RAK14002 Capacitive Touch Button

Based on SparkFun Qwiic Capacitive Touch Slider - CAP1203.
Changed to work with the CAP1293 touch pad chip.

RAKwireless RAK14002 Capacitive Touch Button

Arduino library for the I2C based capacitive touch pad module with 3 unique touch inputs.

Documentation

• Product Repository - Product repository for the RAKWireless RAK14002 Capacitive Touch Pad.
• Documentation - Documentation and Quick Start Guide for the RAK14002 Capacitive Touch Pad.

Installation

In Arduino IDE open Sketch->Include Library->Manage Libraries then search for RAK14002.

In PlatformIO open PlatformIO Home, switch to libraries and search for RAK14002. Or install the library project depend by adding

lib_deps =
  rakwireless/RAKwireless CAP1293 Touch Pad library

into platformio.ini

For manual installation download the archive, unzip it and place the RAK14002-CAP1293-Library folder into the library directory.
In Arduino IDE this is usually /libraries/
In PlatformIO this is usually <user/.platformio/lib>

Usage

The library provides a CAP1293 class, which allows communication to the CAP1293 touch button controller IC. Check out the examples how to use the library.

This class provides the following methods:

CAP1293(byte addr = CAP1293_I2C_ADDR);
Constructor for CAP1293 interface. Initialize touch button controller object
Parameters:

Direction	Name	Function
in	addr	I2C address of CAP1293
return		none

bool begin(TwoWire &wirePort = Wire, uint8_t deviceAddress = CAP1293_I2C_ADDR);
Initialize the library. Optional parameters for device specific I2C bus and I2C address.
Parameters:

Direction	Name	Function
in	wirePort	Hardware I2C port
in	deviceAddress	I2C address of CAP1293
return		Returns true if CAP1293 was detected. Otherwise returns false.

bool isConnected();`
Check if touch button module is connected.
Parameters:

Direction	Name	Function
return		Returns true if the I2C Device acknowledges a connection. Otherwise returns false.

void setSensitivity(uint8_t sensitivity);
Sensitivity control. You may want to change sensitivity settings if creating your own capacitive touch pads. See datasheet on Sensitivity Control Register
Parameters:

Direction	Name	Function
in	sensitivity	Sensitivity (see below list)
return		void

Sensitivity level	Defined name	Value
Highest sensitivity	SENSITIVITY_128X	0x00
High sensitivity	SENSITIVITY_64X	0x01
Higher sensitivity	SENSITIVITY_32X	0x02
Medium sensitivity	SENSITIVITY_16X	0x03
Lower sensitivity	SENSITIVITY_8X	0x04
Low sensitivity	SENSITIVITY_4X	0x05
Low sensitivity	SENSITIVITY_2X	0x06
Lowest sensitivity	SENSITIVITY_1X	0x07

uint8_t getSensitivity();
Returns the current sensitivity sensitivity settings
Parameters:

Direction	Name	Function
return		Sensitivity level (see below list)

Sensitivity level	Defined name	Value
Highest sensitivity	SENSITIVITY_128X	0x00
High sensitivity	SENSITIVITY_64X	0x01
Higher sensitivity	SENSITIVITY_32X	0x02
Medium sensitivity	SENSITIVITY_16X	0x03
Lower sensitivity	SENSITIVITY_8X	0x04
Low sensitivity	SENSITIVITY_4X	0x05
Low sensitivity	SENSITIVITY_2X	0x06
Lowest sensitivity	SENSITIVITY_1X	0x07

Single Touch Functions

bool isLeftTouched();
Checks if touch input detected on left sensor (pad 1). It is required to clear the interrupt pin after touch occurs. See datasheet on Sensor Interrupt Status Reg
Parameters:

Direction	Name	Function
return		True of touch was detected, otherwise false

bool isMiddleTouched();
Checks if touch input detected on middle sensor (pad 2). It is required to clear the interrupt pin after touch occurs. See datasheet on Sensor Interrupt Status Reg
Parameters:

Direction	Name	Function
return		True of touch was detected, otherwise false

bool isRightTouched();
Checks if touch input detected on right sensor (pad 3). It is required to clear the interrupt pin after touch occurs. See datasheet on Sensor Interrupt Status Reg
Parameters:

Direction	Name	Function
return		True of touch was detected, otherwise false

bool isTouched();
Checks if touch input detected on any of the sensors. It is required to clear the interrupt pin after touch occurs. See datasheet on Sensor Interrupt Status Reg
Parameters:

Direction	Name	Function
return		True of touch was detected, otherwise false

uint8_t getTouchKeyStatus(bool keyStatus[], uint8_t num=3);
Checks for changes on the touch status of all three pads.
Parameters:

Direction	Name	Function
out	keyStatus	boolean array to hold the status of the three buttons
in	num	size of boolean array keyStatus
return	uint8_t	0 if the status of all pads is unchanged or > 0 if any pad status has changed

The status is returned in bool keyStatus[], where
keyStatus[0] = true if left button is touched, else false
keyStatus[1] = true if middle button is touched, else false
keyStatus[2] = true if right button is touched, else false
Return value is 0 if the status of all pads is unchanged or > 0 if any pad status has changed.

Swipe Detect Functions

bool isRightSwipePulled();
Checks if a right swipe occurred on the board. This method is blocking and waits for 100ms to detect the start of a swipe motion.
Parameters:

Direction	Name	Function
in	num	size of boolean array keyStatus
return	bool	True if right swipe was detected

bool isLeftSwipePulled();
Checks if a left swipe occurred on the board. This method is blocking and waits for 100ms to detect the start of a swipe motion.
Parameters:

Direction	Name	Function
in	num	size of boolean array keyStatus
return	bool	True if left swipe was detected

Interrupt Control functions

void clearInterrupt();
Clears the interrupt (INT) bit by writing a logic 0 to it. This bit must be cleared in order to detec a new capacitive touch input. See datasheet on Main Control Register

void setInterruptDisabled();
This disables all the interrupts, so the interrupt line is not set when a sensor is touched. Set on default in begin() function. See data sheet on Interrupt Enable Register

void setInterruptEnabled();
This turns on all the interrupts, so the interrupt line is set when any sensor is touched. See data sheet on Interrupt Enable Register.

bool isInterruptEnabled();
Returns state of interrupt pin. Returns true if all interrupts enabled (0x07), otherwise returns false.
Parameters:

Direction	Name	Function
return	bool	True if all interrupts enabled, otherwise returns false

void setReleaseInterruptDisabled();
Disable interrupt on touch release.

void setReleaseInterruptEnabled();
Enable interrupt on touch release.

bool isReleaseInterruptEnabled();
Get current status of touch release interrupt. Returns true if interrupt on touch release is enabled, otherwise false.
Parameters:

Direction	Name	Function
return	bool	True if touch release interrupt is enabled, otherwise false

Sleep Functions

void setDeepSleepDisabled();
Wake sensor up from deep sleep status.

void setDeepSleepEnabled();
Put sensor in deep sleep status. In deep sleep no touch events are detected.

bool isDeepSleepEnabled();
Check if sensor is in deep sleep. Returns true if sensor is in deep sleep, otherwise false.
Parameters:

Direction	Name	Function
return	bool	True if sensor is in deep sleep, otherwise false

Status Functions

uint8_t checkMainControl();
Control the primary power state of the device. See data sheet on Main Control Register.
Returns content of power status register Parameters:

Direction	Name	Function
return	uint8_t	Content of power status register

uint8_t checkStatus();
Checks inputs in the general status register to ensure program is set up correctly. See data sheet on Status Registers Parameters:

Direction	Name	Function
return	uint8_t	Content of status register

Power Button Functions

bool setPowerButtonPad(uint8_t pad);
Sets a specific pad to act as a power button. Function parameter defines the pad. Allowed values PWR_CS1 (left), PWR_CS2 (middle), PWR_CS3 (right). See datasheet on Power Button
Parameters:

Direction	Name	Function
in	pad	Pad to be used as power button
return	bool	True if success, false if invalid pad number was given

bool setPowerButtonTime(uint8_t time);
Configure the length of time that the designated power button must indicate a touch before an interrupt is generated and the power status indicator is set. See data sheet on Power Button Configuration Register.
Possible inputs (represent time in ms): 280, 560, 1120, 2240
Parameters:

Direction	Name	Function
in	time	Power button detection time
return	bool	True if success, false if invalid time was given

uint8_t getPowerButtonPad();
Returns which capacitive touch pad is currently set to act as a power button. Returned values are PWR_CS1 (left), PWR_CS2 (middle) or PWR_CS3 (right) Parameters:

Direction	Name	Function
return	uint8_t	Pad number currently assigned as power button

uint16_t getPowerButtonTime();
Returns the length of the time designated time power button must indicate a touch before an interrupt is generated. Return value is in milliseconds. Parameters:

Direction	Name	Function
return	uint16_t	Power button detect time in milli seconds

void setPowerButtonEnabled();
Enables power button in active state. See data sheet on Power Button Configuration Register

void setPowerButtonDisabled(); Disables power button in active state. See data sheet on Power Button Configuration Register

bool isPowerButtonEnabled();
Returns state of power button. Returns true if enabled, otherwise returns false.See data sheet on Power Button Configuration Register
Parameters:

Direction	Name	Function
return	bool	True if enabled, otherwise returns false

bool isPowerButtonTouched();
Once the power button has been held for designated time, an interrupt is generated and PWR bit is set in the General Status Register. See data sheet on Power Button, Power Button Register, and Power Button Configuration Register
Parameters:

Direction	Name	Function
return	bool	True if button was touched, otherwise returns false

Multi Touch Functions

void setMultiTouchEnabled();
Enables multi touch detection. See datasheet on Sensor Interrupt Status

void setMultiTouchDisabled();
Disables multi touch detection. See datasheet on Sensor Interrupt Status

Calibration Functions

void setForceCalibrateEnabled();
Enable automatic force calibration. See data sheet on CALIBRATION_ACTIVATE_AND_STATUS register

void setForceCalibrateDisabled();
Disable automatic force calibration. See data sheet on CALIBRATION_ACTIVATE_AND_STATUS register

Repeat Control Functions

void setRepeatRateEnabled();
Enables the repeat rate of the sensor inputs. See data sheet on REPEAT RATE ENABLE register

void setRepeatRateDisabled();
Disables the repeat rate of the sensor inputs. See data sheet on REPEAT RATE ENABLE register

Multi Touch Pattern Functions

void setMTPEnabled(bool left=true, bool middle=true, bool right=true);
Enables multi touch pattern detection. Parameters left, middle and right define which pads are used for the multi touch pattern detection.
Parameters:

Direction	Name	Function
in	left	True => use left button for MTP, false => ignore left button
in	middle	True => use middle button for MTP, false => ignore middle button
in	right	True => use right button for MTP, false => ignore right button

bool isMTPStatus();
Checks if multi touch pattern was detected.
Returns true if the pattern was detected, otherwise false.
Parameters:

Direction	Name	Function
return	bool	True if MTP was touched, otherwise returns false

License Information

This library is based on SparkFun Qwiic Capacitive Touch Slider - CAP1203 which is published under MIT license. See original license in the Sparkfun repository