App note from NXP Semiconductors shows I2C-bus galvanic isolation solution by splitting the bi-directional bus to unidirectional logic signals and passing them through opto-isolator couplers. Link here (PDF) Many systems that can benefit from the advantages of I2C-bus control are not allowed to share any common reference signal (ground) potential. To prevent any chance of […]
Tag Archives: I2C
App note: Optical isolator for I2C Bus System
App note from Vishay on galvanically isolating I2C bus by optocoupler. Link here (PDF) The I2C bus, also known as inter-IC bus, is a bidirectional, two-wire, multi-user bus. It was developed by Philips Semiconductors to connect microcontrollers, EEPROMs, A/D and D/A converters, I/O interfaces, and other peripherals. For optical isolation between master and slave, an […]
I2C master mode emulator
Dilshan has published a new build: The I2C master mode emulator allows communication with I2C devices by sending or receiving data to/from the I2C bus. To issue the I2C commands, the emulator should connect to a PC over the USB port. After initializing the emulator, the PC and directly control the I2C slave chip/module. This […]
Serial Star, a 4 in 1 USB serial and I2C converter
Jesus Echavarria published a new build: Here’s one of the last board I design the last year. On 2016, I develop the Dual USB Serial and I2C Converter board. Although this board works fine, it has a couple of lacks. First one, is that to use the both converters, you need two free USB ports. […]
MusiCubes project
Michael Teeuw published a new build: Now that the MusiCubes tray is assembled and the RFID-sensor and LEDs are working as expected, It’s time to add the last feature of the original concept: invisible capacitive touch sensors to control the volume of the music. See the full post on Xonay Labs blog. Be sure to […]
App note: Extending I2C communication distance with the DS28E17
App note from Maxim integrated about alternative method to extend I2C bus. Link here (PDF) Systems are increasingly requiring greater distances for I2C buses. This article explains how the DS28E17 can be used to extend the distance of I2C devices while decreasing cost.
Multisensor LoRa device
Mare published a new build: The described device is nearly matchbox-sized board (50 x 24 mm) packed with sensors. Auxilary board is 10x50mm with additional sensors. The module is developed around the Murata ABZ LoRa module, which integrates STM32L072 and samtech SX1276 in tiny 12.5 x 11.6 x 1.76 mm package. More details at Mare & […]
Reading a VGA monitor’s configuration data with I2C and a PocketBeagle
Ken Shirriff wrote an article showing how to read the monitor’s config data using the I2C protocol and a board with an I2C port: Have you ever wondered how your computer knows all the characteristics of your monitor— the supported resolutions, the model, and even the serial number? Most monitors use a system called DDC to communicate […]
How to configure I2C sensors with Arduino
Edward Mallon writes: I’ve spent the last year in the ‘uncanny valley’ of the Arduino. That’s the point where you understand the tutorials at Arduino.cc, but still don’t get much from the material on gitHub because trained programmers would never stoop to using the wire.h library when they could just roll their own in native […]
Logging I2C Data with Bus Pirate and Python
Scott Harden writes, “I’m working on a project which requires I measure temperature via a computer, and I accomplished this with minimal complexity using a Bus Pirate and LM75A I2C temperature sensor.” More details at SWHarden.com. Get your own handy Bus Pirate for $30, including world-wide shipping. Also available from our friendly distributors.
App note: Implementing an I2C reset
Interesting app note from Analog Devices when an I2C communication is broken under some circumstances. Link here (PDF) The I2C bus is a high integrity, robust serial bus used for control purposes in many systems. The primary components that make up a system are at least one master and one slave. Under normal conditions, everything […]
Experimenting with MAX6955
Florin wrote an article about experimenting with MAX6955: My experimenting actually started with MAX6954. After many failed tries due to SPI issues (Maxim uses a special interpretation of the protocol, I read), I switched to MAX6955. MAX6955 is the I2C sibling of MAX6954 (which uses SPI). They both have identical LED driving abilities, only the […]
An AVR Atmega library for multiple HD44780 based LCD connected through i2c
Davide Gironi has posted an I2C multiple HD44780 AVR Atmega library: This library implements a driver for HD44780 lcd connected through PCF8574 port expander. Data is transmitted using only 2 wire over i2c with the PCF8574. This library can drive up to 8 LCD concurrently. Lcd driver is based upon Peter Fleury’s lcd driver HD44780 […]
I2C Continuum
Peter Scargill writes: Success with I2c – once I realised there was something up at the Arduino end which I could work around, my ESP8266 I2c endeavours have been coming on in leaps and bounds! And here is my test rig – or one of them – I have one for I2c display and another […]
App note: USB to I2C bridging with Microchip USB 2.0 Hubs
App note on Microchip’s USB 2.0 Hubs on its I2C support. PDF link here The USB to I2C bridging feature of Microchip’s USB 2.0 hubs provides system designers expanded system control and potential BOM reduction. When using this feature in a system design, a separate USB to I2C device is no longer required and a […]
Bus Pirate support in Python3 for I2C scripting
Steve aka hwstar writes, “I just wanted to let you know that I modified the python Buspirate Bitbang.py file and the I2C.py file to support Python 3.4 for a project I’m working on, and wanted to share these files with the community as they are open source. I uploaded the modified files to Github. These files […]
Getting started with an I2C LCD using a Bus Pirate
Inderpreet over at Embedded Code writes: I got one of these (The LCD!) LCDs from the budget and the motive is to use them to display air quality. Low and behold I got them and these things are tiny… I mean more than I thought. BUT they should get the job done. This post is […]
App note: Microchip dedicated slave devices in I2C systems
An app note on Microchip dedicated slave devices in I2C systems (PDF!): Microchip supplies dedicated slave devices that include a two-wire serial interface that is System Management Bus (SMBus) and I2C™ compatible. The SMBus specification is based on the I2C serial communications protocol, but with some differences. This document describes the key differences that may affect […]
App note: How to design in and program the PCA9641 I2C arbiter
I2C arbiter chip application(PDF) from NXP. The PCA9641 is highly integrated and smart design for 2-1 I2C-bus multiplexer. It is used in a system that needs two masters sharing the same slave devices. The internal switch is programmed by the masters but it will not switch in a middle of the task once owned by […]
I2C injection with the Bus Pirate
David Um writes: I decided to create a simple lab involving an Arduino Uno, in this case a SparkFun RedBoard, and a BlinkM LED that can be controlled over I2C. The Arduino would have a simple sketch that will update the color of the BlinkM and using a Bus Pirate I would then sniff traffic […]