a current-limiting power supply. In parallel this source feeds an amplifier and a 12V to 5V transformer. The 5V transformer directly feeds a ...
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360 views

Controlling the GND rail

Okay so I'm running into trouble with my small setup, and I'm not sure how to go from here. I've drawn up a very (terrible) schematic of what I currently have wired up: So currently, I have 12v ...
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167 views

Software flashing attiny167 from RPi with avrdude

I am trying to flash a program onto an attiny167 (already bootloaded with the micronucleus bootloader) with a Raspberry Pi via avrdude and USB. Background I have 50 Raspberry Pi 3B's connected to an ...
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52 views

Host device data transfer to 10 slave devices

I have a project I'd like to prototype that requires a host device that can communicate with up to 10 small hand-held slaves at one time. I looked at the latest Raspberry Pi 3 and it may possibly ...
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141 views

Does pixel binning mitigate the rolling shutter effect?

Does pixel binning help to mitigate the rolling shutter effect of a full resolution capture? The idea behind this would be that when binned there is fewer data for readout and thus the image readout ...
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454 views

make an LED blink on rpi2 in assembly

I am trying to make an LED blink on assembly on my raspberry pi 2 model B to debug some startup code. However I don't see anything blink. Could someone tell me what I am forgetting? ...
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1k views

LCD driver board M.NT68676.2 issue: Screen compressed, fills only part of display

I am trying to build a portable Raspberry Pi/Retropie system with an LCD screen I got from my old laptop (the idea is to have a portable gaming console to be used in a car). To drive the screen, I am ...
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794 views

Powering a Raspberry Pi Rover with Lithium Ion Batteries and Charging Them

I am working on a 4 wheeled rover project. As the rover needs to be operated remotely, I will need some sort of batteries onboard. The major parts that need to be powered by the batteries are: ...
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496 views

3 Phase power logger with ADC and Raspberry Pi

I am building a 3 phase power logger with the ability to measure 3-phase AC and 2 DC inputs as well for a final year project. A typical application would be measuring a small inverter for a solar ...
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271 views

Relay module not working

I bought this relay module and I tried connecting it to my raspberry pi. I attached the Vcc (one next to the inputs) to the 5v rail of the pi and gnd to gnd. I attached the input pins to various gpio ...
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185 views

Raspberry pi B+ internal power supply ckt?

I have just started to study about raspberry pi B+ (data sheet) Can somebody explain the working of power supply circuit (individual component wise) starting from pg 14. How and why it is ...
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145 views

Raspberry Pi parallel power

I have wired up 4 Raspberry Pis in parallel, each being activated by its own SPST toggle. The circuit is being powered by a 5V 5A switching power supply. Each time I power on a pi after the initial, ...
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659 views

USB battery charger and GPIO power supply schematic for Raspberry Pi

I'm trying to design a circuit in Eagle to provide reliable + safe battery power to a Raspberry Pi via the GPIO pins. The requirements are: Accept power input via micro USB (separate from the Pi). ...
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1k views

RFID race timing system using raspberry Pi?

I would like to build a race timing system using UHF RFID passive tags. I have seen self build systems described as per the following link which is being used in races with apparent success: http://...
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2k views

How do I connect a photodiode to a GPIO?

I'm trying to read serial data emitted through an IR led with a Raspberry Pi using an IR photodiode, but I'm not sure about the correct way to hook it up. Unfortunately I don't have a part number for ...
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230 views

Problems with Infrared circuit on a PCB - Is it the board or schematic?

I am using the toner transfer method to apply my circuit for 6 sets of infrared emitters and collectors connected to an RJ15 cable on a PCB for use with a Raspberry Pi B+ board (connected via IDE ...
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991 views

ADC input to raspberry pi - I2C vs I2S

I'm trying to create a microphone array and take readings into a raspberry pi. I'm having an 8 bit ADC connected to the pi via I2C (SCL and SDA pins). I'm able to read samples (0-255) into my pi using ...
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69 views

Capacitive where is the touch?

I am a newbie in the world of circuits and electronics. But we all started somewhere. I have this idea about a street sign that should be used as an instrument. All most like a Theremin. Touching it ...
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2k views

Detecting vehicle on parking spot

For a project we're working on we need to detect if a car is standing on a parking spot. We're using an ultrasonic sensor for this, SRF05. While using the correct timings we can only sense for about a ...
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205 views

MOSFET to be switched by a raspberry pi

My raspberry pi produces a 3.3V on it's GPIO. I want to buy a through hole MOSFET so I can simulate touch-events on a smartphone screen like this video. I'm trying to find something on Digi-Key, but I'...
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297 views

XBee module lockup/freeze

I am using Xbee series 2 modules to handle communications between my home automation modules. As my base station, I am using Raspberry PI with Xbee coordinator attached to it. It all seems to be ...
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361 views

What is the best way to take multiple near-simultaneous pictures from 6 cameras on a development board?

I thought I could use a powered usb hub, connect the 6 cameras to it, connect the hub to the raspberry pi and capture the images one after the other quickly using the motion package. But I can't find ...
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1k views

Raspberry Pi with SMBus SmartBattery

I'm trying to interface a Raspberry Pi with the mini-box OpenUPS. It claims to implement the Smart Battery SMBus specifications. I can read data from the device using the i2c_smbus_read_word_data() ...
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36 views

I used a compression load cell, a HX711 and a Raspberry and I get really terrible inconsistent readings, are these devices incompitable?

I wanted to create a 10-200 lbs scale using a FX1901-200 lbs load cell (https://www.digikey.ch/product-detail/en/te-connectivity-measurement-specialties/FX1901-0001-0200-L/223-1531-ND/5277314), a ...
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34 views

MCP 3008 Re: Raspberry pi

I am new to circuitry. Naturally, this presents a few problems when asking a question: One often does not know enough to formulate a well-formed question. My apologies in advance. I use a ...
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0answers
60 views

How to deal with long distance I2C

I have 8 SRF02 ultrasonic rangers connected into I2C bus. They have to be integrated into a robot of dimensions 600mm x 800mm (for safety system purpose). I tested the setup on a breadboard with ...
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0answers
12 views

OSError: [Errno 121] Remote I/O error or pigpio.error: 'I2C read failed' on MPU6050

So I use MPU6050 to get acceleration from stepper motor linear rail movement(steper motor working in thread, I use pigpio for the motor) by make the MPU6050 can work on threading and it can show data ...
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45 views

Serial communication between raspberry and laptop not giving right values

I want to communicate between a Raspberry Pi 3 model B and a laptop using a USB to RS-232 cable and this RS-232 to 3.3V TTL converter via the serial module in Python: GND is connected to board pin #6 ...