When building embedded systems, connecting peripherals should be the easy part.
Yet many electronics projects still begin with manually wiring sensors, checking pinouts, searching for compatible libraries, and troubleshooting loose jumper wires before any real development can begin.
The new PTSolns I2Connect Series was created to simplify that entire process.
Built around the industry standard I2C communication protocol, every I2Connect module uses the same compact form factor, the same connectors, the same mounting pattern, and the same philosophy: plug it in, install the library, and start building.
Today we're excited to release the first three members of the family:
These are only the beginning, with many more modules already in development.
One Ecosystem, Many Possibilities
The goal of the I2Connect Series is to make adding peripherals to a microcontroller as simple as possible.
Whether you need environmental sensors, displays, user interfaces, memory, or motion sensing, every module follows the same design principles.
Current and upcoming modules include:
- AHT20: Temperature & Humidity
- VEML7700: Ambient Light & Lux
- EEPROM: 2 Mbit Non Volatile Memory
- Buttons: 4×4 User Input Matrix
- Digit Display: Dual 7 Segment Display
- ICP20100: Pressure & Temperature
- KXTJ3 1057: Three Axis Accelerometer
- MUX: Four Channel I2C Multiplexer
- OLED: 0.96 inch 128 × 64 Display
- I2C Doctor: I2C Bus Diagnostic and Recovery Module
As new modules are introduced, users can continue expanding existing projects without learning new connectors, wiring methods, or software interfaces.
Built Around I2C
Every I2Connect module communicates using I2C, one of the most widely used communication protocols in embedded electronics.
Unlike interfaces that require numerous signal wires, I2C uses only two communication lines:
- SDA (Serial Data)
- SCL (Serial Clock)
Along with power and ground, these four connections allow dozens of peripherals to share the same communication bus.
Each device has its own address, allowing a microcontroller to communicate with individual modules independently. Standard I2C supports communication speeds of 100 kHz, 400 kHz, and up to 1 MHz depending on the connected devices.
Because virtually every modern microcontroller includes native I2C hardware, the I2Connect Series is compatible with an enormous range of development platforms.
Qwiic Compatible
One of the defining features of the I2Connect Series is the use of Qwiic compatible connectors.
Qwiic, originally introduced by SparkFun, standardizes I2C connections using compact four pin JST SH connectors with a 1.0 mm pitch.
Each connector carries:
- Ground
- Supply Voltage
- SDA
- SCL
No soldering is required.
Simply connect one module to another using a standard Qwiic cable and the devices immediately share the same I2C bus.
Every I2Connect module includes two Qwiic compatible connectors, allowing modules to be daisy chained together without requiring hubs or splitters.
Also Compatible with STEMMA QT
Because Adafruit's STEMMA QT system uses the exact same four pin JST SH connector and identical pinout, every I2Connect module is fully compatible with both ecosystems.
That means users can freely mix:
- PTSolns I2Connect modules
- SparkFun Qwiic devices
- Adafruit STEMMA QT peripherals
on the same I2C bus, dramatically expanding the number of compatible devices available for any project.
Designed for Both 3.3 V and 5 V Systems
One common frustration in embedded design is voltage compatibility.
Some sensors only operate at 3.3 V while others expect 5 V logic.
Every I2Connect module has been designed to operate with both 3.3 V and 5 V systems, making them equally at home on Arduino Uno boards, modern ARM development boards, ESP32 platforms, Raspberry Pi Pico boards, and countless other microcontrollers.
This removes another obstacle that often slows down prototyping.
Breadboard Friendly
Although Qwiic cables make wiring extremely simple, we recognize that many developers prototype using solderless breadboards.
Every I2Connect module includes a preinstalled right angle male header that plugs directly into a standard breadboard while keeping the PCB upright for easy access. All the modules come fully assembled, with the angled headers soldered and ready to plug-and-play.
This allows users to choose whichever connection method best fits their project without purchasing additional adapters or soldering headers.
Consistent Mechanical Design
Every module in the I2Connect Series follows the same mechanical philosophy.
Modules share similar PCB dimensions, connector placement, and mounting hole locations, making projects look cleaner while simplifying enclosure design.
As additional modules are released, they integrate naturally alongside existing boards without requiring mechanical redesign.
Software That Gets You Started Quickly
Hardware is only half the story.
Every I2Connect module includes a dedicated open source library developed specifically for the PTSolns ecosystem.
Libraries are available through both:
- PTSolns IDE Library Manager
- Arduino Library Manager
This allows users to install the required software with only a few clicks before immediately running the included examples.
Each library is accompanied by comprehensive documentation, example programs, wiring diagrams, and API references hosted in the PTSolns Documentation Repository.
Installing the libraries is straightforward. Both the PTSolns IDE and the Arduino IDE include integrated Library Managers, allowing users to install the required library directly from within the development environment. Simply open the Library Manager, search for the appropriate I2Connect library (for example, I2Connect_AHT20, I2Connect_VEML7700, or I2Connect_EEPROM), click Install, and the library is immediately ready to use. This eliminates the need to manually download ZIP files or manage library folders, helping users get up and running in just a few minutes.
Meet the First Three Modules
I2Connect: AHT20
The AHT20 measures both temperature and relative humidity using a digital sensor.
Typical applications include:
- Indoor climate monitoring
- Weather stations
- Greenhouses
- HVAC systems
- Data logging
- Smart home automation
The accompanying library provides a simple interface for reading temperature and humidity while handling device initialization and communication automatically.
I2Connect: VEML7700
The VEML7700 is a high resolution ambient light sensor capable of measuring illumination over an exceptionally wide range.
Applications include:
- Automatic display brightness
- Indoor lighting control
- Environmental monitoring
- Smart buildings
- Energy management
The custom library simplifies lux measurements while exposing configuration options such as integration time and gain for users requiring maximum measurement accuracy.
I2Connect: EEPROM
The EEPROM module provides 2 Mbit (256 KB) of non volatile memory that retains information even after power is removed.
Typical uses include:
- Device configuration
- Calibration constants
- User preferences
- Event logging
- Sensor history
- Persistent application data
Internally the memory is divided into four 64 KB address spaces.
Rather than requiring users to manually manage these partitions, the custom I2Connect EEPROM library presents the entire memory as one continuous 256 KB address range while automatically handling page boundaries, address translation, and multi device communication.
More Modules Are On The Way
The first three releases establish the foundation for the I2Connect ecosystem, but they are only the beginning.
Displays, buttons, pressure sensors, motion sensors, multiplexers, diagnostic tools, and additional expansion modules are already under development.
Our goal is simple:
Build a growing ecosystem of high quality plug and play I2C peripherals that work together seamlessly, allowing makers, students, educators, and professionals to spend less time wiring hardware and more time creating.
We look forward to seeing what you build with the I2Connect Series.