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

1
vote
0answers
27 views

16x2 LCD displaying blocks when connected with MCP23017

I am using a 16x2 LCD and have it connected with MCP23017 16-bit IO port expander. To display message to the LCD, I am using Adafruit LCD library. The also have a test python code to get it working ...
1
vote
1answer
29 views

Using I2c port as standart GPIO

When I try to use I2c1 SDA pin (GPIO 2 BCM number) via GpioController::OpenPin() func, it compiles OK but it throws an exception HRESULT:0x80070490 Element not found. How should I use I2c pins as any ...
0
votes
1answer
39 views

How do you decide between communication protocols? [on hold]

I'm experimenting with using the raspberry pi as well as an FPGA, and I want to try making some program that runs on the pi but uses the FPGA for processing. When looking at the pi output pins I ...
0
votes
2answers
39 views

Using I2C in C++ on Raspberry Pi

I have a Raspberry Pi model B with Raspbian and a Busware SD0 cape. The SD0 has an RTC that can be read via the I2C bus. I want set the time and date of the Raspberry Pi because it is not always ...
0
votes
1answer
50 views

BCM 2835 library vs WiringPi library

What is the best library of these two? What are deference of these two libraries?
0
votes
1answer
29 views

Firmware modules not available in rasbian os

I am working on a project. I have rasbian installed on my raspberry pi. When i do sud lsmod i have no output. I cannot use lirc and i2c module has this require firmware modules.I have to submit the ...
1
vote
1answer
36 views

Strongly typed language for the Raspberry Pi? [closed]

I would like to know if there is a matrix somewhere that list the languages that could be used on a Raspberry Pi. I've a broad experience in C# and a not to bad knowledge of Java. For my first weeks ...
0
votes
1answer
71 views

LIDAR Lite giving random address

I am using LIDAR Lite module (website) to calculate the distance and it uses I2C connection. I connect the pins out of the LIDAR into a level shifter since RPi accepts 3.3V. When I run the command ...
1
vote
1answer
27 views

How to unbind i2c bus 0 from the i2c driver?

It seems a I2C component (Gyroscope) I am using with my Raspberry Pi B+ makes my Pi Camera hangs after a while. I read I must unbind the i2c bus 0 from the Linux (Raspbian) from the i2c driver. I ...
3
votes
1answer
157 views

i2cdetect shows every possible address

I was trying to turn on I2C following this tutorial http://www.raspberrypi-spy.co.uk/2014/11/enabling-the-i2c-interface-on-the-raspberry-pi/ But I have problem which I cannot solve. The command ...
1
vote
1answer
111 views

rpi2 raspbian i2c error - bmp 180 sensor

i am having a lot of trouble getting the pi2 to recognize the sensor, even after configuring the i2c for pi and following this guide several times.: ...
1
vote
0answers
52 views

I2C and camera issues

Is there any know issue by using I2C components and the Pi Camera at the same time? I am using: Raspberry Pi B+, running Raspbian (updated and upgraded to the lastest versions) MPU6050 3 Axis ...
1
vote
1answer
60 views

I2C device not showing

I have a Raspberry Pi 2 running Raspbian 3.18.11 I connected a DS18B20 sensor via i2c. Problem is: it does not show up on i2cdetect -y 1 However, that data from the sensor is available at ...
0
votes
1answer
30 views

Setting PN532 operating mode

How do you set operating mode of PN532 NFC reader/writer? Tutorial on ITEAD PN532 states which codes should be used to set system into I2C (SET0=1 SET1=0) and SPI (SET0=0 SET1=1) mode (default is ...
0
votes
1answer
130 views

Input/output error while receiving the string from arduino via i2c

Im trying to send string data from arduino to raspberry pi via i2c. Raspberry pi can receive the data of particular length(probably32 bytes) of string since bus.read_i2c_block_data(address,0) read ...
3
votes
1answer
90 views

Has anyone successfully used I2C repeated starts on the PI2? My scope says they are broken

I've looked at all the info that I could find on I2C repeated starts, and I tested a simple example that uses ioctl calls with the standard two message structure required to cause a repeated start: ...
0
votes
0answers
67 views

How to interface raspberry pi and Mbed microcontroller using I2c?

I want to interface raspberrp pi and Mbed microcontroller through I2c bus. Both operate at 3.3v , i have connected Rpi SCL ----> mbed SCL ,RPI SDA------> mbed SDA,RPI gnd -----> mbed gnd. After ...
2
votes
1answer
59 views

Raspberryi pi doesn't show i2c address

I need a level shifter circuit between 5v and 3.3v. I'm interfacing two devices raspberry pi and arduino using I2C protocol. I google about level shifter for raspberry pi and arduino. I got this ...
1
vote
0answers
60 views

Not all devices that are connection via I2C are showing

I have linked this chip to my raspberry pi. I used these instructions to do it then installed everything I was told to install using these ...
1
vote
0answers
37 views

I2C rpi i/o error

I'm trying to send multiple bytes of data to an arduino from the RPi but when using : Def writenumbersecond(values) : bus.write_byte(0x04, values) Return None But when calling this data it ...
1
vote
1answer
186 views

Raspberry Pi 2 Broadcom BCM2708/2709 I2C Driver Source File

I've been modifying the low-level driver for I2C on the Raspberry Pi 2. But after not seeing much effect after recompilation and deploy, I'm wondering if I'm actually editing the correct source file. ...
0
votes
0answers
79 views

i2cdetect -y 1 detects my driver the first time, not the second. Code generates i/o error

After having several issues with this grove i2c motor driver I decided to test the i2cdetect once again to ensure it is connected to my bus. I see that it was on 0x0f like expected and, by mistake, ...
3
votes
1answer
104 views

Raspberry Pi as slave

I am using a Pi compute module and wish to make two of them to communicate to each other. I have hooked up some slave I2C devices to it (RTC, Temperature sensor). So I don't think making Pi as slave ...
1
vote
1answer
132 views

Microstack Accelerometer not working. I2C issue?

I just received a Microstack Accelerometer about a week and a half ago. I put the Accelerometer onto the Microstack Baseboard and followed all of the instructions that were provided here. When I go ...
1
vote
1answer
48 views

Why is I2C disabled by default?

It seems that, to use I2C, we need to: un-blacklist I2C with sudo nano /etc/modprobe.d/raspi-blacklist.conf enable I2C kernel module with sudo nano /etc/modules Why is it disabled + blacklisted by ...
3
votes
1answer
116 views

Can't activate I2C on my B+

I'm trying to use the I2C pins on my Pi. All guides I can find talks about that I have to activate it using ether /etc/modprobe.d/raspi-blacklist.conf or raspi-config. However, nether works, the file ...
1
vote
1answer
89 views

How do I access the Wii Nunchuck using WiringPi

The Wii nunchuck is an I2C accessible device and can be wired to the I2C pins of a Pi. How do I read the data from a Wii nunchuck in C using the WiringPi library?
1
vote
0answers
43 views

Troubleshooting MCP23017 based display

I am having trouble getting characters to display on my Adafruit 16x2 blue/white monochrome LCD + keypad. I am wondering how best to isolate the problem as either hardware or software. It shows up in ...
2
votes
1answer
175 views

BMP180 allow to read calibration but fail to read data

I have BMP180 connected to my pi, i can read calibration data from it, but when i try to get pressure / temperature data -- i get 80 00 for temp and 80 00 00 for pressure (mean -- 'just-after-reboot ...
2
votes
1answer
179 views

What bitrate can I get from an i2c bus?

In short, what is the maximum bitrate that can be achieved writing to an I2C bus from a Raspberry Pi? Should it be the theoretical maximum of 100KB/s? In more detail, I'm writing to an I2C bus from ...
1
vote
1answer
63 views

Smallest possible baudrate for i2c?

I set it to 1200 $ cat /boot/config.txt [...] dtparam=i2c_arm=on,i2c_arm=on_baudrate=1200 but $ cat /sys/module/i2c_bcm2708/parameters/baudrate 3814 Is this the minimum? Can I somehow go below ...
0
votes
0answers
123 views

Problems Bit-Bashing an I2C Slave

I have a Pi B+ on which I'm trying to bit-bash an I2C Slave in C / C++ (code's pretty much C despite the fact I'm using g++ and .cpp files), utilizing GPIO 18 as my Clock and GPIO 17 as my Data. I'm ...
1
vote
2answers
308 views

Locating I2C pull-up resistors for RPi2

I am working with a project where the I2C pull-up resistors need to altered. Unfortunately i cannot find any documentation that can tell me: (a) if there is any pull-up resistors and (b) what size ...
0
votes
2answers
296 views

How can I use a LCD display with a I2C adapter?

I'd like to try to communicate to a 16x2 LCD display, however whole docs I found assume I should connect the whole pin-out however I got some kind of I2C adapter from mjkdz.com which makes a 4 pin ...
2
votes
2answers
139 views

Resetting I2C? Or did I break my chip?

I'm connecting a TS45315 light sensor on an Adafruit breakoutboard to the I2C bus of my Raspberry. I access the data through the following simple Python script: ...
0
votes
2answers
189 views

I2C not working as expected

I'm running a Pi B+ rev 1.2 and recently acquired 2 I2C modules: DS-RGBW.S LED lighting Microstack accelerometer: When connecting the LED module, address 70 appears to be occupied as planned. I ...
2
votes
1answer
292 views

What does raspi-config do when you enable i2c?

Is there any documentation for the raspi-config command that would explain what it actually does when enabling i2c? In the past I have just removed the i2c blacklist, added the modules and made sure ...
1
vote
1answer
185 views

I2C LCD detected, code runs, but no display

I'm trying to drive a 16x2 LCD board with i2c and running into some unexpected results. Basically, I can detect it, talk to it with my code, but nothing shows up on the screen. Same screen when ...
0
votes
0answers
34 views

Changing from spi bus to i2c bus to transfer register data of wm5102 in raspberry pi with wolfson audio card

I'm using wolfson audio card on raspberry pi b+ board.Current wm5102 driver uses spi bus to transfer register data but i want to use i2c bus to transfer data.By reading data sheet of 5102 i understood ...
0
votes
0answers
46 views

Using sensors and dc motors with MCP23017

Can I use a Raspberry Pi Model B along with MCP23017 to take inputs from 5 digital sensors and give output to 6 'normal' 12v DC motors? The Pi is already working as a webserver with a USB camera. I ...
0
votes
0answers
130 views

How to set up MPU6050's registers properly?

I would like to use the MPU6050 as IMU in my quadcopter. I've been Googling for 2 days, but I can't find anything where there are explained well. I know that the settings are not general, but I hope ...
2
votes
1answer
159 views

Accessing ADXL345

I'm trying to access an ADXL345 Accelerometer mounted on a Sparkfun breakoutboard via Python and I2C from a Raspberry B+. I'm following this tutorial However when trying to check for the sensor with ...
0
votes
0answers
202 views

Different “Adafruit 16x2 Character LCD + Keypad for Raspberry Pi” Python Libraries & Sunfounder plate

I have the SunFounder I2C interface 16x2 LCD Pi Plate with KeyPad with RGB LED for Raspberry Pi plate (this model available at Amazon (sorry I have only the german link - the picture is showing the ...
0
votes
2answers
187 views

Rasclock does not store the time

I just received my Rasclock V4, and set it up according to Afterthought's instructions. Seeing as I'm doing this on a RPi B+, with the latest raspbian image downloaded from raspberrypi.org just ...
0
votes
1answer
151 views

Python, C, I2C, calling binary with arguments, and printing output [on hold]

I have a C binary that takes 1 argument. I need to have Python run the binary, and return the output. Using subprocess.Popen (and check_output), the C binary fails when trying to write to the I2C ...
1
vote
1answer
126 views

baudrate config changes only after starting x

I've changed an i2c config file so current baudrate is 300000. I do a reboot and start an i2c baudrate checking program. sudo ./checkbr But what I get seems to be usual baudrate settings(default). ...
0
votes
2answers
101 views

MPU6050 gyroscope not responding

I was testing my MPU6050 with Raspberry PI and got accelerometer(X,Y,Z) and gyroscope(X,Y,Z) data forming on registers at decentely high sample rate. Looks like I've accidently fed +5v from RPI to SDA ...
14
votes
2answers
16k 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
49 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
348 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 ...