Unlock new dimensions of control with TTP224 and PIC18F57Q43
Begin with a simple touch
Published Feb 13, 2024
Click board™
TouchKey Click
Dev. board
Curiosity Nano with PIC18F57Q43
Compiler
NECTO Studio
MCU
PIC18F57Q43
Explore the possibilities of capacitive touch sensing and create interfaces that redefine user interactions
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Hardware Overview
How does it work?
TouchKey Click is based on the TTP224, a four key touch pad detector from TonTouch. The TTP224 has a stable sensing method that can cover diverse conditions and acts as a human interface control panel through non-conductive dielectric materials. It features auto-calibration for life, with a re-calibration period of about 4 seconds when a key has not been touched. The TouchKey Click can detect all four pad activations at once. There are two operating modes: Low Power and Fast mode. Unlike the low-power operating mode, which has a slower response for the first touch, the Fast mode, in addition to a much faster response, also has a slightly higher consumption. When working in Fast mode, if no touch is detected after 8 seconds, the board automatically switches to Low
Power mode. The TouchKey Click has four pads labeled A, B, C, and D. To communicate with the host MCU, the TTP224 uses four digital inputs of the mikroBUS™ socket, labeled just as the pads above, A, B, C, and D. Every touch on the corresponding pad will send the digital state to its assigned pin. The TTP224 has various features that can be addressed on this Click board™ over four solder jumpers. The Low Power or Fast mode option can be set over an LPMB solder jumper (Low Power as a default), while the TOG jumper sets output mode, direct or toggle (direct as a default). Depending on the output state needs, this Click board™ can use active High or Low over the AHLB solder jumper, where the active High is set by default. Objects used to cover the sensor
pads can cause a change in sensing detection. To prevent this change, the maximum key duration time can be set from 16 seconds to infinite via the MOT0 solder jumper (infinite is set as default). Open drain or CMOS output can also be set via the OD solder jumper, with CMOS as the default. The last is an SM solder jumper used to set single or multi-key options, with the multi-key set as the default. This Click board™ can operate with either 3.3V or 5V logic voltage levels selected via the PWR SEL jumper. This way, both 3.3V and 5V capable MCUs can use the communication lines properly. Also, this Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used as a reference for further development.
Features overview
Development board
PIC18F57Q43 Curiosity Nano evaluation kit is a cutting-edge hardware platform designed to evaluate microcontrollers within the PIC18-Q43 family. Central to its design is the inclusion of the powerful PIC18F57Q43 microcontroller (MCU), offering advanced functionalities and robust performance. Key features of this evaluation kit include a yellow user LED and a responsive
mechanical user switch, providing seamless interaction and testing. The provision for a 32.768kHz crystal footprint ensures precision timing capabilities. With an onboard debugger boasting a green power and status LED, programming and debugging become intuitive and efficient. Further enhancing its utility is the Virtual serial port (CDC) and a debug GPIO channel (DGI
GPIO), offering extensive connectivity options. Powered via USB, this kit boasts an adjustable target voltage feature facilitated by the MIC5353 LDO regulator, ensuring stable operation with an output voltage ranging from 1.8V to 5.1V, with a maximum output current of 500mA, subject to ambient temperature and voltage constraints.
Microcontroller Overview
MCU Card / MCU
Architecture
PIC
MCU Memory (KB)
128
Silicon Vendor
Microchip
Pin count
48
RAM (Bytes)
8196
You complete me!
Accessories
Curiosity Nano Base for Click boards is a versatile hardware extension platform created to streamline the integration between Curiosity Nano kits and extension boards, tailored explicitly for the mikroBUS™-standardized Click boards and Xplained Pro extension boards. This innovative base board (shield) offers seamless connectivity and expansion possibilities, simplifying experimentation and development. Key features include USB power compatibility from the Curiosity Nano kit, alongside an alternative external power input option for enhanced flexibility. The onboard Li-Ion/LiPo charger and management circuit ensure smooth operation for battery-powered applications, simplifying usage and management. Moreover, the base incorporates a fixed 3.3V PSU dedicated to target and mikroBUS™ power rails, alongside a fixed 5.0V boost converter catering to 5V power rails of mikroBUS™ sockets, providing stable power delivery for various connected devices.
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Click board™ Schematic
Step by step
Project assembly
Start by selecting your development board and Click board™. Begin with the Curiosity Nano with PIC18F57Q43 as your development board.
Track your results in real time
Application Output
1. Application Output - In Debug mode, the 'Application Output' window enables real-time data monitoring, offering direct insight into execution results. Ensure proper data display by configuring the environment correctly using the provided tutorial.
2. UART Terminal - Use the UART Terminal to monitor data transmission via a USB to UART converter, allowing direct communication between the Click board™ and your development system. Configure the baud rate and other serial settings according to your project's requirements to ensure proper functionality. For step-by-step setup instructions, refer to the provided tutorial.
3. Plot Output - The Plot feature offers a powerful way to visualize real-time sensor data, enabling trend analysis, debugging, and comparison of multiple data points. To set it up correctly, follow the provided tutorial, which includes a step-by-step example of using the Plot feature to display Click board™ readings. To use the Plot feature in your code, use the function: plot(*insert_graph_name*, variable_name);. This is a general format, and it is up to the user to replace 'insert_graph_name' with the actual graph name and 'variable_name' with the parameter to be displayed.
Software Support
Library Description
This library contains API for TouchKey Click driver.
Key functions:
touchkey_a- This function gets state of "a" (RST) pin on TouchKey Clicktouchkey_b- This function gets state of "b" (AN) pin on TouchKey Clicktouchkey_c- This function gets state of "c" (PWM) pin on TouchKey Clicktouchkey_d- This function gets state of "d" (INT) pin on TouchKey Click
Open Source
Code example
The complete application code and a ready-to-use project are available through the NECTO Studio Package Manager for direct installation in the NECTO Studio. The application code can also be found on the MIKROE GitHub account.
/*!
* \file
* \brief TouchKey Click example
*
* # Description
* This application has four capacitive pads powered by TTP224, a touchpad detector IC.
* Capacitive buttons like these can be toggled even when placed under a layer of glass or paper.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initialization driver enables GPIO and also starts write log.
*
* ## Application Task
* This example demonstrates the use of TouchKey Click board.
* Detects whether any of the keys is pressed. Results are being sent to the Usart Terminal,
* where you can track changes.
*
* \author MikroE Team
*
*/
// ------------------------------------------------------------------- INCLUDES
#include "board.h"
#include "log.h"
#include "touchkey.h"
// ------------------------------------------------------------------ VARIABLES
static touchkey_t touchkey;
static log_t logger;
static uint8_t key_state = 0;
static uint8_t key_state_old = 1;
// ------------------------------------------------------ APPLICATION FUNCTIONS
void application_init ( void )
{
log_cfg_t log_cfg;
touchkey_cfg_t cfg;
/**
* Logger initialization.
* Default baud rate: 115200
* Default log level: LOG_LEVEL_DEBUG
* @note If USB_UART_RX and USB_UART_TX
* are defined as HAL_PIN_NC, you will
* need to define them manually for log to work.
* See @b LOG_MAP_USB_UART macro definition for detailed explanation.
*/
LOG_MAP_USB_UART( log_cfg );
log_init( &logger, &log_cfg );
log_info( &logger, "---- Application Init ----" );
// Click initialization.
touchkey_cfg_setup( &cfg );
TOUCHKEY_MAP_MIKROBUS( cfg, MIKROBUS_1 );
touchkey_init( &touchkey, &cfg );
log_printf( &logger, "Press key\r\n" );
}
void application_task ( void )
{
key_state = touchkey_a( &touchkey ) | touchkey_b( &touchkey ) | touchkey_c( &touchkey ) | touchkey_d( &touchkey );
if( key_state == 1 && key_state_old == 0 )
{
log_printf( &logger,"Pressed : " );
if( touchkey_a( &touchkey ) )
{
log_printf( &logger, "A\r\n " );
}
if( touchkey_b( &touchkey) )
{
log_printf( &logger, "B\r\n " );
}
if( touchkey_c( &touchkey ) )
{
log_printf( &logger, "C\r\n " );;
}
if( touchkey_d( &touchkey ) )
{
log_printf( &logger, "D\r\n " );
}
key_state_old = 1;
}
if ( key_state == 0 && key_state_old == 1 )
{
key_state_old = 0;
}
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END
