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 your desktop PC does, like spreadsheets, word-processing and games. It also plays high-definition video. The design is based around a ...

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16 views

Cellphone batteries used for projects

I am building a project involving a raspberry pi. It is known that the RPi runs around an average of 700mA of current and our project would probably need a little over than 1A of current due to ...
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0answers
27 views

Extend the Ethernet port of raspberry pi [on hold]

I want to extend the Ethernet port of my pi using a short bit of cable plugges in into the pi and soldered to another rj45-jack. In the jack I have here, are some built-in coils ( looks like ...
2
votes
2answers
103 views

Controlling 10 high power LED with a Raspberry Pi

I'm trying to figure out how to control 10 Luxeon Rebel LED (700mA) from a Raspberry Pi. I want to be able to turn them on and off from code, but I don't need to have two or more LEDs turned on at ...
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0answers
26 views

TC358743XBG HDMI to CSI-2 Board

I've got a project in which I have video output from a camera which I can have in either video out or HDMI out. This signal, then, is to be sent to a Raspberry Pi to be used in a computer vision ...
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1answer
29 views

Xbee Serial communication with RaspberryPi - In Lua

We are working with Mihini for an IoT project. Here we have to communicate via Xbee with sensor nodes and coordinator(RaspberryPi) . Mihini doesn't seem to have any modules particular for Xbee ...
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2answers
50 views

MCP3008 alternative

I have some analog devices like LDR, temperature sensors, and other sensors and I want to use the readings of these sensors in my raspberry pi B+ , for that I need an ADC , to convert the analog ...
0
votes
1answer
32 views

Question about RFID Reader Frequency and RFID Tags

I'm researching about RFID Technology as i'm trying to build a RFID Reader using an Arduino and/or Raspberry Pi which i been trying to do so for a month however with no avail. So i been reading up as ...
2
votes
1answer
79 views

Understanding a SPI command sheet

I am interested in learning more about how SPI works in general, but with the raspberry pi and py-spidev library in mind. I am very technically savvy, although not so much on the EE side of things. I ...
3
votes
2answers
491 views

How long will a battery last based on these numbers

Hi I asked this question on SU but seemed to have gotten into a bit of trouble, I was referenced here. I am getting into doing hardware build based on things like microcontrollers and ...
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0answers
14 views

Assigning a Public IP for RaspberryPi in local area wired network [migrated]

We are trying to configure RaspberryPi with public IP (192.248.10.71) in local area wired network. This is the network configuration in /etc/network/interfaces, ...
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0answers
20 views

New Haven display On Raspberry Pi (NHD-C0220)

I'm here because I don't have experience connecting / wiring i2c devices to raspberry. I need to know how the correct way to wire this display to the gpio connector. Right now it's connected, but ...
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3answers
56 views

How does digital pullups work?

I have lame question. How does digital pullups work? I'm asking because I don't understand DHT11 driver code. Sample code: ...
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0answers
64 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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0answers
33 views

Ideas for powering multiple DC devices from Battery being charged from AC [closed]

I live in a place with regular power failure. A few hours every day. Was looking at getting a UPS, but most of my equipment is low power (5V-12V). So it's kind of silly to get a ups to up convert ...
1
vote
1answer
68 views

Does Ground Voltage Need Lowered As Well?

I am dividing voltage of a 9V battery to 3V for a Rasperry Pi GPIO. I have the ground connected to the end of the resistors, so it is back to 9V when I connect it to the Pi's ground pin. Is it ok to ...
0
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0answers
61 views

Building a UPS for Raspberry-Pi

I am trying to build a 5V/2A uninterrupted power supply (UPS) for my rPi B+ using LM7805 and some phone batteries (3.8V/0.5A and 3.7V/2A) or any of the 6 pcs 18650 batteries (3.7V/2A) that I have ...
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vote
1answer
33 views

problem with LED matrix and raspberry pi

I have a raspberry pi model B+ , and an 8x8 LED matrix(single colored) , so I connected 8 GPIO pins to the 8 row pins of the matrix and another 8 GPIO pins to the 8 colomn pins. Note that I am pretty ...
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3answers
75 views

(Beginner) Type of (NPN?) transistor to use for RasPi

I'm new to EE. I burned out a Raspberry Pi by running an electric motor directly from its GPIO pins, and then I learned about transistors. I now have another RasPi, but I'm not sure what transistors ...
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0answers
35 views

RFID card reader : wiegand 26 bits but UID tag 40 bits?

I am working on a project of access control with a Raspberry Pi. I want to buy a RFID card reader (125 khz) and tags. After a lot of research on the web, I found out that the most common connection ...
0
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0answers
23 views

What are the main differences between 4n25 and SFH6156-2T optocouplers?

I'm looking for a 4 pin surface mount equivalent to a 4n25 optocoupler. I'm really not sure what to look for when comparing the data sheets of each optocoupler and I want to try avoid purchasing the ...
1
vote
1answer
104 views

Connect lots sensors (more than 10, mostly accelerometers) to Raspberry Pi by using slaved Arduino solution

I am a programmer but quite new to electronics. I am trying to connect more than 16 sensors into a RaspberryPi for analysis, because I'm mainly focusing on computing science's machine learning ...
0
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1answer
62 views

XY-MK-5V suddenly stops working

I have a situation that just baffles me here... I bought these cheap XY-MK-5V RF receivers with FS1000A transmitters. I fitted the receiver to an Arduino UNO connected to an 8-channel relay board, ...
0
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1answer
74 views

How to communicate 'rawly' with an HD44780 compatible LCD?

I have a HD44780 compatible lcd display (QC1602A). I did a lot of research and found some helpful things, but none of then seemed to really have worked. I'm not using any lcd library (C), only the ...
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votes
2answers
58 views

Powering a rpi and accessory of a 9v battery [closed]

We are trying to use a raspberry pi to record the current going through a dc circuit. The circuit we are trying to measure the current in is powered by a car battery. We have no idea how to record the ...
1
vote
2answers
99 views

Is a relay with a 20 amp rating enough to handle the current from a residential hot water heater?

In Israel the houses usually have a hot water cylinder on the roof of the building which is attached to a solar water heating unit, but which also is connected to an electric heating element which is ...
0
votes
1answer
87 views

Connecting pins of Raspberry Pi GPIO in series in order to turn up the voltage

It's unorthodox and probably not recommended by anyone but, for my project of driving a relay only with scrap parts and on the cheap, I managed to get a 12v relay, but, the GPIO ports on the RPi only ...
1
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2answers
109 views

Power-Supply “Combination”: Solar for voltage + Battery for current

I'm rather new to circuits & DIY electronics, but am thoroughly enjoying tinkering with my new RaspberryPi and assorted components. I'm trying to power the device using a few simple solar panels I ...
0
votes
1answer
48 views

How to remove GPIO ribbon from raspberry pi

This is basically it. I got my new raspberry pi and I got a GPIO ribbon to connect it from the raspberry's GPIO's to a breadboard. Now I am trying to remove the ribbon from the raspberry by just ...
1
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0answers
29 views

Controlling Raspberry Pi GPIO using Javascript [closed]

I am familiarizing myself with the GPIO pins on the Raspberry pi and was wondering what the easiest way to control them would be using HTML and javascript over a webpage. My intent is to have a button ...
1
vote
1answer
68 views

Motor speed control mosfet

I have a Raspberry Pi and I want it to control DC motor speed. I make the pi output 3x3,3V for controlling the speed. I need circuit that works like this; when one output gives 3,3V motor have 6V, ...
1
vote
1answer
61 views

Raspberry Pi vs BeagleBone torrentbox [closed]

I'm planning to make an always on torrentbox, I get my internet from a 4g usb dongle modem, but I've very limited experience with such boards. From what I read on the internet, it seems BeagleBone is ...
0
votes
1answer
109 views

multi channel ac dimmer for arduino

I have been looking for a simple ac dimmer circuit to use with my arduino and/or raspberry pi. I have used the TLC 5940 PWM Driver before just to control LEDs and I wanted to adapt this to controlling ...
0
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0answers
48 views

Programmatically short GPIO pins Raspberry Pi

For a hobby I'm working on a project connecting a RF remote to the raspberry pi. When I press a button, pin 13 and 14 are shorted on the MCU. When I put a jumper cable between the pins, the remote ...
0
votes
2answers
82 views

nMOSFET not turning off properly using RPi GPIO pins

I have an N-Channel MOSFET (model: FQP30N06L) which I tried hooking up the Gate connector to a RaspberryPi GPIO pin (3.3v, also tried a always-on 5v). The Source connector connects to a wall-mounted ...
0
votes
0answers
47 views

Strange behavior Pin to GND

This morning I was trying to do some electronic engineering as a hobby. A few weeks ago I bought a wireless outlet with an RF remote. Right now I'm trying to connect the buttons of the RF remote to a ...
0
votes
1answer
87 views

RaspberryPi + TowardPro MG996R DIGI HI TORQUE +PWM

I am trying to control this servo from a RaspberryPi. https://skippy.org.uk/wp-content/uploads/MG996R_Tower-Pro.pdf I sort of figured out that a servo needs a specific pulse for a specific degree. ...
1
vote
1answer
111 views

Serial Link Between 3.3V devices

I have an RPi and a freescale FRDM-KL25z controller which will talk over serial protocol. I'm using the pyserial library on the pi: ...
1
vote
1answer
81 views

Output Units of Soil Moisture Sensor

I have an Octopus Soil Moisture Sensor connected to a Rasberry Pi through an MCP3008 ADC chip. The sensor is working correctly, but I have no idea what the reading values mean. I say its working ...
1
vote
5answers
195 views

Best way to get 256 io pins?

I'm connecting to an arduino or raspberry pi and would like to have 256 io pins. I found a 16bit io expander which has 8 unique addresses for 128 but that's the max I can do on i2c. Any other thoughts ...
2
votes
3answers
119 views

Reset the raspberry pi with a relay

I'm going to use my Rasp as a GPS tracking and it should be running even if the car is off; however, I don't want run out the car battery. To make it happens I added a battery controller ...
0
votes
0answers
40 views

Can I link Ethernet chips on PCB? [duplicate]

I read up on the Raspberry Pi Compute unit and wanted to link a hand full for networking. Unfortunately, they do not come with native Ethernet, but USB. So I was thinking of linking each compute ...
1
vote
1answer
115 views

H Bridge Control using Raspberry PI / Micro controller

I am looking for input on this circuit that I have designed. I am currently working on a project called the Net-EEL RC Car. It is an RC car that will be controllable using Network Socket Servers / ...
0
votes
0answers
43 views

Selecting relay for raspberry pi

I'm currently working on a raspberry pi project.In which i have to control four 30W 0.25A 230V Bulbs(which works using main 230V power supply) using output from GPIO pins.I'm a beginner in ...
0
votes
2answers
75 views

what do you connect to IN+ and IN- for ADC differential input configuration?

I was trying to understand how to read analog inputs on a raspberry pi. I found this video post and I think I understood how it works. https://www.youtube.com/watch?v=oW0mTwFck_c This video uses a ...
0
votes
1answer
71 views

3v Relay raspberry

I'm trying to drive a 3v Relay with a schematic like this: Relay is a HWE JRC-21F and transistor is a PN2222A instead of a BC337. This won't work unless I connect 3.3v directly to transistor base, ...
0
votes
0answers
208 views

LAN9512 USB hub and Ethernet Controller Problems

I'm working on a custom board using a Raspberry Pi computer on module (COM) (info and schematics here: http://www.raspberrypi.org/raspberry-pi-compute-module-new-product/. The board is based on the ...
1
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0answers
65 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 ...
1
vote
1answer
52 views

Help needed driving an old PIC programmer from Raspberry Pi GPIO

I have been trying to use a Raspberry Pi's GPIO pins to drive an old PIC programmer board that used to have a parallel port connection before I started messing about with it. You can see from the ...
0
votes
0answers
181 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 ...
5
votes
5answers
903 views

Safety of using microcontrollers such as Arduino

I have been learning how to work with Arduino Uno R3, and it seems very intuitive and exciting for me. As many agree, I see lots of benefits of learning to use it at a young age. I would like to ...