Library Description

The library initializes and defines SPI bus driver and driver functions which offer a choice to write data in registers and to read data from registers. The library also offers a choice to detect touch on enabled sensor inputs in two possible modes, Active and Standby mode. Sensor inputs can also be configured to detect when touch is released and can generate an interrupt as long as the touch is detected. For more details check the documentation.

Key functions:

void captouch2_writeReg( const uint8_t register_address, const uint8_t transfer_data ) - The function writes one byte to register.

void captouch2_readReg( const uint8_t register_address, uint8_t *dataOut, const uint8_t nBytes ) - The function reads data from the register.

void captouch2_detectTouch( uint8_t *inputSens ) - The function detects touch on sensor inputs and checks if touch is detected or if touch is released.

void captouch2_setActiveMode( const uint8_t analogGain, const uint8_t enInput ) - Function puts device in Active mode and enables desired inputs in Active mode.

Examples Description

The demo application is composed of three sections:

• System Initialization - Initializes peripherals and pins.
• Application Initialization - Initializes SPI driver and sets configuration for Cap Touch 2 click. Cap Touch 2 is configured to works in Active mode (Normal mode). All inputs are enabled in this mode. In this example, the interrupt will be generated when touch is detected and when touch is released. Also, inputs 4, 5 and 6 will generate an interrupt as long as the touch is detected (press and hold event), while inputs 1, 2 and 3 will generate interrupt only once on one touch detection, after which the touch will be released.
  Note: Standby mode should be used when fewer sensor inputs are enabled, and when they are programmed to have more sensitivity.
• Application Task - (code snippet) - Calls function to check touch detection (is interrupt occurred) and shows a message on USB UART on which input touch is detected or on which input touch is released. Also turns on LED on which linked input interrupt occurred.
   

void applicationTask()
{
 captouch2_detectTouch( &sensorResults[0] );
 for (cnt = 0; cnt < 6; cnt++)
 {
 if (sensorResults[ cnt ] == 1)
 {
 if (cnt == 0)
 mikrobus_logWrite( "Input 1 is touched", _LOG_LINE );
 else if (cnt == 1)
 mikrobus_logWrite( "Input 2 is touched", _LOG_LINE );
 else if (cnt == 2)
 mikrobus_logWrite( "Input 3 is touched", _LOG_LINE );
 else if (cnt == 3)
 mikrobus_logWrite( "Input 4 is touched", _LOG_LINE );
 else if (cnt == 4)
 mikrobus_logWrite( "Input 5 is touched", _LOG_LINE );
 else
 mikrobus_logWrite( "Input 6 is touched", _LOG_LINE );
 }
 else if (sensorResults[ cnt ] == 2)
 {
 if (cnt == 0)
 mikrobus_logWrite( "Input 1 is released", _LOG_LINE );
 else if (cnt == 1)
 mikrobus_logWrite( "Input 2 is released", _LOG_LINE );
 else if (cnt == 2)
 mikrobus_logWrite( "Input 3 is released", _LOG_LINE );
 else if (cnt == 3)
 mikrobus_logWrite( "Input 4 is released", _LOG_LINE );
 else if (cnt == 4)
 mikrobus_logWrite( "Input 5 is released", _LOG_LINE );
 else
 mikrobus_logWrite( "Input 6 is released", _LOG_LINE );
 mikrobus_logWrite( "", _LOG_LINE );
 }
 }
}

Other mikroE libraries used in the example:

• SPI
• UART

Additional notes and information

Depending on the development board you are using, you may need USB UART click,  USB UART 2 click or  RS232 click to connect to your PC, for development systems with no UART to USB interface available on the board. The terminal available in all MikroElektronika compilers, or any other terminal application of your choice, can be used to read the message.