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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OLED display using dspic33f i2c

I am trying to use OLED display in dspic33f microchip. I've successfully initialised and sent data using i2c to OLED. I managed to display a small font(8pt) on the OLED. However, when i tried a bigger ...
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32 views

I2C in stm32, Read data from a gauge

I'm having a problem with reading data from a maximGauge via I2C stm32f4. I used the oscilloscope to check the variations of SDA and SCL. Here the results. As u can see, I have the start signal, the ...
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1answer
69 views

Is it possible to daisy chain more than one device using I2C, without hard-wiring the addresses? [on hold]

I wonder is it possible to use daisy-chaining (I2C or any other communication protocol), and instead of assigning each slave an address manually, they should be somehow be intelligent enough to ...
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1answer
42 views

I2C Multiple Masters

I am working on Ti's EK-TM4C1294XL which is basically a Arm Cortex M4 evaluation board. I was going through I2C bus of the same and have the following question regarding the I2C bus. I understand I2C ...
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1answer
43 views

Parallel differential signals

I need to send some I2C data through RJ45 cable between Arduinos. One ATMEGA2560 as master and 1-4 328P's as slaves. I've seen some different configurations and I think for my application the solution ...
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1answer
45 views

Advantages and disadvantages of reading a current-sense amplifier with different gains on I2C

I am writing an I2C wrapper for the MAX9611 chip. For the current-sense amplifier (CSA), according to the datasheet there are 3 selectable gains (1x, 4x and 8x): When I read the 12bit ADC registers ...
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21 views

PIC18F2550 and DS1307 i2c RTC MPLAB assembly code. Have to loop for seconds,mins,hrs

PIC18F2550 and DS1307 i2c RTC MPLAB assembly code. I am using a PIC18f2550 to get time,date,etc from DS1307. I am able to get the seconds,minutes, hours, etc by repeatly CALLing GET_TIME with ...
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19 views

Wiring I2C OLED SSD1306 display to a RedBear BLE nano [on hold]

Does anyone know how to wire an AdaFruit OLED display (https://www.adafruit.com/product/661) to an BLE nano? I cant find any documentation on that. Regards
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1answer
61 views

I²C interface between 3V/5V sensor and a 2.4V MCU

simulate this circuit – Schematic created using CircuitLab I have an ultra low power application where the minimum VDD of my temperature sensor (ADT7420) is 2.7V, while I need to run my MCU at ...
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2answers
69 views

Would it be worthwhile to support UART for a serial 'plug-n-play' interface? Or would it be a waste of time? [closed]

I'm currently working on a project where I'm designing a central circuit board that will feature mini plugin circuitboards. The communication between the main circuit board and the plugin ...
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35 views

Questions regarding using an HDMI cable to transmit SPI, I2C, and UART serial data?

I'm currently working on a design in which I need to transmit serial data over 3 different serial channels. I won't be transmitting data far (1" - 1') but I didn't want to use plain wires. Instead, I ...
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2answers
60 views

Sensor on I2C bus

We are using the Sensor. The sensor communicates with the MCU via I2C. Now, I2C specifications provision the max bus capacitance of 400pF. So, this dictates the no of slaves on my I2C bus. The loading ...
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1answer
76 views

I2C SCL ground issue

I'm working on interfacing 2 development boards. I have control over the 1st development board. The 2nd development board is from a third party vendor. My board (board 1) has a pull up of 3.9K and the ...
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0answers
27 views

I2C arbitration lost error STM32 F3 Discovery

I'm trying to get the data from the LSM303DLHC accelerometer installed on STM32 F3 Discovery board. Right after sending START condition ARLO (Arbitration Lost) flag in ISR register is set. I have ...
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2answers
39 views

Register description PCF8574

I have problem with PCF8754 component. The PCF8754 is connected to stm32 MCU and PINS A2, A1, A0 are connected to GND. It means, that 7bit address is 0x20. I want read pin state(P0 to P7), and write ...
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0answers
30 views

Trigger and Sawtooth Generator for Galvo Mirrors

I am currently searching for a way to control two galvo mirrors (voltage range of -10V to +10V) and triggering a camera to record images. For the two galvos I need to generate two different sawtooth ...
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1answer
46 views

I2C PCA9600 logic side offset + ringing

I am using an NXP PCA9600 I2C bus buffer to drive a 2 meter cable in a two wire configuration. My clock is 100KHz. The bus voltage is 5V and the device sides are 3.3V. I have 350 ohm pull-ups on the ...
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1answer
135 views

STM32F3 I2C communication with Arduino

I am trying to implement the Inter-Integrated Circuit (I2C) of STM32F3 Discovery Board to communicate with 2 slaves (arduino) in my project. However, I cannot send any data to arduino. Here is my ...
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1answer
167 views

Managing I2C address conflicts with multiple MCP23017 on the same bus

I'm using a Raspberry Pi with the I2C master and I successfully wired 8 different MCP23017 chips, each with their respective addresses by setting the last 3 bits of their 7 bit addresses. They are all ...
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68 views

Arduino Interface with I2C Flow Sensor

I have a Honeywell HAFUHT0050L4AXT I2C Flow Sensor that I want to read using an Arduino. Looking at the datasheet, I know that the I2C address is 0x49, and I have had a play with bits of code I've ...
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18 views

How can I find a relative yaw value from an IMU (MPU-6050) based on which direction is currently up?

I'm having a hard time putting this question into words but basically I have an IMU (MPU-6050) and am able to get the data to stream using the i2cDev library. The IMU is in a box and I want to be ...
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1answer
107 views

Addressing registers with I2C STM32F0 HAL libraries

I'm very new to using STM's CUBE and HAL_libraries. I'm using an STM32F0 microcontroler with 32 pins. The schematic for I2C is correct. SO I need a little help here. I have a capacitive sensor (...
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2answers
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TWI/I2C Protocol with HMC5883L Magnetometer with ATMEGA256RFR2 XPLAINED PRO (megaavr)

Im trying to read Data Output Registers of X,Y,Z So far I've been able to: ...
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43 views

Is my I2C address setup correct?

Here is the code: ...
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1answer
23 views

Demux I2C with a relay system or similar

I'm working on a electronic prototype. I have got one I2C communication master and I have six slaves to talk to. But here is the problem: the components are not built to have many addresses: only two ...
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1answer
59 views

I2C interfacing between two chips

I am trying to interface a microcontroller (MSP430) with another chip through I2C. Both datasheets (MSP430 and the other chip) advice me to pull the I2C signals up to VCC. Do I need to pull SDA & ...
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1answer
24 views

I2C Implementation on PIC error

I am referencing this project: http://www.8051projects.net/wiki/I2C_Implementation_on_PIC I am using PIC16F1847 and XC8 as opposed to PIC16F877 and HiTech C so I've had to make a few changes to the ...
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2answers
137 views

Dynamic I²C address

I'm having a problem with a system I'm designing that should support multiple modules, these modules communicate over the I²C bus and all have their own micro-controller which takes care of their own ...
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4answers
873 views

Open drain concept in I2C bus?

(I am mainly from a software background and just started to work on an embedded platform. Excuse me if this is a naive question...) I am planning to write a driver for an EEPROM which is connected to ...
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2answers
154 views

Why do datasheets document protocols from the ground up?

I'm reading a datasheets for a component with I2C interfaces. I can recall the same for datasheets of other components in the past. In these datasheets they include a full description of the I2C ...
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1answer
106 views

STM32F4 HAL I2C only sends address

I am working on a project where I need to set a simple LCD. This LCD use the 'ST7032i' chip to control the LCD. I want to control the LCD over an I²C interface. As controller I use a STM32F4 ...
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1answer
89 views

I2C ideal pull-up resistor calculation

As part of a test i was given the following question: My attempt gave an incorrect answer. The "correct" answer is 1000 ohm but i am having trouble figuring out why. My interpretation; min value ...
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5answers
263 views

Why don't on board communications like I2C, SPI, etc. have error checking in general?

Some error checking methods like parity check, checksum, CRC, etc. are used for wired/wireless communications. However, most of the ICs with interfaces like I2C, SPI, etc. don't use an error checking ...
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1answer
57 views

How do I2C modules select between more than 2 slave addresses?

I am using the TMP112 I2C temperature sensor and noticed that you can choose between 4 slave addresses by connecting the A0 pin to V+, GND, SCL, or SDA. How does the sensor tell between SCL, SDA, and ...
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51 views

PIC32MX350F256 Errata , IO open Drain Issue

In one of our Product we used Microchip micro controller “ PIC32MX350F256L”. Attached image is small part of circuit showing uC interfacing with a SPI device. We are using bit banging communication ...
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1answer
64 views

Write to reserved registers in I2C

I'm trying to get a MPU-9150 motion sensor running with my FPGA-Board. The problem is that my I2C-master library doesn't support writing single bits. According to the Register Map there a for example ...
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2answers
86 views

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
122 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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1answer
47 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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1answer
57 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
144 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
70 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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1answer
65 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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0answers
33 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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92 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
67 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
90 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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69 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. ...
0
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1answer
51 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 ...
4
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3answers
222 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 ...