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Questions tagged [i2c]

I²C stands for Inter-Integrated circuit, and is a data transferation system that allows connections between computers or microcontrollers and low-level peripherals (e.g. sensors or EEPROMS). It is a multi-master, multi-slave, single-ended, serial computer bus.

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5V-3.3V Sensors Confusion

Most of the sensors available in the market requires 3.3V-5V. The GPIO of the Raspberry Pi is 3.3V max only and not 5V tolerant. I have seen tutorials around the internet that they supply the sensors ...
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20 views

Printer Using Raspberry Pi and Arduino

Well I'am creating a printer that works with raspberry pi as processor and Arduino as the microcontroller. The raspberry pi will be connected to a linux/windows system that sends file to pi. Also USB ...
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1answer
31 views

Using RTC on Raspberry Pi Zero while SDA/SCL pins are occupied

I have a portable project on my Raspberry Pi Zero and I am using a i2c 0.96" OLED on the SDA/SCL pins on my Raspberry Pi. I would like to add a RTC Module to my project, but all of the tutorials I ...
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1answer
20 views

I2C slave on a RPi Model B with pigpio?

I want to use the I2C slave provided by pigpio with a Raspberry Model B. pigpio documentation says GPIO 18 and 19 are used for that. Unfortunately there is no GPIO 19 on an RPi1. Is it possible to ...
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33 views

I2C devices not detected on Pi Zero

I'm trying to connect an OLED screen to an RPI zero through I2C. They look a little out of date, but I followed the instructions here (more or less), but i2cdetect -y 1 Doesn't find anything... In ...
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1answer
34 views

{ [Error: , Remote I/O error] errno: 121, code: '', syscall: 'writeByte' } from raspberry pi to Azure

I tried to follow the instruction below to send sensor data from my raspberry pi 2 to Azure. Connect Raspberry Pi to Azure IoT Hub (Node.js) I connected the sensors to my pi device in a different ...
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23 views

Cannot Import board [closed]

I just follow this tutorial https://learn.adafruit.com/adafruit-bmp280-barometric-pressure-plus-temperature-sensor-breakout/circuitpython-test, previously I download board from pip because I tough I ...
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41 views

LCD Display with I2C gives garbage when called by interrupt

I have problems with a 2x16 LCD Display controlled via I2C. I use python 2.7 and have a Raspberry Pi Zero W. When called from the main loop everything works fine and I can access the display with ...
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24 views

Converting C driver to NodeJS

I am looking for a bit of guidance. I am attempting to convert a Arduino LCD driver to nodejs. LCD:https://www.dfrobot.com/product-1737.html - spec PDF after bottom. I have researched I2C protocol, ...
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26 views

i2cdetect detects device - Pi can't access / find it

Currently I'm working with a gyro-sensor and need to use i2c in order to use it. Using a Pi 3 B (os:NOOBS) on kernel: Linux raspberrypi 4.14.98-v7+ #1200 SMP Tue Feb 12 20:27:48 GMT 2019 armv7l GNU/...
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1answer
26 views

Upon starting Node-RED my Pi detects all of its i2c addresses as connected

I've been trying to connect an MPU-9250 module to my raspberry pi B+ in order to output the sensor's data through a Node-RED UI, i followed this tutorial to setup the MP-9250: https://kingtidesailing....
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26 views

Raspberry Pi Current & Voltage Sensors (10A rating and ~40V respectively)

I've been searching through multiple forums, and gone to different links online trying to find a "cheap" solution to my question. I am currently trying to monitor the current and voltage of an ...
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33 views

Si7021 temperature & humidity reader — Python code errors

I'm new at this. I bought an Si7021 temperature and humidity sensor, and it's wired to a breadboard -- I believe correctly. I have code, here, from the book "Make: Jumpstarting the Raspberry Pi Zero ...
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1answer
33 views

enable software i2c on raspberry pi gpio

I am trying to interface more than one sensor with Raspberry Pi Zero W, which communicate using i2c interface. So far I am able to connect sensor to dedicated i2c and read the data. Want to know ...
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26 views

Unable to get accurate RPM with Adafruit Stepper Motor HAT v0.1

I'm trying to drive some stepper motors using a Raspberry Pi 3 B V1.2 and an Adafruit Stepper Motor HAT v0.1 and am having trouble setting them to the speed I want. The motors have a step angle of 1.8 ...
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1answer
33 views

I2C Level Shifter 3,3V Raspi 5V Arduino Mega

I am connecting Raspi (Master) via I2C with Arduino Mega (Slave). Do I need a level shifter for this or is it non compulsory? As of now my code runs for some time before i get a Remote I/O Error ...
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2answers
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How to get the i2c ground signal to pass into the rasberry pi

I want to build a circuit, that is a Raspberry Pi Zero W, powering 8 Adafruit Alphanumeric displays (or even more). The max, theoretical current draw from an Adafruit Alphanumeric is 280mA. ...
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1answer
95 views

I2C Programm stops running after a few seconds / Remote I/O Error nr 121

i have an Arduino Mega hooked as slave to the raspi via i2c. My python scripts looks like this import smbus import time bus = smbus.SMBus(1) SLAVE_ADDRESS = 0x08 def requestreading(): block = ...
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0answers
20 views

I2C Raspi (Master) Arduino Mega (Slave) creating a csv File from sensor values

i am trying to connect raspi 3 (master) with an Arduino Mega (slave). I have 4 analog sensors on the on the Arduino Pins A0 - A3. I now want to be able to manually start and stop the readings from ...
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1answer
29 views

I2C instability

I2C was working great for over a month using an Adafruit Motor Hat, and an LSM303 accelerator/compass also on the interface passing through the Motor Hat and consuming 3v. As a side note, power-wise, ...
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105 views

Can't get MLX90640 working

Warning. Really long post. Hi. I’ve been having problems in getting my MLX90640 thermal camera to work on my Raspberry Pi Zero W. I’ve connected the camera to Pins 1,3,5,7,9 as instructed. I then ...
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How to stop the NXP NFC-EXPLORE library from interfering with my i2c oled display?

I've been working on a new project with my raspberry pi 3b+ to turn in into a NFC jukebox/bluetooth speaker and I used the NXP EXPLORE-NFC header to take on the NFC scanning part. I've connected it ...
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py532lib - i2c - Working But Too Many Files Open After A While

I'm successfully reading data from my NFC tags with the py532lib, using the i2c connection, put out by Hubcitylabs 5 years ago. https://github.com/HubCityLabs/py532lib/blob/master/py532lib/i2c.py ...
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31 views

Pcf8591 Analog to Digital Converter with raspberry pi

I am novice to the raspberry pi. So, i am interested to know that how can i setup pcf9591 with raspberry pi. Because, i want to get analog values from analog sensor. Can anyone suggest the circuit ...
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2answers
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I2C Detect shows that Rasberry Pi keeps assigning the same address to 2 devices

I'm trying to hook up 2 Adafruit Quad Alphanumeric displays to my Rasberry Pi 3 B+. From what I understand, all I need to do is hookup the displays in series to the SDA SCL outs, and the I2C chip is ...
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1answer
36 views

reading bmc280 & tsl2561

I am trying to read bme280 & tsl2561 on Pi Zero. I have connected bme280 to Pi Zero on Pin 3-I2C.1 SDA & Pin 5-I2C.1 SCL and was able to read the data over i2c following these instruction. ...
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37 views

I2C pin states when RPi powered off

I have a setup where RPi may join existing I2C -bus as master when powered on. Before taking over, it will first notify secondary master with "slave select" -line so that the bus becomes free for ...
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31 views

using I2C in threads

I have several devices on one I2C Bus and am wondering now what happens, if I have some threads using this one I2C Bus. Do I need to implement a scheduler or is the I2C Bus automatically blocked ...
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1answer
71 views

Connect 6 accelerometers to Raspberry Pi

I need to connect 6 LIS3DH Accelerometers to a Raspberry Pi. Is this possible, and how would I do this? Do I need to use I2C or SPI? Or do I need something like an I2C multiplexer? (If another type ...
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extra i2c bus and circuitpython lib(Raspberry Pi)

I'm a newbie to Ras Pi and I am having trouble with i2c sensors. I bought SHT31d from Adafruit Industries to measure Temp and Humidity in several spots in my house. I used to use DHT22 before, but ...
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1answer
80 views

I2C bus 0 not working, I2C bus 1 is

I am using both the i2c-0 and i2c-1 busses on my raspberry pi compute module 3. I can use i2c-1 no problem. Full comms, can probe the line and see good signals, get good signals back and the good old ...
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1answer
58 views

How to connect 6 LCD 16x2 to a Raspberry Pi 3?

I need help with this project. I want to connect SIX LCD 16x2 screens to my Pi and send different messages between the screens. I was wondering if I could use I2C but there is a problem with the ...
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43 views

CPU peaks at regular intervals on w1_bus_master1

I've recently changed my hardware from RPI2 (boot from flash card, Raspbian 8 Jessie) to RPI3 (boot from usb->ssd, Raspbian 9 Stretch), cabling and sensors are the same. On the new RPI when I do "top"...
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1answer
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How do I add an i2c device to the device tree?

I am trying to add an mpu 9250 to the device tree of my RPi 3 A+ so that my custom driver's probe function will be called. I have followed this documentation about the Raspberry Pi device tree and ...
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1answer
62 views

How to access to I2C software with wiringpi library-

I want to use I2C software instead hardware I2C. Because a buggy parto of the I2C related with clock stretching. I can enable in boot.txt adding this: dtoverlay=i2c-gpio,bus=3 It would create a /...
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How to create a communication between Raspberry pi 3 and Photon (Wi-Fi IoT platform)?

I have search hundreds of website, I watched many videos, but I cannot understand how to make raspberry pi talk to Photon, where it could read a sensors or turn led on or off, etc...) I managed to ...
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1answer
336 views

OSError: [Errno 121] Remote I/O error or pigpio.error: 'I2C read failed' on MPU6050

So I use MPU6050 to get acceleration from stepper motor linear rail movement(steper motor working in thread, I use pigpio for the motor) by make the MPU6050 can work on threading and it can show data ...
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3answers
141 views

i2cdetect doesn't catch ANY address (no device detection)

I have ti046b1 chip (Serial I2C F-RAM) to read. I tried to read it with my raspberry Pi 3, so I connected SDA SCL VDD GND as shown in pictures, but when I run the command "i2cdetect -y 1" on my ...
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1answer
82 views

Trouble accessing Sensirion sht21 though multiplexer tca9548a using i2c and python

I can't reach my sht21 sensor throughout the Multiplexer tca9548a (adafruit). When I run it with python3 in the raspberry pi's terminal, I get this error report: Traceback (most recent call last): ...
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2answers
164 views

RPi to Arduino I2C block_data read fails with “Errno 121, Remote I/O error” (Python3)

Folks, I cringe to bring this up as it has been discussed frequently, but I am at a loss. Background: I have a Raspberry project with about 3000 lines of Python3 code and want to add a wireless ...
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1answer
78 views

I2C device (DS3231 RTC) not detected

I have a small DS3231 RTC module, like the following, that I am trying to get to work with my PI 3 Model B. However it is not correctly being detected by the Pi. Connected like so (ignore cables, ...
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2answers
103 views

Protect raspberry i2c pins with general ground connection with Arduino

I have connection like on the screen I have 12 arduinos. Each of them has one general 12V power supply. The problem is when i connect one of the Arduino supply (while all scheme works) Raspberry pi ...
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1answer
72 views

Is SPI in Raspberry Pi Reliable..?

I'am trying to initiate a two way communication between Raspberry pi and Arduino. I worked with spidev library and directly using the SPDR register in the Arduino micro-controller without being able ...
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1answer
60 views

I don't know whether I have fried the I2C port on the Raspberry Pi 3 B

I am using a Raspberry Pi to send data to an Arduino Nano using I2C and it was working fine by just connecting the SDA, SCL and GND pins together from the Pi and the arduino. I then tried to get ...
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1answer
131 views

Raspberry Pi not detecting MPU6050 with i2cdetect

I am trying to connect my GY-521 MPU6050 to my Raspberry Pi Zero W using I2C detect but I'm unable to find the MPU6050 on the table. The results using i2cdetect: pi@raspberrypi:~ $ sudo i2cdetect -...
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1answer
104 views

RPi I2C Master vs. slave with Arduino

I have an Moteino board (similar to Arduino with a radio module). The Moteino uses the radio module to collect weather data from my Davis weather station. I want to use I2C to send this data to an ...
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0answers
160 views

Multiple Devices with I2C

I'm attempting to read data from the VL53L1X-SATEL and the TSL2561 Luminosity Sensor at the same time using I2C on the Raspberry Pi 3 B+. When just the vl53l1x is connected I get the following from ...
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1answer
84 views

Really strange but with RTIMULib2, why does it not work in a class?

I'm doing a project with an accelerometer/gyrometer combo and I'm using the great RTIMULib2 library. I know installing it and getting it to even work at all is a common challenge, but I've gotten it ...
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1answer
100 views

Wiring Omron D6T Thermal Sensor to Raspberry Pi Zero W with Adafruit T-Cobbler Plus

I have a Raspberry Pi Zero W connected to a Adafruit T-Cobbler Plus and breadboard. My question is regarding wiring. I have followed tutorials to create simple circuits, however, I am struggling to ...
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1answer
126 views

How can I get /dev/i2c-* devices to appear on Alpine Linux?

I have loaded the appropriate kernel modules and set them to load upon boot (i2c-dev and i2c_bcm2835). A call to lsmod confirms that they do indeed load on boot. But alas, I don't see any i2c devices ...