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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No clock signal on SCL pin of PIC16F1618

I have been trying to configure I2C on PIC16F1618 microcontroller. I am using MPLAB X IDE, along with xc8 compiler. The MSSP code is being generated through MPLAB code configurator. I have set the ...
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3answers
76 views

GPIO esd protection

I came across NXP app note highlighting esd protection for GPIO pins. I found two different schemes for digital IO and I2C as given below: As far as I know, I2C pins are same as Uni-directional ...
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45 views

Differences & Similarities between I2C & SPI Analyzers [closed]

I am learning about I2C and SPI analyzers and want to know about the differences between the two. What is the difference between their functionality and what are the similarities in these analyzers, ...
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31 views

Daisy changing 5+ I2c sensors with only two available addresses [duplicate]

Im looking to daisy chain 5+ I2c devices with only two available addresses. One default and another that is active once a pin is set to high. Im looking to minimise the amount of cables between each ...
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1answer
46 views

Common ground between a current source and a power supply

I want to design a simple circuitry for testing a bench top current source through a load resistor. I want to use MAX9611, and read data through I2C by a micro-controller. The rough circuit schematic ...
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2answers
94 views

How to calibrate the MLX90616 IR temperature sensor?

I have purchased some Melexis mlx90616 IR temperature sensors. The data sheet states that a calibration “by the customer” is required. By contacting my purchaser I got the answer: "The supplier has ...
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1answer
64 views

why dumy write in I2C Read operation [closed]

I am not getting why there is dummy write in read operation. please help me with explanation. thank you,
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26 views

mma8452 no i2c comms

I'm trying to get an MMA8452 working with a small 8-bit micro (8051 based). I'm bit-banging the I2C interface but the MMA8452 never responds. Looking at the scope, the comms frequency is about 60 kHz ...
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1answer
55 views

I2C to IrDA - any pitfalls?

I need to operate a peripheral chip via bidirectional I2C across a significant air gap (30mm) and powered wirelessly. Has anyone done the I2C to IrDA? Any problems? Any better solutions? I want to ...
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23 views

Nexys4DDR temperature sensor reading code error

I am trying to read the temperature sensor on my Nexys4DDR board using i2c protocol. My code is outputting all of the leds as 1, thus giving me the default value. Where am I going wrong? ...
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4answers
78 views

Can I2C be used with momentary sensors?

[edit: clarifying the question] Is it possible to see events on I2C slaves, or a functional equivalent? I'm brainstorming a new project. I'm using an ESP-12F as a main logic board to control and ...
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1answer
56 views

MPU6050 won't ACK

I'm trying to get my MSP430 to talk to a MPU-6050 sensor via I2C. If anyone can spot-check this hardware and see if there's a problem there, I'd be grateful. The resistors are connected to the red ...
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1answer
77 views

How does I2C work? [closed]

WARNING: I HAVE NEVER DONE I2C BEFORE. Hi. I need to connect 2 I2C devices to a PIC microcontroller with a single I2C port. I saw this answer where two I2C devices were connected to an Arduino. ...
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48 views

Can't get I2C to work with DS3231 and MSP430 due to hanging issues

I am currently using an MSP430G2 processor. I am trying to get I2C communication between it and a DS3231 timer chip to work properly. ...
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0answers
56 views

Convert RTC date and time to Seconds in Pic24f?

I am building an application with PIC24f where it needs to send data to server for every 120s .I have used time interrupt to do this task but internally it gives some problem so i would like to move ...
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1answer
33 views

How do you implement an Energia interrupt handler?

So, I have an application that needs to be very conservative with the power. I use the suspend() command to go into LPM4 and wait for an interrupt to occur. During the interrupt, I attempt to ...
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3answers
174 views

I2C communication won't start unless SDA pullup resistor is reinserted

I'm working on a project where a PIC12LF1552 microprocessor is using I2C to talk to a TMP75 temperature sensor. Like the title says, a very strange issue keeps happening. Overview Every time I ...
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2answers
29 views

I2C ADC IC for many components located separately?

my first question in this page :) The sensors I use give analog signals, so I want to translate them all to I2C, but I can't find IC's that allow me to give them any desired address, I find only with ...
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3answers
78 views

Using CAN bus tranceivers with custom data link layer

We needed a noise immune, low cost, multidrop, multi master (realtime and distributed) protocol and there is only CAN bus seems to meet with these requirements. Since there are no can controllers ...
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1answer
74 views

Can a slave i2c IC prevent the master from pulling the the signal low?

I have an MSP430F6659 connected to a ISO1541 via I2C with 1.5K pull-ups. The I2C bus is through wire instead of PCB trace so I'm able to swap out identical PCBs with the ISO1541 ICs. One of these ...
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1answer
170 views

I2C protocol between PIC32mx and Arduino Uno

I am implementing a way to transfer data using I2C protocol between PIC32mx and Arduino Uno. I've decided to establish PIC as master and Arduino as slave. I passed by all the definitions and configs ...
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2answers
74 views

Using two pressure sensors with same address over I2C

I'm a novice programmer and I have recently purchased the SparkFun Pressure Sensor Breakout - MS5803-14BA and used it to take pressure readings quiet easily with the sample code provided and an ...
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45 views

Why does MSP430G2553 get stuck on Transmit()?

I've been banging my head against the wall for days trying to get my LaunchPad to work with Code Composer Studio doing some very simple I2C. I have tried several examples found on the internet and ...
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1answer
77 views

Design for Multiple I2C slave devices

I'm doing a PCB in which I'm using the Beagle Bone Black to interact with multiple I2C devices. I have attached a schematic. Out of the many I2C devices, I'm connecting some using TI's I2C switch ...
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9 views

How do I use TI_USCI_I2C_slave_present method from TI_USCI_I2C_master

I'm trying to implement I2C to communicate with a device at address 0x53. I'm starting with a simple device scanner that that detects I2C devices on the bus. There is a function called ...
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26 views

switched 5V and 0V on my I/O expander IC (i2c)

I'm almost sure i switched the 5V and GND for a while on my MCP23017-SP (thats how the expander IC is called) I need it for my RPi2, i tested for i2c connection on my RPi2 using ...
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1answer
68 views

i2c undefined symbols on compile MPLab XC8

I am trying to compile a simple I2C program for a PIC18F45K22 using MPLab XC8 compiler. I am getting the error: :0: error: (500) undefined symbols: apparently relating to _WriteI2C1, _ReadI2C1 ...
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1answer
139 views

How can I connect dozens of sensors of the same address to one i2c bus?

I want to connect dozens of i2c sensors of the same type to one arduino. Reprogramming the address is unfortunately not possible for all the sensors. I will illustrate what I mean with the following ...
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2answers
59 views

I2C level shifting to multiple voltages inside a BMS

We're building a BMS that has a micro on each cell in the pack. I know this isn't standard and the issues that come with it, however the pack isn't a standard layout, and the benefits out weigh the ...
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1answer
90 views

Assign I²C address to multiple devices on the same bus

I've got a couple of ADCs on the same I²C bus, which all default to the same address. My first instinct tells me to use an I²C multiplexer like the TCA9544A but that would require sending a byte to ...
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1answer
52 views

Can I requst data too quickly from an I²C ADC?

I'm getting some pretty noisy data from a 12-bit I²C ADC (MAX11617 to be precise). Though it's most likely some very sub-optimal board layout that's introducing a lot of noise to the analog signal, ...
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1answer
52 views

how do you typically tie the address pins and WP pin of I2C device? Do these lines need a pull-up/down resistor or just tied directly [closed]

how do you typically tie the address pins and WP pin of I2C device? Do these lines need a pull-up/down resistor or just tied directly.
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1answer
64 views

Unwrapping measurements from Adxl345 accelerometer

I am trying to read acceleration values from a ADXL345 via I2C. I've successfully configured the accelerometer with a resolution of 16G. Test 1: 180° rotation along the y axis in 16G resolution. The ...
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3answers
89 views

I2C data line not having correct voltage levels

I've been working on a project with a EFM8UB1 development board and ATECC508 I2C peripheral. Everything works fine but I'm having problems with I2C when moving to a PCB. Here is a trace of the clock ...
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55 views

AR1020 correct I2C communication protocol

i have a problem in the right sequence of I2C communication protocol to communicate with the attached device AR1020 Microchip touch controller so does any one have the idea of the correct sequence ...
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2answers
46 views

I2C bus multiplexing issue

I am seeing an unexpected side effect, and could use some pointers. I am working on a project which uses five TCS34725 color sensors. These sensors are being interfaced via I2C on a TI F28069M DSP ...
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94 views

I2C writing is successful, but reading fails

I'm trying to make my Beaglebone Black(rev C, debian 7.9) communicate with OV7670 camera via I2C. Using the i2ctools in the Beaglebone's linux, I could detect the OV7670 camera and see its device ...
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3answers
66 views

Groovy i2C/SPI peripherals for education?

I'm helping someone teach an embedded programming course at my university, and he's starting to cover i2C in class. SPI is next. We're trying to come up with a groovy, easy-to-interface, low-cost ...
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1answer
38 views

I2C Master communication with a Ten bit slave

I have a doubt related to 10-bit mode of I2C protocol for multiple transactions with repeated start: I would like to know how an i2c master / slave has to be designed to support 10 bit addressing for ...
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1answer
65 views

STM32F303VC I2C works in Debug mode only [closed]

I am interfacing HDC1000 with STM32F303VC. My I2C code works in Debugging mode only. Other Blinky and UART code works properly. Write works perfectly but, Read function code stuck here: ...
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1answer
69 views

How to make SirfStar IV chip operate as I2C slave only?

I bought a GPS that has SirfStar GSD4e chipset inside. I see with the logic analyser that when in I2C mode it is writing to the bus. I understand by that that it is in master mode. How can I make it ...
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1answer
67 views

TCA9548A I2C switch register functionality

I'm developing a little program to control the TI DRV2605LEVM-MD evaluation module, similar to the TI Haptics Control Console, but specific for this board. It consists of a MSP430 microcontroller, a ...
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1answer
84 views

Programming MSP430G2553 with Raspberry Pi 2

So, i want to program a msp430g2553 microcontroller with raspberry pi 2. Since i don't want to use any IDE i would like to do it with clean C and terminal, without any external libraries like ...
5
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1answer
93 views

I2C slave not acknowledging consistently

I'm trying to communicate with a Cypress CapSense module, model CY8CMBR3106S. During initial testing, I used Cypress's CY3240-I2USB USB-I2C bridge, which works perfectly. I then moved to an Arduino ...
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1answer
191 views

Software i2C communication protocol “MikroC for Pic” halting problem

I work with Pic16f688 , and i do a soft i2C MikroC for pic compiler does not supply its libraries functions code this is the whole code i use for MCU ...
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2answers
50 views

I2C Voltage levels with difference [duplicate]

I have an I2C slave device in which the maximum input voltage to SCL & SDA is 3.6V. And the I2C Master device is PIC16F877A operating at 20MHz which provides a 5V output on SCL & SDA. Pls ...
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1answer
86 views

STM8S I2C Master Missing ACK

I use I2C communication with two stm8s boards. My master code: ...
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1answer
107 views

stm8s I2C Communication

I want to use I2C Communication between two stm8s208cb MCUs. I use stm8s standard peripharel library. My code: Master: ...
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2answers
231 views

Flickering on PCA9685 PWM controller with 3W RGB LED and Picobuck

I'm hoping someone here has some experience with the PCA 9685 PWM controller (16 channel, I2c interface). So far everything is working pretty well after getting the circuit connected properly. I'm ...
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1answer
138 views

What is that meaning of “This Sensor uses 5v as a working Voltage only”?

I am trying to understand the meaning of a 3.3v or 5v IC but I don't know how to use the right keyword in search engine to find the explaining article so I'll explain... We know Arduino UNO R3 as ...