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

learn more… | top users | synonyms

3
votes
1answer
242 views

Firmware 3.18.x breaks I2C, SPI, audio, lirc, 1-wire (e.g. /dev/i2c-1, No such file or directory)

I am using i2c to control a Bright Pi module. I followed instructions from 'Configuring GPIO - Adafruit' and 'Configuring I2C - Adafruit' to set up the I2C. I have done this a few months ago and ...
1
vote
0answers
28 views

I2C PIC18F2520 and PI

I am having a big problem to communicate a PI with PIC using I2C. When I try to use another PIC as master everything works fine, no problem. But swtich to PI I cant get it to work. To start my both ...
1
vote
0answers
44 views

Why I cannot read the temperature/humidity sensor sht20?

I use a temperature and humidity sensor sht20. According to this link: http://www.sensirion.com/en/products/humidity-temperature/humidity-temperature-sensor-sht2x/ It is compatible with sht21, which ...
0
votes
0answers
50 views

Why my Raspberry Pi cannot find Si7021 (temperature and humidity sensor)?

I use this temperature and humidity sensor: Si7021, like below link http://www.dfrobot.com/wiki/index.php/SI7021_Temperature_and_humidity_sensor_SKU:TOY0054 I can get the sensor data by Arduino ...
1
vote
1answer
35 views

Check for I2C device presence

I'm using I2Ctools to read data off of some devices attached to a raspberry pi via the I2C interface. I want to check if a device in a certain address is present or not. If present, read the data from ...
0
votes
1answer
18 views

Sending data to a 1602 LCD in Mono C# over i2c

How would I be able to put information on a 1602 lcd over SPI? I was thinking that it may be possible to write to the pin (like a file) with all the hex codes of the letters etc. or similar. I'm a ...
2
votes
2answers
71 views

i2cdetect strange output

I'm following this tuto http://skpang.co.uk/blog/archives/575 in order to setup my rpi with an I/O port expander. My problem is whenever I run i2cdetect to find out the device, I get a weird output. ...
4
votes
1answer
106 views

Controlling a official lego servo motor via Raspberry Pi

I am able to control a simple servo motor such as SG90 by using pulse-width modulation. However when it comes to controlling a 88004 LEGO Servo Motor it is simply a nightmare. By using PWM all I ...
3
votes
1answer
50 views

Troubleshoot MCP23017 and LEDs

Anyone have any tips to help troubleshoot turning a simple LED on connected through the MCP23017? I've installed i2c-tools, and smbus. Nothing in my blacklist.conf Added i2c-dev to /etc/modules. ...
1
vote
0answers
49 views

Connecting Adafruit NFC breakout and serial console at the same time [closed]

I am electronics newbie but have some programming background. My current hobby project is to make a "thing" which does things based on which NFC badge is waved at it. The tutorial [1] I am following ...
3
votes
1answer
45 views

I2C device inside case + GPIO ribbon outside case

I have a model B in a nice prefab case with a slot through it to connect a 26-wire ribbon to the GPIO header. However, I'd like to leave a small I2C based device inside the case as well. I've ...
1
vote
1answer
33 views

Issues with multiple SDA sensors

I am facing some issues trying to connect two sensors which make use of the SDA GPIO. Ultra sound sensor HC-SR04 Gyroscope & Accelerometer MPU-6050 Separately, they work just fine, however ...
2
votes
1answer
40 views

Sensor minimum/maximum operating voltage

I've bought this sensor, and I'd like to connect it to Raspberry Pi (unless I manage i2c on dagu minidriver). The spec on the sensor say: Minimum operating voltage: 2.5 V Maximum operating ...
0
votes
1answer
58 views

Pins I2C cannot be used as input

When using pin 3 and 5 as inputs, I get only 3.3v and I'm not able to use them as inputs. I use the same code and circuit on all the GPIO pins the circuit worked on every single pin except on this 2 ...
0
votes
0answers
23 views

How to do a repeated start with the Raspberry Pi to get the MMA8452Q accelerometer working?

I am trying to use an MMA8452Q accelerometer with the Raspberry pi B+. I have it hooked up to 5 GPIO pins on the Pi, J8 pins 1/3/5/7/9. After installing some i2c libraries, the Pi recognizes the ...
1
vote
0answers
166 views

I2C problem reading data - only sometimes

I'm using this device, that acts as an I2C slave device on the address 0x23, for communicating with an arduino from a RPi model B. This is an nrf24l01 attached to an AT48 that provides an I2C ...
0
votes
1answer
74 views

Filtering noise w/ pi as FM transmitter and sound source

I have an I2C FM transmitter for the pi; it has a 3.5mm stereo jack for input. Everything works great -- I attached a short dipole antennae and get clear reception for at least 25'. However, if I ...
0
votes
0answers
88 views

Daisy Chaining MCP23017 & Addressing

I'm looking to daisy chain multiple MCP23017 chips (upward of 10) to essentially give me more IO to play with from my Pi. I've started to work on the circuit diagram, but I'm really lost with all ...
0
votes
2answers
66 views

I2C receive handler, as seen on I2C for Arduino

When managing smbus/I2C devices using python with the RPi, is there a way to register a handler function so it is called when a byte is available for read, like in Arduino Wire.onReceive()? Otherwise, ...
0
votes
1answer
48 views

Check whether an I2C slave device is ready or not

I'm using an I2C device connected to an RPi. The device only handles receiving one byte (which is then transferred via radio to a similar device on the other end, that acknowledges the reception of ...
1
vote
0answers
20 views

i2c connection to mopi not working on one image

I'm trying to setup a mopi on my model B running raspbian. At the moment I can't talk to the mopi unit using the mopi and mopicli utilities and i2cdetect shows the following... $ i2cdetect -y 1 ...
0
votes
0answers
45 views

PWM to control brightness on i2c LED backpack?

I have something similar to this, it works, but it's too bright! I am aware that LED brightness can be controlled by pulse width modulation, but I don't know if I can safely do that with an LED ...
1
vote
1answer
107 views

Basic hand (touchless) gesture detection, solution needed

I need a good solution for basic gesture recognition (touchless), like swipe left, up, down, right, "tap" hardware/software for Raspberry Pi. I've seen http://www.hoverlabs.co/#hover which looks very ...
0
votes
2answers
138 views

Use interrupts in i2C between Ardiono and Raspberry Pi

I'm really new to Raspberry Pi and Arduino programming (+ I2C). Recently I start working on a project where I have to connect an Arduino and a Raspberry Pi to send and receive data from each other. ...
0
votes
1answer
62 views

I2C and ST 24C64 (5V Problem)

I`m planning to use the 24C64 EEPROM with my Rasberry Pi. According to the datasheet the EEPROM "Single Supply Voltage" is 4.5 to 5.5 V. (Datasheet: ...
0
votes
1answer
115 views

Sending i2c commands from arduino to pi

The RPi and arduino are connected by I2C and the arduino sends coordinates to the RPi through the wire library. However, the RPi only receives and prints out 0 when it should print out the coordinate. ...
2
votes
1answer
251 views

Model B+ i2c issues with 7 segment display

I purchased a 4 digit 7 segment display from adafruit and got it working on my old model A running adafruit occidentalis operating system. I recently bought a model B+ and installed the latest version ...
0
votes
0answers
22 views

Which power measuring device can transfer the absolute value to a Raspberry PI?

Which power measuring device can transfer the absolute value to a Raspberry PI? Most power measuring device provide an LED which flashes 1000 times per kWh, but do not send the complete value. Are ...
0
votes
0answers
64 views

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 ...
0
votes
0answers
111 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 ...
1
vote
2answers
889 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.
1
vote
1answer
108 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 ...
0
votes
2answers
358 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 ...
1
vote
0answers
106 views

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 ...
1
vote
1answer
166 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 ...
0
votes
0answers
37 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 ...
0
votes
1answer
94 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 ...
0
votes
1answer
188 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 ...
0
votes
1answer
154 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 ...
0
votes
1answer
126 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 ...
0
votes
1answer
341 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 ...
-2
votes
1answer
136 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, ...
0
votes
1answer
260 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 ...
0
votes
1answer
148 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 ...
0
votes
0answers
149 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 ...
0
votes
2answers
499 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. ...
0
votes
1answer
534 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 ...
0
votes
1answer
117 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 ...
0
votes
0answers
96 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 ...
2
votes
2answers
157 views

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 ...