Hi everyone,
I wanted to share the results of some testing I recently carried out with the new Arduino UNO Q.
Background
I am currently developing a wearable project that requires using an MPU6050 over software I²C so that I can place the bus on arbitrary GPIO pins instead of the hardware I²C pins.
While looking for a suitable library, I first tried SoftwareWire. Unfortunately it did not compile on the UNO Q because it relies on AVR-specific register implementations such as digitalPinToPort() and portModeRegister(), which are not available on the UNO Q's Zephyr-based Arduino core.
After some searching, I came across Andy4495's SWI2C library:
One thing I immediately liked was that the implementation is platform independent and uses only the standard Arduino API (pinMode(), digitalWrite(), and digitalRead()), so I decided to test it on the UNO Q.
Test Environment
Board
- Arduino UNO Q
Microcontroller
- STM32U585 (Arm Cortex-M33)
Arduino Core
- Arduino Zephyr Core v0.56.0
Operating System
- Ubuntu 24.04 LTS
Peripheral
- MPU6050
Software I²C Pins
- SDA → D2
- SCL → D3
Test Procedure
The following functionality was tested:
- Library compiled without modification.
- Software I²C initialized successfully.
- MPU6050 was initialized successfully.
- Continuous 14-byte reads starting from register
0x3B. - Accelerometer data.
- Gyroscope data.
- Temperature data.
- Continuous real-time streaming while moving the sensor.
Results
Everything worked successfully.
The library required no modifications to compile on the UNO Q.
I was able to continuously stream accelerometer, gyroscope and temperature data using arbitrary GPIO pins through software I²C.
The communication remained stable throughout testing.
Screenshots
Serial Output
Upload / Build Environment
Why I'm posting this
The UNO Q is still a relatively new board and there isn't much information available regarding software I²C compatibility.
Hopefully this saves someone else some debugging time if they're trying to use software I²C on the UNO Q.
I have also opened a compatibility report on the SWI2C GitHub repository so the maintainer is aware that the library has now been successfully tested on this platform.
If anyone has tried other software I²C libraries on the UNO Q, I'd be interested to hear your experience as well.