Note

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Touch Screen Example

Introduction

This example demonstrates the touch device point-reading process based on the RT-Smart touch HAL, and includes two modes:

• Read point test using an existing touch device

• Read point test after dynamically creating a device through configuration parameters

Example source code: src/rtsmart/examples/peripheral/touch/test_touch.c

Example Capabilities

• Read and print touch point events (DOWN/MOVE/UP)

• Support multi-touch data reading (example buffer upper limit is 5 points)

• Print device capability information (maximum touch points, coordinate range, etc.)

• Print current touch configuration and default rotation information

• Support Ctrl+C safe exit, and automatically release resources

Key Interfaces (Corresponding to Actual Code)

• drv_touch_inst_create(): Create a touch instance

• drv_touch_read(): Read touch point data

• drv_touch_get_info(): Query device information

• drv_touch_get_config(): Read device configuration

• drv_touch_get_default_rotate(): Read default rotation

• drv_touch_inst_destroy(): Destroy instance

• canmv_misc_create_touch_device(): Dynamically register a touch device

• canmv_misc_delete_touch_device(): Delete dynamically registered device

Compilation and Running

Compilation

Enable the corresponding example in the SDK root directory and then compile, or compile independently:

cd src/rtsmart/examples/peripheral/touch
make

Run Mode 1: Test Existing Device

./test_touch -d 0

Run Mode 2: Test After Dynamically Creating Device

./test_touch -c --index 1 --range-x 480 --range-y 800 --int-pin 23 --int-value 1 --reset-pin 22 --reset-value 0 --i2c-bus 3 --i2c-speed 400000

Note: When the example exits, it will automatically attempt to unregister the touch device created through -c.

Common Parameters

Parameter	Description
-d, --device	Use an existing touch device ID (default 0)
-c, --create	Dynamically create a touch device based on subsequent parameters
--index	New device index
--range-x, --range-y	Coordinate range
--int-pin, --int-value	Interrupt pin and active level
--reset-pin, --reset-value	Reset pin and active level
--i2c-bus, --i2c-speed	I2C bus number and speed

Output Interpretation

The example will print:

• Device basic information: type, vendor, maximum touch points, coordinate range

• Current configuration: I2C, pins, display range, etc.

• Contact details: event, track_id, x/y, width, timestamp

When there are no events, the example will periodically output ., indicating the loop is running normally but currently has no touch data.

Tip

Touch input typically depends on I2C + GPIO (interrupt/reset). It is recommended to confirm pin multiplexing and level configuration first, then perform the touch reading test. For complete interface and call sequence, please refer to the Touch API Documentation.