GPIO stands for General Purpose Input Output and can be used to receive and send digital signals to and from simple electronics from the Raspberry Pi.
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Are there any sites dedicated to developing expansions for the GPIO port?
I am surprised on how there seems nothing developed for the input/output pin on the Raspberry Pi. So the question is, are there any sites (websites) that host projects of shields or similar for the ...
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1answer
61 views
Can executable code be run from the SD card without a bootloader?
I'm following Baking Pi and am just on lesson 1, which is the simple introductory ARMv6 code to turn on the OK LED on the Pi. I have compiled the code I've written and now the tutorial says to use an ...
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1answer
27 views
Connecting to an LCD via I2C
I'm trying to use a SainSmart 20x4 LCD connected via I2C.
I can manually drive pins 0 & 1 to high and low so I know they work.
I've commented the blacklist I2C-bcm2708 and blacklist SPI-bcm2708 ...
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2answers
29 views
How to output digital value to multiple GPIO pins as one port?
Is it possible to output integer binary values to GPIO pins at once like a parallel port?
I need that because I am afraid if I toggled pins one by one there will be invalid intermediate states that ...
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1answer
44 views
GPIO read volt input
lets assume i'm having a circut like this:
and (assuming Board mode)
Pin 2 would give me the 5V
Pin 6 = GND
Pin 3 = A0
how can i detect the input (Pin 3)? With python and RPi.GPIO i found only a ...
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2answers
25 views
Is it normal to read a connection between pins 2 and 4 of a GPIO breakout board?
So, I recently bought this cobbler kit from adafruit, and finished up the soldering as they instructed.
However, after doing so, I hooked the cobbler up to my breadboard to test the connections.
I ...
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2answers
60 views
Can I use this bridge with Raspberry Pi to drive 2 servos and a stepper motor?
I found this SainSmart L293D in amazon. I need to run 2 motors and a stepper motor for my project, the description says it can but I am not clear if they can do all the three at the same time. ...
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2answers
103 views
What can I do on a Pi with an Infrared sensor but no Arduino?
So, in a recent batch of purchases from Adafruit, I picked up one of these $2 gadgets:
http://learn.adafruit.com/ir-sensor/overview
It can pick up signals from TV remotes and such. I'm wondering, ...
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1answer
65 views
Simplest pushbutton input (and LED)
I'm using a Raspberry pi to log GPS tracks in my car, so it's headless and has no network.
What is the simplest way to add a pushbutton to receive an input that will enable me to:
stop the GPS ...
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1answer
57 views
How to get an SPI Analog-to-Digital (MCP3204) working with the GPIO?
I have an MCP3204 12-bit Analog-to-Digital Converter (ADC), and a Raspberrypi. Does anyone know what I need to plug where to get them to communicate?
Is there an SPI python library I can use?
O am ...
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1answer
50 views
Why is my read data MCP23017 not working
I'm trying to add a button to my MCP23017 board. But my code is not working. What am i doing wrong?
import smbus
import sys
import getopt
import time
bus = smbus.SMBus(1)
...
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1answer
80 views
Can I use these two inputs (GPIO) at the same time?
I realize this is a very specific question and its probably due to my lack of understanding of the GPIO pins...though I keep trying to understand. (I just must be dense)
I bought and have working the ...
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1answer
144 views
raspberry pi django and RPi
Did anyone installed RPi and use it in the django Python framework? I've tried to wire up a motion sensor with the django but I'm stuck while trying to use RPi.GPIO inside django view and I get:
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2answers
301 views
Sending Commands from PC to Raspberry Pi via USB
I am currently doing a project with the Raspberry Pi as a controller connected to a PC via USB and using the Pi to send commands to other devices connected via GPIO pins.
Simplified version: ...
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1answer
84 views
Why do one have to be root to acces gpio?
I have long wondered about this.
I mean there are a lot of low level stuff that a user can get access to.
If a driver exports gpio to /dev/gpio and that file is writable by group gpio how would that ...
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1answer
93 views
How can I use the RPi GPIO to make a headphone sensing audio jack?
I am working on a project that involves a raspberry pi acting as an internet radio client which the public can access by plugging their own headphones into a 3.5mm (1/8”) jack. They will have access ...
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2answers
302 views
Raspberry PI and fingerprint scanner
How can I make Raspberry PI work with a fingerprint scanner like this?
I found something for Arduino only (http://learn.adafruit.com/adafruit-optical-fingerprint-sensor) Are there any tutorials for ...
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1answer
115 views
What happens when we connect the 5V GPIO output with the Ground, why does it restart?
I want to know, what happens when we connect the 5V GPIO output with the Ground of the GPIO, and why the RPi restarts. Also if it's possible, I want to know what's the Technical Explanation for this ...
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1answer
24 views
Resetting a server with RasPi's GPIO
I have a server (standard ATX motherboard) that tends to lock up, and I'd like to reset it using the Raspi. I know the motherboard has a reset switch/jumper, but I don't know what voltage it outputs ...
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1answer
57 views
Bash Script with GPIO fails - what am I doing wrong?
This simple bash script always executes with my embedded error message, 'Something went horribly wrong.'
This script was originally coded by someone else; I have no idea what (exactly) gpio -g mode ...
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1answer
123 views
Has anyone manage to drive a HD44780 LCD using a 74HC595 shift register?
Using Python, I am trying to interface with a HD44780 16x2 LCD display and would like to save a few pins from my Pi's GPIO banks by using a 74HC595 shift register.
So far, I have managed to run the ...
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1answer
86 views
Random GPIO values when ribbon cable is connected
I've installed the GPIO python library to read/write to GPIO pins. To get the state of the pins I'm using "gpio readall" which displays a table with all the pins from the RPI and I can see which pin ...
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1answer
54 views
What is the pin distance of GPIO
I'm going to buy necessary stuff for using the GPIO from a Czech reseller to avoid the shipping costs. For this, I need to know: What is the nominal distance of the pins on the GPIO?
(I don't have my ...
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1answer
77 views
Python Synth with Raspberry
I'm trying to create a synth using python with raspberry pi. I've written the code for manipulate the gpio input (i've modified the electronic of an old pianola and connected it to raspberry with the ...
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1answer
135 views
Time a GPIO input
I want to time the duration a input GPIO pin is HIGH with microsecond precision.
I tried while loop with time.time(), but it adds a lot of rogue delays.
Any ideas?
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1answer
263 views
Start/stop Fan at certain time
I have connected a fan to my raspberry pi with a transistor that sits on pin 5 ( GPIO 5 ).'
I followed this "guide" to make it: ...
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1answer
230 views
How to connect single GPIO pins?
I want to connect an IR receiver and a gas meter impluse reader to the GPIO port.
I saw those ribbon cables, but they have much more wires than needed.
Can I by these small connectors for single ...
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1answer
256 views
How to get pin addresses on a MCP23017
Recently I purchased a few MCP23017. I've been reading up on them and I've gotten a few lights to turn on and such. I am having a problem trying to understand how to figure out the register address ...
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1answer
155 views
Closing a circuit with GPIO
I'd like to use the GPIO pins on my RasPi to close a circuit. I don't want any power applied to the circuit either from or to the RasPi, just something as simple as touching two wires together to ...
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1answer
68 views
input from GPIO requires touching composite video
I have a simple input setup via GPIO, on a headless PI (no video cables attached) The input it attached to a simple button. If I create a while loop and print out the status of the input, it goes ...
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1answer
81 views
Locked (Atomic) Register read/write
I'm coding something using direct control of GPIO, there are some good resources around for this, such as http://elinux.org/RPi_Low-level_peripherals#GPIO_hardware_hacking ; the process involves ...
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2answers
205 views
Can I drive a Solid State Relay directly from GPIO?
I was thinking of using my Raspberry Pi to control a switch (control a lamp, for instance). I have a traditional (electromechanical) relay, but I know I will need to use an external transistor and ...
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228 views
Using additional GPIOs as digital I/O?
hopefully this question is rather simple but my quick googling did not find the answer.
I know that the RPi has several GPIOs that I can use as well as specialized GPIOs (SPI, I2C, UART, etc). In my ...
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1answer
169 views
How can I connect an L298 H-bridge motor driver using Pi-Face
I have a Pi-Face which I have successfully used to switch on and off some LED's but I'm a bit stuck on taking the next step - to drive a robot chassis.
I purchased one of these l298 motor drivers but ...
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1answer
94 views
Is there a software block diagram that describes how a python call (e.g. GPIO) gets to the hardware?
Is there a software block diagram that describes how a python call (e.g. GPIO) gets to the hardware? I would assume there is a user/kernel interface. Maybe a kernel module that implements support ...
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2answers
107 views
Electrical characteristics of GPIO
Is there a spec sheet anywhere which lists the electrical specifications for the varios GPIO pins on the RPi revision B? For example, if they are open collector etc, output voltage, max input voltage, ...
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1answer
80 views
Correctly grounding a circuit
I have a very simple circuit using the Adafruit breakout Pi cobbler kit with a HC-SR04 ultrasound module. The circuit works fine (I can trigger and read the echo back) but it doesn't seem to be ...
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3answers
295 views
Raspberry Pi Video Output
Is there any way for me to use my laptop screen as a screen for my Pi (Model B)? The cost of a HDMI to VGA converter as well as a good monitor with HDMI connectivity are a little high.
I have a ...
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1answer
175 views
Connecting Pi to laptop (macbook)
Brief Question:
I am working on a project that requires me to execute a C++ program on my laptop, and, the result of the program will determine the actions of the Raspberry Pi, which is triggered ...
4
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1answer
131 views
AD7705 analog to digital converter with RPi, viable?
I have a couple of AD7705 chips I'm attempting to use with my RPi to read the analog pins from a sensor that spits out 0~4V. Nice, detailed datasheet for the ADC is here:
...
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1answer
133 views
How to use GPIO?
I've bought a Raspberry and I did some easy test, I studied it and I' m very curious about GPIO connection and how to use it. How could I control that? I'd like to start controlling a LED on a bread ...
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2answers
178 views
Relay and GPIO Question
This is a newbie on using the GPIO on the Raspberry Pi. I also did some search and reading about using the GPIO, but I am confused
What I'm going to do is to attach an 8 relay to the RPI.
This is ...
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0answers
154 views
Raspberry Pi on AVC-LAN / IEBus
I'm planning on using my Raspberry Pi in my car as an XBMC server. I'll be able to select songs/videos using the Android remote control app, but it occurred to me that it would be really neat if I ...
13
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1answer
627 views
Circuit to safely power-down Pi
I want to use my Pi as an XBMC server in the car. The XBMC docs say that you should always use the shutdown command before disconnecting the power.
I've been thinking that it should be possible to ...
2
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2answers
702 views
What's the right way to run a python script as a daemon (service) in raspbian (or debian)?
I'd like to use my Pi as a home thermostat, with the control loop running in a python script. I want to run it as a daemon on raspbian (debian) at startup.
There's an example bash script in ...
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1answer
258 views
How do i connect a buzzer to GPIO
I have a PS1240P02BT piezzo-electric buzzer. I want to drive it with a software generated 3.3V 4KHz square wave from one of the GPIOS.
What kind of resistor do I need between the buzzer and the GND ...
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1answer
41 views
Periodic process stalls
Was wondering if anyone is familiar with this - I've got the RPi working as an LED controller, sending digital color data 60 times per second to some WS2801 LED controller chips. Everything's working ...
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2answers
429 views
PIR Sensor with RPi
newbie here.. can some one help me please.
I have a cheap PIR sensor, which I bought from ebay. It has three pins. It uses 9v battery.
i am able to detect motion with it, as i am able to light up a ...
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1answer
69 views
permissions on /dev entries
I'm waiting for my pi. From reading the tutorials and books on doing i/o on the pi I'm getting the impression that linux makes entries in /dev on the fly, which is nice, but they're owned by someone ...
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4answers
1k views
Raspberry pi maximum relays that I can connect
I want to control multiple relays in my house using the raspberry pi.
How manny relays can I control using it ?
