I²C stands for Inter-Integrated circuit, and is a data transferation system that allows connections between computers and low-level peripherals.

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Is it possible to use GPIO's simultaneously?

I'm interested in using raspberry to control a number of brushless motors. PWM should be executed parallely to work in needed rate. As far as I've heard, RPi provides only consequent requests to ...
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28 views

Why is my RTC DS1307 not being recognized?

I'm trying to wire up a DS1307 RTC to my Model B Pi. I'm following the diagram as shown in this crude image and I've also tried it like this but it isn't recognized by the Pi. When I run i2cdetect ...
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101 views

Connecting two cameras into a PI

Is it possible? One connects to the CSI port and the other one to the GPIO ports and use the i2c interface to extract the data.
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1answer
61 views

Quadrocopter Motor Movement

A friend and I are trying to build a raspberry pi-powered quadrocopter. We've ordered four ESCs, four motors, and the Pi, but we're having trouble getting a motor to actually move. The motor makes a ...
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2answers
113 views

raspbian wheezy: Package 'i2c-tools' has no installation candidate

I just tried sudo apt-get install i2c-tools and got the following output: Reading package lists... Done Building dependency tree Reading state information... Done Package i2c-tools is not ...
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Should I remove fake-hwclock because my i2c RTC isn't always plugged in?

I have a i2c RTC (rtc-pcf8563) that runs great, but I don't always have it plugged in; is there a way to test to see if the RTC is plugged in and, if not, start fake-hwclock or will I have to dpkg ...
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1answer
63 views

Choosing an OLED / LCD Dispaly

I'm building a simple device where my Raspberry Pi talks to Google Calendar, and displays information about where I'm at on my office door. My code is all in Python It was simple until I started ...
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20 views

Checking if i2C connection has dropped

Have a RPi connected to an arduino via i2C. Every once in a while I lose my i2c bus connection.Does anyone know of a way to automatically checked for a dropped bus via software? I might configure ...
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33 views

Kernel module doesn't call probe function

I'm writing a kernel modul which should work on i2c. The problem is: the probe function doesn't load automatically. AFAIK, it should be called with a correct device driver name. Please correct me if ...
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1answer
63 views

i2cdetect-ed address shifting with each detect

I'm trying to use use an Adafruits 0.56" 7-Segment Backpack (with Holtek HT16K33 chip). My RasPi Rev2 is running Raspbmc. What's causing me problems is that the address of the chip (single one on the ...
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1answer
55 views

display LED Blink Count on I2C 16x2 LCD

I want to blink a LED and display its count on I2C 16x2 LCD. But LED is not glowing at all. I used https://www.adafruit.com/product/1115 which uses i2c . I connected LED with 270ohm resister between ...
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1answer
71 views

I2C LCD w/ buttons - C

I'm have a 16x2 LCD button shield for RPI similar to Adafruits. It works using the provided Python library so the setup is ok. The problem is I can't find any working C code or library to work with ...
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1answer
157 views

ImportError: No module named Adafruit_I2C

This looks like a common problem but it makes no sense to me I made a test program with "import Adafruit_I2C" as the only line and I get the Import error. I have run sudo apt-get update sudo ...
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1answer
86 views

Whats the most ideal way of communication between an Arduino and a Raspberry Pi?

I am kinda new to a raspberry Pi (just brought mine before writing this post) but i am looking to see what is the most ideal way for two way communication between an Arduino and a Raspberry Pi (USB, ...
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1answer
137 views

Pi4J i2c error: Error writing to /dev/i2c-1 at address 0x21. Got -20001

I'm trying to use the Pi4J java library to write data to an IO Expander via i2C. When I create a new instance of the MCP23017GpioProvider class using the following code: mcp = new ...
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1answer
73 views

i2c device doesn't work on different arch linux install

I have two Raspberry Pi's both model B revision 2, both running the most recent version of Arch Linux from NOOBS. I have tried my best to replicate the install procedure to get i2c working on both ...
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93 views

Making Raspberry pi talk to MyRio

I have a project where I need to use a NI MyRIO from NationalInstruments and a Raspberry Pi. I need to be able to send some data from some sensors on the RPi to MyRio and from MyRio to the RPi. The ...
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1answer
250 views

Raspberry pi GPIO extension

I recently started using rasperry pi. I am trying to do some home automation and controlling TOY car motors. I am able to control the motors and 2 plug points. I wanted to control more servo motors. I ...
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211 views

Tried the standard fixes - still getting FATAL: Module i2c-bcm2708 not found

I've removed the offending lines in (namely all lines)- /etc/modprobe.d/raspi-blacklist.conf I've adjusted /etc/modules to read: snd-bcm2835 i2c-dev i2c-bcm2708 When I try: modprobe i2c-dev I ...
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1answer
67 views

I2C stops working if a DiBcom DVB USB adapter is plugged

I can't help to get my I2C device (an Adafruit Pi Plate I just bought and built) to work in my Raspbian machine. Although the command sudo modprobe i2c-bcm2708 showed no errors, something strange ...
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60 views

is there a library for raspberry pi to use with MMA8452 I2C Three Axis Accelerometer Module?

I bought this accelerometer : http://www.fasttech.com/products/0/10000007/1012002-mma8452-i2c-three-axis-accelerometer-module I would like to use it with raspberry pi, I know that it is possible ...
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2answers
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I2C with zener protection isn't working

I wanted to put some protection on my PI's pins and chose the zener voltage protection one, as described here. I used TZX3V3A zener diodes and 330 ohms resistors. Like this : Then i tried to ...
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3answers
549 views

How to use 2 x MCP23017?

I need to control 32 L.E.D's individually, now looking through the forum, the common solution is to use MCP23017 chips, as they can control 16 l.e.d's. With that in mind, I would require two chips. ...
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166 views

How to connect more than 1 am2315 temp rh sensor to respberrypi

Hi I have to read temp and rh from 2 locations. so I bought 2 am2315 sensors which is i2c logiced temp rh sensor. I connected it as shown in the below diagram, and its working fine. I can read data ...
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216 views

Disable i2c in Raspberry Pi

I want to disable the i2c in raspberry pi, so that I can use it as GPIOs. I commented the lines in the /etc/modprobe.d/raspi-blacklist.conf, but not working.
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1k views

Controlling Multiple analog RGB 12V led strips

I need to control several (5 to 10) analog RGB strips which have a separate power supply at 12V or 24V. Just like this one for example. I need to control the intensity of each colour channel for each ...
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1answer
89 views

Connecting Raspberry Pis With I2C

I would like to connect 6 slave RPis to 1 master RPi via I2C. Has this been done before and is it even possible. I know the I2C interface on the RPi has 1.8K pullup resistors so having all of those ...
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3answers
12k views

Safest way to connect Raspberry Pi to Arduino Uno R3

I am working on a robot using an Arduino Uno R3 and I wanted to have the ability of controlling the Arduino wirelessly, like stopping the Arduino without having to pull the power-plug every time. I ...
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1answer
308 views

Control a SainSmart 20x4 LCD?

I've got some SainSmart 20x4 LCD left over from my Arduino projects and I wanted to check if and how it's possible to get them running with an Raspberry Pi. I've come across this question. ...
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3answers
1k views

I2C devices not detected

I'm running raspbian on my pi and followed this tutorial to get the i2c going. i2cdetect -y 1 used to detect my i2c devices but doesn't anymore. The sensor is connected like this: Could this be a ...
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660 views

i2c data understanding [closed]

let me first say that I'm somewhat of a noob when it comes to i2c and serial communication. I've been trying for 2 days now to grasp it, reading datasheets, youtube videos etc. And I'm having a hard ...
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3answers
2k views

How can I automatically update the hwclock with NTP when I have internet connection

I'm using an RPi with Raspbian which runs the NTP-daemon by default. I have connected an rtc-ds1307 external i2c hardware clock. I was following the instructions given here to set it up: ...
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3answers
1k views

Analog input to the PI

I have a bit of a specialized question for you. Recently I got my Pi up and running, and am amazed at what it can pull off. But I want more. I want to be able to record the output from an ...
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1answer
557 views

Raspberry Pi/“Arduino” communication

I'm looking to use a raspberry pi to speak to multiple "arduino" ATMEGA328p ICs (through a logic-level converter). I figure I can do this reasonably well over the GPIO RX/TX and use qualifiers to let ...
2
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1answer
726 views

How to install smbus to virtualenv?

How to setup python-smbus in the virtual env? Pip does not find any appropriate package. Is there a way to make main python installation's libraries visible to virtual env?
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3answers
1k views

Raspberry Pi and BMP085 (I²C)

I tried to get the temperature and pressure with the BMP085 sensor and my Raspberry Pi (256MB) via I2C. I used this Adafruit tutorial: Using the BMP085 with Raspberry Pi, but this isn't working for ...
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1answer
276 views

HD44780 Character LCD C++ Library

I'm looking for a way to connect my Raspberry Pi Model B to my HD44780 LCD, I've tried the Rpi-hw C++ Library but to no avail. You can find the issue about it here. I've been looking ever since for a ...
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1answer
1k views

Meaning of cmd param in write_i2c_block_data

I am testing i2c communication between Pi and Arduino. The doc says: write_i2c_block_data(addr,cmd,vals) Block Write transaction. int addr,char cmd,long[] None I have this test: On Pi: ...
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465 views

I2C (via BCM2835 library) and a mysterious error

The main function I'm having a problem with is where I'm writing a value to external EEPROM. I clear the EEPROM, then write my value to it, waiting 100ms afterwards. #define BAUD_RATE (int)100e3 // ...
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2answers
534 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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1answer
1k views

What does UU mean for RasClock

I acquired a RasClock made by After Thought Software (http://afterthoughtsoftware.com/products/rasclock) . This is a real time clock using i2c. I wanted to play with its other features via i2c but ...
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2answers
2k views

i2cdetect doesn't catch ANY address. How can I tell if I2C working correctly?

I'm having difficulties interfacing the Raspberry Pi to basically any I2C sensor. I've gone through a lot of tutorials on how to get the I2C driver to work and my connections are correct. Still, ...
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2answers
2k views

Controlling 400 LEDs from a raspberry pi

I have a client who has several large bronze signboards, each with 100-150 little light bulbs on it, totaling approximately 400 bulbs. The bulbs are turned on and off on a schedule, currently by hand ...
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1answer
4k views

I2C cable length and type

I have made some tests with a temperature sensor tmp102 connected with 1m long cables and it works great. Now I am wondering if I can use a 10m long cable and if yes, what type of cable shall I use? ...
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2k views

Using the wiringPi I2C Library

I am trying to figure out how this library works (https://projects.drogon.net/raspberry-pi/wiringpi/i2c-library/) . Firstly, what is int fd that all the functions require. It is never stated. I can't ...
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1answer
1k 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
2k views

MMA8452 I2C module

I am working on Raspberry Pi Model B. I am trying to interface this device over the I2C Bus on the Rpi. My hardware Connections are: RPi Accelerometer Vcc P1_1 ...
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1answer
225 views

Detect version 1 or version 2 Pi

I'm writing a small application that could run on version one Pi ( mine ) or a version two ( co-workers ) that uses the I2C bus. Since the I2C bus is different depending on the version, I was ...
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1answer
446 views

Converting two's complement hex values to binary using PHP

I'm reading x-axis accelerometer data from an IC via the I2C bus using I2C-Tools' ( specifically i2cget ) in Linux. Here is the code that is reading these values: $OUT_X_L_A = shell_exec( 'i2cget -y ...
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285 views

How can I read and write data to a Character Device File in Linux with PHP?

I'm trying to read and write to modules on the I2C bus on a Raspberry Pi using PHP. I'm using fopen() and fskeek(). Below is the code I've been trying to use to read data coming in from the physical ...