CST328 MicroPython Driver

Table of Contents

• Introduction
• Main Features
• Hardware Requirements
• Software Environment
• File Structure
• File Descriptions
• Quick Start
• Notes
• Version History
• Contact
• License

Introduction

CST328 is an I2C capacitive touch controller driver for MicroPython. It supports single-point touch detection and coordinate reporting via I2C interface. The driver uses 16-bit register addressing for touch data access and supports optional interrupt-driven touch detection with ISR-safe internal handler or user-provided callback.

Note: This driver has passed static code review only and has NOT been hardware verified.

Main Features

• Single-point capacitive touch detection
• I2C communication with 16-bit register addressing support
• Optional interrupt pin support with ISR-safe internal handler
• External callback injection for custom interrupt handling
• Optional hardware reset pin support
• Automatic retry mechanism for transient I2C errors
• Debug logging support
• Configurable touch screen logical size
• Pure MicroPython implementation with no third-party dependencies

Hardware Requirements

Recommended test hardware: - Any MicroPython-compatible board with I2C support (ESP32, RP2040, etc.) - CST328 capacitive touch panel module - Logic level converter (if necessary)

Software Environment

File Structure

cst328_driver/
├── code/
│   ├── cst328.py        # Core driver
│   └── main.py           # Test example
├── package.json          # Package configuration
└── README.md             # Documentation

File Descriptions

Quick Start

1. Copy code/cst328.py and code/main.py to your MicroPython device.
2. Connect the CST328 module according to the pin table above.
3. Edit the pin definitions in main.py (SCL_PIN, SDA_PIN, RST_PIN, IRQ_PIN) to match your wiring.
4. Run main.py.

Minimum runnable code example:

from machine import I2C, Pin
from cst328 import CST328

i2c = I2C(0, scl=Pin(22), sda=Pin(21), freq=400000)
rst_pin = Pin(19, Pin.OUT)
irq_pin = Pin(18, Pin.IN)

touch = CST328(i2c, rst_pin=rst_pin, irq_pin=irq_pin, width=320, height=240)

while True:
    point = touch.read_point()
    if point is not None:
        print("Touch: x=%d, y=%d" % (point["x"], point["y"]))

Notes

Version History

Contact

• Email: FreakStudio@example.com
• GitHub: https://github.com/FreakStudioCN

License

MIT License

Copyright (c) 2026 FreakStudio

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.