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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15 views

Delay between bytes using py-spidev for SPI communication on Raspberry Pi [migrated]

I am attempting to read/transfer data between an instrument and Raspberry pi 2, using the RPi as the Master and instrument as the slave. The data sheet states I must have a 9 ms delay between sending ...
2
votes
2answers
61 views

Is this the behavior of a broken mosfet?

I designed this circuit to switch on/off 8 solenoid valves for a programmable dancing fountain that I am building. The GPIO is coming from a Raspberry Pi. VCC is coming from a 12V deep cycle car ...
0
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3answers
75 views

Power Circuit for Raspberry pi portable

I am building a hand held portable raspberry pi. I have just plugging the battery in and using the thing, but I want to make the battery completely part of the unit without the need to unplug it when ...
1
vote
2answers
228 views

How do I work out what resistor to use?

I am trying to work out what resistor to use in a circuit. The circuit is a series circuit. The power to the circuit is 5.5V, with a switch, which connects to a GPIO pin on the RasberryPi. I believe ...
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1answer
49 views

Raspberry Pi B+ with relay: Lights change but relays don't click

I am using an 8 Relay module, bought from dx.com. It has no instruction manual... This board has 8 inputs (IN1,...,IN8) to control each relay, 1 VCC pin that requires 5V and 1 GND pin. I connected ...
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1answer
19 views

Controlling an ESC for Brushless Motors with an RPi

Originally posted on Robotics, but guess it's not active enough. I'm looking to build a new (first) quadcopter without the conventional flight controller and radio, with an onboard RPi and applying ...
0
votes
1answer
40 views

PoE Lower Signal Voltage

I'm currently working on a little project using a Raspberry Pi and an Ag9000-S. I've got it working using Mode A (phantom power over the data pairs) and Mode B (direct power over unused pairs), but ...
0
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0answers
43 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: ...
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1answer
30 views

ADC ic's for SPI protocol [closed]

I want to know what are the ADC Ic's is suitable for SPI protocol? because i cant find MCP3008 ic in shops? No one having this IC. Thanks.
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1answer
46 views

Darlington does not switch

I have a darlington Transistor circuit. Like in the schematic i attached. When i power up the 3V3 from my raspberry, the led is not on. When Doing Danke same with 12v instead of 5v, it Works ...
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1answer
42 views

DH-11 Sensor on a Raspberry Pi & Arduino

I am trying to make my DH-11 sensor work on my raspberry pi but I have not succeeded after several attempts. I followed the following tutorial from Adafruit: ...
0
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0answers
21 views

Creating a pulse when the circuit opened and closed [duplicate]

I would like to send wake up and halt signal to a linux board. I just want simulate the power button on the board so I will replace it with a circuit. So: When I the car's ignition line is on it has ...
0
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0answers
14 views

Can I connect my Innolux screen to Raspberry Pi 2 using TFP401 HDMI/DVI Decoder to 40-Pin TTL Breakout

Setup Raspberry Pi 2 TFP401 HDMI/DVI Decoder to 40-Pin TTL Breakout - Without Touch Innolux 5.6 LCM aSi TFT type LCD I am hoping to be able to connect the Pi2 to the Driver using a small HDMI ...
1
vote
1answer
57 views

Frequency Counting on a Raspberry PI

I am trying to count a square wave on a Raspberry PI. I tried a variety of approaches: http://abyz.co.uk/rpi/pigpio/examples.html (Freq counter 1 and 2) ...
1
vote
1answer
61 views

Voltage shift from 3.3V to 12V

I'd like to use MX-FS-03V 433MHz transmitter together with a Raspberry Pi (RPi). The Raspberry Pi's outputs have 3.3V, but the MX-FS-03V operates on 3.5-12V (the higher the voltage the higher the ...
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votes
3answers
91 views

Voltage shift from 5V to 3.3V

I'd like to use MX-05V 433MHz receiver together with a Raspberry Pi. The MX-05V operates on 5V, but the Raspberry Pi's inputs only allow 3.3V. So i need to shift the RX data output level from 5V to ...
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votes
2answers
52 views

Solderless headers?

Where can I find solderless headers suitable for a solderless breadboard.? This is for a raspberry pi project I'm working on which requires the mounting of an LCD screen. I have explored the ...
1
vote
2answers
159 views

Portable Batteries for the Raspberry Pi

I am building a project involving a Raspberry Pi. It is known that the RPi runs around an average of 700mA of current and my project would probably need a little over 1A of current due to attached ...
2
votes
2answers
153 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 ...
0
votes
0answers
84 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 ...
0
votes
1answer
59 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 ...
0
votes
2answers
75 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 ...
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votes
1answer
55 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
108 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
517 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
22 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 ...
0
votes
3answers
64 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: ...
1
vote
0answers
77 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 ...
1
vote
1answer
75 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
votes
0answers
75 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 ...
1
vote
1answer
54 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 ...
0
votes
3answers
82 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 ...
0
votes
0answers
70 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
votes
0answers
25 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
121 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
votes
1answer
85 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
votes
1answer
88 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 ...
-6
votes
2answers
60 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 ...
2
votes
2answers
111 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
96 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
vote
2answers
125 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
57 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
vote
0answers
40 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
83 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
70 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
137 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
votes
0answers
54 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
89 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
48 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
131 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. ...