This capacitive solution aims to revolutionize user interaction, providing a responsive and intuitive means to control devices with a simple touch
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Hardware Overview
How does it work?
Cap Wheel 2 Click is based on the IQS263B, ProxSense® IC, a 3-channel projected (or self) capacitive proximity and touch controller from Azoteq. This IC has advanced features such as auto drift compensation, up to 80Hz report rate, long proximity range, automatic adjustment for optimal performance (ATI), and a configurable 8-bit 2/3 channel slider or 3-channel scroll wheel. These features enable CAP Wheel 2 click to exhibit reliable and accurate touch detection. Capacitive touch sensing is based on detecting a change in capacitance due to the influence of a foreign
object. The capacitance of the sensor, also known as the antenna, is measured and monitored, and if a significant change occurs after processing by the detection integrator, a touch event is acknowledged. CAP Wheel 2 Click is designed with these requirements in mind, and the electrodes are „Self-Capacitive Wheel“ shaped. The IQS263B IC interfaces to a master controller via a 3-wire (SDA, SCL, and RDY) serial interface bus that is I2C™ compatible, with a maximum communication speed of 400kbit/s. The host MCU can force communication anytime by pulling the
RDY line low. The communication will start directly following the current conversion cycle. If the watchdog timer terminates the event, the device will reset. After every power-on cycle, the device will recalibrate itself. It will take some time, so it should be considered when building custom applications. MikroElektronika provides libraries and the demo application to be used as a reference for future designs. As mentioned before, this Click board™ is I2C compatible and uses SCL, SDA, and RDY pins for communication routed to SCL, SDA, and INT pins on mikroBUS™.
Features overview
Development board
Nucleo-64 with STM32G071RB MCU offers a cost-effective and adaptable platform for developers to explore new ideas and prototype their designs. This board harnesses the versatility of the STM32 microcontroller, enabling users to select the optimal balance of performance and power consumption for their projects. It accommodates the STM32 microcontroller in the LQFP64 package and includes essential components such as a user LED, which doubles as an ARDUINO® signal, alongside user and reset push-buttons, and a 32.768kHz crystal oscillator for precise timing operations. Designed with expansion and flexibility in mind, the Nucleo-64 board features an ARDUINO® Uno V3 expansion connector and ST morpho extension pin
headers, granting complete access to the STM32's I/Os for comprehensive project integration. Power supply options are adaptable, supporting ST-LINK USB VBUS or external power sources, ensuring adaptability in various development environments. The board also has an on-board ST-LINK debugger/programmer with USB re-enumeration capability, simplifying the programming and debugging process. Moreover, the board is designed to simplify advanced development with its external SMPS for efficient Vcore logic supply, support for USB Device full speed or USB SNK/UFP full speed, and built-in cryptographic features, enhancing both the power efficiency and security of projects. Additional connectivity is
provided through dedicated connectors for external SMPS experimentation, a USB connector for the ST-LINK, and a MIPI® debug connector, expanding the possibilities for hardware interfacing and experimentation. Developers will find extensive support through comprehensive free software libraries and examples, courtesy of the STM32Cube MCU Package. This, combined with compatibility with a wide array of Integrated Development Environments (IDEs), including IAR Embedded Workbench®, MDK-ARM, and STM32CubeIDE, ensures a smooth and efficient development experience, allowing users to fully leverage the capabilities of the Nucleo-64 board in their projects.
Microcontroller Overview
MCU Card / MCU
Architecture
ARM Cortex-M0
MCU Memory (KB)
128
Silicon Vendor
STMicroelectronics
Pin count
64
RAM (Bytes)
36864
You complete me!
Accessories
Click Shield for Nucleo-64 comes equipped with two proprietary mikroBUS™ sockets, allowing all the Click board™ devices to be interfaced with the STM32 Nucleo-64 board with no effort. This way, Mikroe allows its users to add any functionality from our ever-growing range of Click boards™, such as WiFi, GSM, GPS, Bluetooth, ZigBee, environmental sensors, LEDs, speech recognition, motor control, movement sensors, and many more. More than 1537 Click boards™, which can be stacked and integrated, are at your disposal. The STM32 Nucleo-64 boards are based on the microcontrollers in 64-pin packages, a 32-bit MCU with an ARM Cortex M4 processor operating at 84MHz, 512Kb Flash, and 96KB SRAM, divided into two regions where the top section represents the ST-Link/V2 debugger and programmer while the bottom section of the board is an actual development board. These boards are controlled and powered conveniently through a USB connection to program and efficiently debug the Nucleo-64 board out of the box, with an additional USB cable connected to the USB mini port on the board. Most of the STM32 microcontroller pins are brought to the IO pins on the left and right edge of the board, which are then connected to two existing mikroBUS™ sockets. This Click Shield also has several switches that perform functions such as selecting the logic levels of analog signals on mikroBUS™ sockets and selecting logic voltage levels of the mikroBUS™ sockets themselves. Besides, the user is offered the possibility of using any Click board™ with the help of existing bidirectional level-shifting voltage translators, regardless of whether the Click board™ operates at a 3.3V or 5V logic voltage level. Once you connect the STM32 Nucleo-64 board with our Click Shield for Nucleo-64, you can access hundreds of Click boards™, working with 3.3V or 5V logic voltage levels.
Used MCU Pins
mikroBUS™ mapper
Take a closer look
Schematic
Step by step
Project assembly
Track your results in real time
Application Output via Debug Mode
1. Once the code example is loaded, pressing the "DEBUG" button initiates the build process, programs it on the created setup, and enters Debug mode.
2. After the programming is completed, a header with buttons for various actions within the IDE becomes visible. Clicking the green "PLAY" button starts reading the results achieved with the Click board™. The achieved results are displayed in the Application Output tab.
Software Support
Library Description
This library contains API for CAP Wheel 2 Click driver.
Key functions:
capwheel2_int_get
- This function gets state of INT pincapwheel2_wait_for_rdy
- This function waits for RDY pin to transition from HIGH to LOW state.
Open Source
Code example
This example can be found in NECTO Studio. Feel free to download the code, or you can copy the code below.
/*!
* \file
* \brief CapWheel2 Click example
*
* # Description
* This example sets basic device configuration; Contains function for waiting RDY(INT) pin, function for getting RDY(INT) pin state,
* function for I2C read and write with waiting for RDY(INT) pin and without waiting for RDY(INT) pin.
*
* The demo application is composed of two sections :
*
* ## Application Init
* Initializes CAP Wheel 2 device
*
* ## Application Task
* Executes one of three 'capwheel2_get_xxx_task( )' functions
*
* Additional Functions :
*
* - capwheel2_error( ) - Logs error message and blocks code execution in endless while loop
* - capwheel2_get_channels_task( ) - Logs active channels in touch and halt bytes ( channels: CH0 - proximity channel, CH1, CH2, CH3 )
* - capwheel2_get_gesture_task( ) - Logs active gestures ( gestures: tap, touch, proximity )
* - capwheel2_get_channel_counts_task( ) - Logs channel count values for each channel
* - capwheel2_get_channels_touch( ) - Logs touch byte active channels ( exectuted by 'capwheel2_get_channels_task( )' function )
* - capwheel2_get_channels_halt( ) - Logs halt byte active channels ( exectuted by 'capwheel2_get_channels_task( )' function )
* \author MikroE Team
*
*/
// ------------------------------------------------------------------- INCLUDES
#include "board.h"
#include "log.h"
#include "capwheel2.h"
// ------------------------------------------------------------------ VARIABLES
static capwheel2_t capwheel2;
static log_t logger;
static uint8_t data_buffer[ 30 ];
static uint16_t channel_0_counts;
static uint16_t channel_1_counts;
static uint16_t channel_2_counts;
static uint16_t channel_3_counts;
// ------------------------------------------------------- ADDITIONAL FUNCTIONS
void capwheel2_error( )
{
log_info( &logger, "> error : reset system" );
while( 1 );
}
void capwheel2_get_channels_touch( )
{
switch ( data_buffer[ 0 ] )
{
case 0x00 :
{
log_printf( &logger, "> | | | < \r\n" );
break;
}
case 0x01 :
{
log_printf( &logger, "> | | | CH0 < \r\n" );
break;
}
case 0x02 :
{
log_printf( &logger, "> | | CH1 | < \r\n" );
break;
}
case 0x03 :
{
log_printf( &logger, "> | | CH1 | CH0 < \r\n" );
break;
}
case 0x04 :
{
log_printf( &logger, "> | CH2 | | < \r\n" );
break;
}
case 0x05 :
{
log_printf( &logger, "> | CH2 | | CH0 < \r\n" );
break;
}
case 0x06 :
{
log_printf( &logger, "> | CH2 | CH1 | < \r\n" );
break;
}
case 0x07 :
{
log_printf( &logger, "> | CH2 | CH1 | CH0 < \r\n" );
break;
}
case 0x08 :
{
log_printf( &logger, "> CH3 | | | < \r\n" );
break;
}
case 0x09 :
{
log_printf( &logger, "> CH3 | | | CH0 < \r\n" );
break;
}
case 0x0A :
{
log_printf( &logger, "> CH3 | | CH1 | < \r\n" );
break;
}
case 0x0B :
{
log_printf( &logger, "> CH3 | | CH1 | CH0 < \r\n" );
break;
}
case 0x0C :
{
log_printf( &logger, "> CH3 | CH2 | | < \r\n" );
break;
}
case 0x0D :
{
log_printf( &logger, "> CH3 | CH2 | | CH0 < \r\n" );
break;
}
case 0x0E :
{
log_printf( &logger, "> CH3 | CH2 | CH1 | < \r\n" );
break;
}
case 0x0F :
{
log_printf( &logger, "> CH3 | CH2 | CH1 | CH0 < \r\n" );
break;
}
default :
{
break;
}
}
}
void capwheel2_get_channels_halt( )
{
switch ( data_buffer[ 1 ] )
{
case 0x00 :
{
log_printf( &logger, "> | | | <\r\n" );
break;
}
case 0x01 :
{
log_printf( &logger, "> | | | CH0 <\r\n" );
break;
}
case 0x02 :
{
log_printf( &logger, "> | | CH1 | <\r\n" );
break;
}
case 0x03 :
{
log_printf( &logger, "> | | CH1 | CH0 <\r\n" );
break;
}
case 0x04 :
{
log_printf( &logger, "> | CH2 | | <\r\n" );
break;
}
case 0x05 :
{
log_printf( &logger, "> | CH2 | | CH0 <\r\n" );
break;
}
case 0x06 :
{
log_printf( &logger, "> | CH2 | CH1 | <\r\n" );
break;
}
case 0x07 :
{
log_printf( &logger, "> | CH2 | CH1 | CH0 <\r\n" );
break;
}
case 0x08 :
{
log_printf( &logger, "> CH3 | | | <\r\n" );
break;
}
case 0x09 :
{
log_printf( &logger, "> CH3 | | | CH0 <\r\n" );
break;
}
case 0x0A :
{
log_printf( &logger, "> CH3 | | CH1 | <\r\n" );
break;
}
case 0x0B :
{
log_printf( &logger, "> CH3 | | CH1 | CH0 <\r\n" );
break;
}
case 0x0C :
{
log_printf( &logger, "> CH3 | CH2 | | <\r\n" );
break;
}
case 0x0D :
{
log_printf( &logger, "> CH3 | CH2 | | CH0 <\r\n" );
break;
}
case 0x0E :
{
log_printf( &logger, "> CH3 | CH2 | CH1 | <\r\n" );
break;
}
case 0x0F :
{
log_printf( &logger, "> CH3 | CH2 | CH1 | CH0 <\r\n" );
break;
}
default :
{
break;
}
}
}
void capwheel2_get_channels_task( )
{
if ( capwheel2_i2c_read_wait( &capwheel2, CAPWHEEL2_TOUCH_BYTES, &data_buffer[ 0 ], 2 ) )
{
capwheel2_error( );
}
log_printf( &logger, " ");
log_printf( &logger, "> TOUCH BYTES <\r\n" );
log_printf( &logger, "> HALT BYTES <\r\n" );
capwheel2_get_channels_touch( );
capwheel2_get_channels_halt( );
Delay_ms( 150 );
}
void capwheel2_get_gesture_task( )
{
if ( capwheel2_i2c_read_wait( &capwheel2, CAPWHEEL2_SYS_FLAGS, &data_buffer[ 0 ], 2 ) )
{
capwheel2_error( );
}
if ( ( data_buffer[ 1 ] & CAPWHEEL2_TAP_MASK ) == CAPWHEEL2_TAP_MASK)
{
log_printf( &logger, "> TAP\r\n" );
}
else if ( ( data_buffer[ 1 ] & CAPWHEEL2_TOUCH_MASK ) == CAPWHEEL2_TOUCH_MASK)
{
log_printf( &logger, "> TOUCH\r\n" );
}
else if ( ( data_buffer[ 1 ] & CAPWHEEL2_PROX_MASK ) == CAPWHEEL2_PROX_MASK)
{
log_printf( &logger, "> PROX\r\n" );
}
Delay_ms( 800 );
}
void capwheel2_get_channel_counts_task( )
{
if (capwheel2_i2c_read_wait( &capwheel2, CAPWHEEL2_COUNTS, &data_buffer[ 0 ], 10))
{
capwheel2_error( );
}
channel_0_counts = data_buffer[ 3 ];
channel_0_counts <<= 8;
channel_0_counts |= data_buffer[ 2 ];
channel_1_counts = data_buffer[ 5 ];
channel_1_counts <<= 8;
channel_1_counts |= data_buffer[ 4 ];
channel_2_counts = data_buffer[ 7 ];
channel_2_counts <<= 8;
channel_2_counts |= data_buffer[ 6 ];
channel_3_counts = data_buffer[ 9 ];
channel_3_counts <<= 8;
channel_3_counts |= data_buffer[ 8 ];
log_printf( &logger, "> Channel 0 counts : %u \r\n", channel_0_counts );
log_printf( &logger, "> Channel 1 counts : %u \r\n", channel_1_counts );
log_printf( &logger, "> Channel 2 counts : %u \r\n", channel_2_counts );
log_info( &logger, " ");
Delay_ms( 150 );
}
// ------------------------------------------------------ APPLICATION FUNCTIONS
void application_init ( void )
{
log_cfg_t log_cfg;
capwheel2_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.
capwheel2_cfg_setup( &cfg );
CAPWHEEL2_MAP_MIKROBUS( cfg, MIKROBUS_1 );
capwheel2_init( &capwheel2, &cfg );
}
void application_task ( void )
{
capwheel2_get_channels_task( );
}
void main ( void )
{
application_init( );
for ( ; ; )
{
application_task( );
}
}
// ------------------------------------------------------------------------ END