Note

This is the documentation for the latest development branch and may refer to features that are not available in released versions. If you are looking for the documentation for a specific release, use the drop-down menu on the left and select the desired version.

TOUCH Module API Manual

Overview

The touch module is based on RTT’s touch framework, supporting single-point and multi-point capacitive touch screens as well as resistive touch screens.

API Introduction

The TOUCH class is located under the machine module.

Example

from machine import TOUCH

# Instantiate TOUCH device 0 (system default touch)
tp = TOUCH(0)
# Get TOUCH data (returns a tuple, each element is a TOUCH_INFO object)
p = tp.read()
print(p)
# Print touch point coordinates
# print(p[0].x)
# print(p[0].y)
# print(p[0].event)

Constructor

# System default touch
touch = TOUCH(dev)

# Custom touch device (dev != 0, requires specifying i2c, resolution, etc.)
touch = TOUCH(dev, i2c=my_i2c, range_x=800, range_y=480, rotate=TOUCH.ROTATE_0)

Parameters

• dev: Touch device number, 0 is the system default, non-zero is a custom device.

• rotate: Coordinate rotation, see Constants, default -1 (use device default).

• range_x, range_y: Only valid for custom devices, specifies touch screen resolution.

• i2c: Only valid for custom devices, I2C bus object, required.

• rst, int: Only valid for custom devices, reset/interrupt pin objects, optional.

• Other parameters (such as type, slave_addr) are deprecated.

read Method

TOUCH.read([count])

Get touch data.

Parameters

• count: Maximum number of touch points to read, range [1, maximum supported number], default 1.

Return Value

Returns touch point data, type is tuple (<TOUCH_INFO object>, ...), each element is a TOUCH_INFO instance.

deinit Method

TOUCH.deinit()

Release TOUCH resources.

Parameters

None

Return Value

None

TOUCH_INFO Class

The TOUCH_INFO class is used to store information about touch points. Users can access it through the relevant read-only properties:

• event: Event code, see Constants

• track_id: Touch point ID, used for multi-touch.

• width: Touch point width.

• x: The x coordinate of the touch point.

• y: The y coordinate of the touch point.

• timestamp: Touch point timestamp.

Constants

Touch Events

• TOUCH.EVENT_NONE: No event

• TOUCH.EVENT_UP: Lift up

• TOUCH.EVENT_DOWN: Press down

• TOUCH.EVENT_MOVE: Move

Coordinate Rotation

• TOUCH.ROTATE_0: No rotation

• TOUCH.ROTATE_90: Rotate 90 degrees

• TOUCH.ROTATE_180: Rotate 180 degrees

• TOUCH.ROTATE_270: Rotate 270 degrees

• TOUCH.ROTATE_SWAP_XY: Swap XY

Touch Types (Kept for compatibility, actual values are all 0)

• TOUCH.TYPE_CST226SE

• TOUCH.TYPE_CST328

• TOUCH.TYPE_GT911