Inter-process Communication with Qt (Part 4)

This is the next part of the Inter-process Communication with Qt series, where we bridge the gap between software and hardware using Qt's communication modules. Since most machines lack a physical serial port — and a spare microcontroller — Matt Aber shows you how to virtualize both: an ESP32 running under QEMU, and a virtual null-modem serial link to your host. He then builds a small QML app, backed by QSerialPort, that sends commands to a simulated motor and displays its live voltage and velocity.

Learn how to:

• Set up and run a virtual ESP32 microcontroller using QEMU and ESP-IDF.
• Emulate a physical serial connection between two machines using the tty0tty null-modem driver.
• Read and write UART data on the microcontroller side using FreeRTOS and the ESP-IDF UART driver.
• Use QSerialPort to open, configure, and communicate over a serial connection in a Qt/QML application.
• Expose serial port data to QML through read-only bound properties and Q\_INVOKABLE functions.
• Enumerate available serial ports at runtime using QSerialPortInfo.

Chapters

00:00 Intro

01:02 Setting Up & Running a Virtual ESP32

03:23 Reading & Writing UART Data on the ESP32

06:28 Emulating a Real Serial Port with tty0tty

11:25 Building the QML Application

12:43 QSerialPort Backend: Setup & Configuration

15:49 Reading, Writing & Parsing Serial Data in Qt

19:29 Updating the Microcontroller & Final Demo

21:29 Outro

Links

• Find the code for this video here...
• All inter-process communication videos
• tty0tty (virtual null-modem driver used in this video)