I²C (Inter-Integrated Circuit) is a multi-drop serial bus invented by Philips (now NXP) for communication between ICs on the same PCB, i.e. short distance.

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What is that mean “This Sensor use 5v as a working Voltage only”?

I am trying to understand the mean of 3.3v or 5v IC but I don't know how to use the right keyword in search engine to fine the explain article so I'll explain... We know Arduino UNO R3 as example ...
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2answers
398 views

MCP3424, how to read channels in parallel?

About this question I do not have an electronics engineering background, and this is one of my first challenges with communicating via I2C, and with writing to a register, so please do not assume too ...
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78 views

Is it possible to use two communication protocols in one microcontroller?

So I've been trying to communicate between the Beaglebone Black and atmega through I2C for quite such time and have been facing quite a lot of problems with it. On the other hand I can successfully ...
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19 views

stm8s208cb(slave) and stm105c6t6(master) I2C Communication

I want to use I2C communication between stm8s208cb(slave) and stm8s105c6t6(master). I use stm8s standard peripheral library. stm8s105c6t6(master) code: -in the void main ...
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48 views

Arduino and STM8 I2C Communication

I want to I2C communication stm8s(slave) and arduino uno(master), but it does not work. Arduino Uno(master) code: ...
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24 views

MCP3221 ADC always returns zero in Proteus

I am interfacing PIC18F2320 with MCP3221 ADC over I2C. When I try to read the converted value from ADC, only zeros are returned. I'm using MPLAB libraries. ADC is in A5 address mode. The AIN voltage ...
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64 views

I2C with 1.8V levels without level shifters?

I have problems detecting an MPU-6050 I2C device on the Intel Edison Mini breakout board (it only supports 1.8V levels). According to the thread here, it might be possible to get the sensor working ...
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3answers
57 views

Why can't masters talk to each other in a I2C bus?

I came across an I2C article which lead me to a question. Specifically this part is creating some confusion: "Also, unlike SPI, I2C can support a multi-master system, allowing more than one master to ...
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62 views

Options for video development

What are my options for video development? I am talking buying a development board, then translate that to custom pcbs and hardware. With the rise of smart phones we have seen a plethora of hardware ...
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1answer
36 views

TCA9548A I2C Multiplexer - 10k resistors on the address lines

I'm looking over the schematics and PCB layout of the Adafruit TCA9548A I2C Multiplexer breakout board. I've attached the schematic below. I cannot figure out why there are 10k resistors on the ...
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30 views

I2C communication and configuration issue in STM8L Discover kit

I have a sample code for I2C communication for 2 STM8L Discover devices. One acts as a master and other acts as a slave. This code i developed on top of the already developed example which was ...
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451 views

What small IC could give switchable I2C pullups?

My goal is to replace a DPST on pullup resistors with something simple, cheap and very small that can be activated with the I2C bus voltage. I thought that this might be a common enough requirement ...
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38 views

wireless I2C/SPI communication over XBEE with multiple slaves

Designing a device for vibration condition monitoring, using multiple wireless accelerometers. Intending to have an arduino as the main controller and peripheral accelerometers sending the vibration ...
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65 views

Peripheral Board Power Issue

after having designed some custom PCBs, a main one with an ARM MCU and other peripheral boards.But there is one issue when peripheral boards are plugged into the main one. Please, let me introduce ...
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2answers
115 views

I2C slave not acknowledging

So the setup I am using is a K22FN512 (Arm Cortex M4) along with a AGM01(9DOF sensor board, gyro/accel/mag). The board containing the sensors has an I2C interface to communicate with the two chips ...
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1answer
46 views

Read a 6DOF IMU (Gyro + Accelerometer) using PRU - Beaglebone black

I plan to use an I2C interface in order to read the IMU (SparkFun 6 Degrees of Freedom IMU Digital Combo Board - ITG3200/ADXL345). Since the communication rate using I2C is 400kHz, I thought I should ...
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24 views

FXOS8700CQ Magnetometer Not Outputting Values

I'm currently getting to grips with the FRDM-K64f board and am attempting to access the onboard FXOS8700CQ chip to calculate orientation information. I've managed to get the accelerometer information ...
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34 views

MCP23017 with Raspberry Pi sometimes reset

I use MCP23017 with my Raspberry Pi and sometimes MCP23017 resets. MCP23017 is powered from Raspberry 5V and reset pin is also connected to 5V. MCP23017 is connected to 2 x 8-channel relays. Relays ...
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1answer
40 views

Is NXP's PCA9548A compatible with TI's TCA9548A?

I am using TI's TCA9548A in my Projects, but I would like to know if I can substitute it with PCA9548A from NXP. By comparing the datasheets this seems to be indeed the case, but I am wondering why ...
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30 views

Atmel SAM D10 i2c slave unknown error

I have stumbled across a problem when trying to get a SAM D10 to communicate with a nordic nrf51422 with the nrf as an i2c master, D10 as slave. The nrf has proven working i2c code, even if it is bit ...
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1answer
29 views

Trouble initiating I2C communication with MSP430g2553

I am having difficulty getting I2C communication going on the MSP430g2553. After working on this for a couple of days I finally stripped down the code to what I thought should be the bare bones needed ...
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1answer
32 views

CJMCU-75 — seting the I2C adress

I just got embedded system CJMCU-75 which has LM75A I2C temperature sensor on top of it. I dig into the LM75A documentation and found out that it's I2C address consists of four fixed MSB and three LSB ...
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59 views

I2C - switch scl line

I have two identical I2C devices that I need to use with a single MCU (arduino nano). I have read here on EE that an I2C multiplexer can be used to switch between multiple I2C buses. But I find them ...
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3answers
77 views

Issue with performing I2C read operation from ds1307 to pic18F

As advised by my fellow stackers in my previous post, I tested the "Write_to_slave" function in Proteus as well in real time, by sending bytes to the RTC and the slave is responding appropriately with ...
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69 views

RTC_DS1307 + PIC18F458 displaying time and date as zeroes

I am trying to get the RTCDS1307 + PIC hardware to work in order to display the appropriate data and time. But the problem is that, its displaying the time and date as 00:00:00 and 00/00/2000 as ...
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3answers
105 views

Digital vs Analog signal for data transfer across boards

I have 1 board that reads data from a sensor, while another board wants to get data from that sensor. Is it better to have an ADC on the first board, then send that data via i2c to the 2nd board? Or ...
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1answer
64 views

i2c communication with pic 18f452

I am new to pic coding. I am trying to turn motor according to change of accelerometer in x direction. I am using Pic18f452 and adxl345. But I couldnt figure it out how to communicate with adxl345 ...
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2answers
57 views

Nested I2C multiplexers

I want to provide 12 actuators from a microcontroller (Particle Core) over I2C. The problem is that the drivers for the actuators have all the same I2C addresses. So I'am considering to use I2C ...
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82 views

Can I2C work without pull up resistor?

I'm working with nrf51 board, I'm using I2C to communicate with an accelerometer (see the scheme), the communications are successful but I dont see any pull up resistors in the lines ...
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1answer
101 views

Beagle Bone Black - Error when finding update packages: sudo apt-get update [closed]

I am very new to using any micro controller and I wanted to use an MPU-9250 sensor with the Beagle Bone to give me serial data either through I2C or SPI. Whenever I type ...
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233 views

I2C not working on my first PCB design

I built a simple sensor board connecting a RFDUINO to two I2C components. A ADXL345 accelerometer and a MPR121 Touch controller. The board also includes an RGB LED, vibration motor and Li-Po ...
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63 views

SPI consumes more power than I2C?

Does anyone know if SPI typically draws more current than I2C? The reason I'm asking is that I'm playing with the LIS3DH accelerometer and driving it with an Arduino. When I2C is used, the current ...
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60 views

Programmatically determine what is on the i2c line

I'm working on a project that uses a simple microcontroller (I2C) master, and a component (I2C slave). When the microcontroller receives power the first thing it has to do is determine which device is ...
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2answers
83 views

I2C communication with DAC

I am trying to use a DAC8571 (datasheet) and I'm trying to set up a communication between this convertor and an Arduino Mega via I2C. The communication between the Arduino and my computer is done ...
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1answer
104 views

Unable to read data from I2C?

I am interfacing DS1307 with PIC32MX795F512L using peripheral library. I am able to send data but not able to receive it. ...
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1answer
67 views

Port I2C code from Arduino to Sercom

I'm having a MPU-6050 (gyro / accelerometer), it's connected to Arduino over I2C (via Wiring.h) and everything works well. Now I'm trying to port this code to an Atmel SAMD20 (Cortex M0+), which is ...
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5answers
158 views

I2C bit banging

I have to implement I2C using bit banging as the controller doesnot supports the I2C drivers. So in order to generate SCL clock, there should be delays so as to generate the Clock high and low ...
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57 views

Why there are AC timing characteristics but not DC in I2C interfaced chip?

I'm quite newbie in electronics, and I'd like to learn why there are AC timing characteristics to this particular EEPROM (24LC512) that I'm using but none for DC? Does AC timing constraints apply to ...
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1answer
126 views

SPI and pull-up resistors

I have a breakout that comes with two 10kOhm resistors: one on the SDA and one on SCL. The chip takes a max of 3.6V. AFAIK, I2C needs pull-ups on its pins, but could SPI be used on this module? I'm ...
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1answer
67 views

Unexpected reversed voltage over shunt resistor

I'm trying to measure the current consumption of an accelerometer using a 1kOhm shunt at Vdd. I've read that there's a ~30kOhm resistor at SA0, so grounding it causes a much higher current draw. When ...
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2answers
76 views

How is the electrical bus capacitance for I2C trace calculated?

i am trying to learn how to calculate the bus capacitance of an I2C tree with a master and multiple slaves. For example, in this document from TI, it shows how to calculate the value of the pull up ...
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1answer
155 views

PIC32MX Harmony i2c Driver

I have a bit of a problem figuring out how harmony i2c driver works. Trying to establish connection between PIC32 and a barometric sensor MS5637 have been a bit of a nightmare for me. From sensor's ...
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2answers
105 views

Why are the pins RC3 (SCL) and RC4 (SDA) configured as inputs during I2C initialization in PIC18F?

I am on the process of interfacing a RTC DS1307 with PIC18F. So, the controller will be the master and I2C the slave, therefore the controller will generate clock and data as outputs, If i am right?. ...
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1answer
131 views

Pull-up resistors required on both side of level shifter?

My I2C sensor and my embedded processor do not agree on the logic level. So I need a level shifter. Normally I would put a pair of pull-up resistors on the SDA/SCL lines. With the level shifter in the ...
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2answers
329 views

How to overcome clock stretching on I2C

I have the clock stretching issue on my I2C line, attached is the below snapshot of it.. I have Kinetis K64 board communicating to MAX7304 port expander at 400Khz. Should I get the driver have the ...
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1answer
93 views

I2C EEPROM only first attemt to read correct

I have very strange problem in my circuit. Namely, I have 24LC01 EEPROM connected to my PIC32. I made "library" for reading from and writing to the memory. What is happening is that only first reading ...
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2answers
50 views

Multiple baud rate slaves to a single I2C Master

Can we connect multiple slaves with different baud rates to a master. For example, I am having a temperate sensor which would work at 50kbps and port expander at 400 kbps, Can these two slaves connect ...
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39 views

Adding resistor in parallel to digipot

I'm trying to control a device using a digital potentiometer (AD5245S). In my application I can't tie the low-ref of the potentiometer and ground, so I'm using an I2C optical isolator (ISO1541) to ...
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1answer
42 views

I2C between atmega and Beaglebone Black

I am working for a small project which involves me to communicate between an Atmega and Beaglebone black through I2C. My question is that Atmega has an 8 bit microprocessor and beaglebone black has a ...
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1answer
70 views

i2c multiple master collision

This is a short question but a seemingly important one. Is it possible for a multi-master i2c bus to have two masters send the start byte at almost exactly the same time? If so, what would happen?