2.16 TOUCH Module API Manual

1. Overview

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

2. API Introduction

The TOUCH class is located under the machine module.

Example

from machine import TOUCH

# Instantiate TOUCH device 0
tp = TOUCH(0)
# Get TOUCH data
p = tp.read()
print(p)
# Print touch point coordinates
# print(p[0].x)
# print(p[0].y)
# print(p[0].event)

Constructor

# when index is 0
touch = TOUCH(index, type = TOUCH.TYPE_CST328, rotate = -1)

# when index is 1
touch = TOUCH(index, type = TOUCH.TYPE_CST328, rotate = -1, range_x = -1, range_y = -1, i2c : I2C = None, slave_addr = None, rst : Pin = None, int : Pin = None)

Parameters

• index: TOUCH device number. When 0, it indicates the use of the system’s built-in touch. When 1, it indicates the use of the CanMV-specific touch driver.

• type: The touch driver type, refer to Touch Types for specific definitions.

• rotate: The rotation of the panel output coordinates relative to the screen coordinates, range [0-3]. Refer to Coordinate Rotation for specific definitions.

• range_x: Valid when index=1. The maximum width of the touch output coordinates.

• range_y: Valid when index=1. The maximum height of the touch output coordinates.

• i2c: Valid when index=1. The I2C bus object used for touch.

• slave_addr: Valid when index=1. The touch device i2c slave address, if not set, use driver default.

• rst: Valid when index=1. The reset pin object for the touch device.

• int: Valid when index=1. The interrupt pin object for the touch device, currently not supported.

read Method

TOUCH.read([count])

Get touch data.

Parameters

• count: Maximum number of touch points to read, range [0:10], default is 0, which means to read all touch points.

Return Value

Returns touch point data, type is a tuple ([tp[, tp...]]), where each tp is an instance of the touch_info class.

deinit Method

TOUCH.deinit()

Release TOUCH resources.

Parameters

None

Return Value

None

3. TOUCH_INFO Class

The TOUCH_INFO class is used to store information about touch points, which users can access through related read-only properties.

• event: Event code, see Touch Events for details.

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

• width: Touch point width.

• x: x-coordinate of the touch point.

• y: y-coordinate of the touch point.

• timestamp: Touch point timestamp.

4. Constants

4.1 Touch Events

• EVENT_NONE: No event.

• EVENT_UP: Touch released after pressing.

• EVENT_DOWN: Touch started when pressed.

• EVENT_MOVE: Touch moved after pressing.

4.2 Coordinate Rotation

• ROTATE_0: No rotation.

• ROTATE_90: Rotate coordinates 90 degrees.

• ROTATE_180: Rotate coordinates 180 degrees.

• ROTATE_270: Rotate coordinates 270 degrees.

4.3 Touch device Type

• TYPE_CST328: CanMV Drive Touch

• TYPE_CST226SE: CanMV Drive Touch

• TYPE_GT911: CanMV Drive Touch