Intermediate
30 min

Enable swift navigation, gaming, and content control with ATSAML10 and ATmega32

Touch, slide, and elevate your experience!

SAML Touch Click with EasyAVR v7

Published Nov 01, 2023

Click board™

SAML Touch Click

Dev. board

EasyAVR v7

Compiler

NECTO Studio

MCU

ATmega32

Designed to empower user creativity and productivity, the purpose of our solution lies in its ability to offer multiple touch points and a slider for seamless, gesture-based control, enhancing the overall user experience

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Hardware Overview

How does it work?

SAML Touch Click is based on the ATSAML10, an ultra-low power 32-bit ARM® Cortex® MicroController Unit (MCU) from Microchip. Among many other features, this MCU contains the enhanced Peripheral Touch Controller (PTC) module, making it a perfect solution for various capacitive touch-based applications that require superior noise immunity. One of the key features of the PTC module is its ability to sense touch events reliably, even when covered with water. SAML click demonstrates the overall hardware simplicity of one such application: capacitive pads are directly connected to the MCU pins, with no additional components required. Everything is already integrated within the PTC module of the ATSAML10 MCU itself, allowing fast development. The only passive components on this click are the resistors that limit the current through the LEDs, and accompanying filtering capacitors.

As mentioned, the enhanced PTC module provides many benefits over similar solutions. The most distinctive is its parallel acquisition capability, allowing it to process all the inputs in parallel and simultaneously detect multiple touch events. This increases the responsiveness of the touch interface compared to traditional sequential acquisition circuits. It also improves noise immunity and robustness when used in harsh and humid environments. This allows the Click board™ to use an acrylic overlay and still accurately detect touch events. Another feature of the enhanced PTC module is the Driven Shield Plus capability. This capability adds another layer of noise protection to the application. It allows touch sensors to work while exposed to moisture, sweat, rain, and even running water. Any capacitive touch channel can be used as a driven shield channel, offering IP-68-compliant protection.

A cleverly designed firmware is responsible for event detection, visual feedback over LED indicators, and communication with the host MCU. The MCU firmware is written using Q-Touch® libraries from Microchip, which offer full support for PTC modules. The communication with the ATSAML10 is realized over the UART interface. A set of UART command strings are available for touch detection and the touch slider position. However, the Click board™ is supported by a mikroSDK compatible library, offering simple functions, saving the developer to write UART command parsers. These functions allow faster development and simplified software design. The Click board™ is designed to work with 3.3V only. If interfacing with systems that use 5V for their operation, an appropriate level of translating circuitry has to be used.

SAML Touch Click top side image
SAML Touch Click bottom side image

Features overview

Development board

EasyAVR v7 is the seventh generation of AVR development boards specially designed for the needs of rapid development of embedded applications. It supports a wide range of 16-bit AVR microcontrollers from Microchip and has a broad set of unique functions, such as a powerful onboard mikroProg programmer and In-Circuit debugger over USB. The development board is well organized and designed so that the end-user has all the necessary elements in one place, such as switches, buttons, indicators, connectors, and others. With four different connectors for each port, EasyAVR v7 allows you to connect accessory boards, sensors, and custom electronics more

efficiently than ever. Each part of the EasyAVR v7 development board contains the components necessary for the most efficient operation of the same board. An integrated mikroProg, a fast USB 2.0 programmer with mikroICD hardware In-Circuit Debugger, offers many valuable programming/debugging options and seamless integration with the Mikroe software environment. Besides it also includes a clean and regulated power supply block for the development board. It can use a wide range of external power sources, including an external 12V power supply, 7-12V AC or 9-15V DC via DC connector/screw terminals, and a power source via the USB Type-B (USB-B)

connector. Communication options such as USB-UART and RS-232 are also included, alongside the well-established mikroBUS™ standard, three display options (7-segment, graphical, and character-based LCD), and several different DIP sockets which cover a wide range of 16-bit AVR MCUs. EasyAVR v7 is an integral part of the Mikroe ecosystem for rapid development. Natively supported by Mikroe software tools, it covers many aspects of prototyping and development thanks to a considerable number of different Click boards™ (over a thousand boards), the number of which is growing every day.

EasyAVR v7 horizontal image

Microcontroller Overview

MCU Card / MCU

default

Architecture

AVR

MCU Memory (KB)

32

Silicon Vendor

Microchip

Pin count

40

RAM (Bytes)

2048

Used MCU Pins

mikroBUS™ mapper

NC
NC
AN
NC
NC
RST
NC
NC
CS
NC
NC
SCK
NC
NC
MISO
NC
NC
MOSI
Power Supply
3.3V
3.3V
Ground
GND
GND
NC
NC
PWM
NC
NC
INT
UART TX
PD1
TX
UART RX
PD0
RX
NC
NC
SCL
NC
NC
SDA
NC
NC
5V
Ground
GND
GND
1

Take a closer look

Click board™ Schematic

SAML Touch Click Schematic schematic

Step by step

Project assembly

EasyAVR v7 front image hardware assembly

Start by selecting your development board and Click board™. Begin with the EasyAVR v7 as your development board.

EasyAVR v7 front image hardware assembly
GNSS2 Click front image hardware assembly
EasyAVR v7 Access DIP MB 1 - upright/background hardware assembly
Necto image step 2 hardware assembly
Necto image step 3 hardware assembly
Necto image step 4 hardware assembly
NECTO Compiler Selection Step Image hardware assembly
NECTO Output Selection Step Image hardware assembly
Necto image step 6 hardware assembly
Necto DIP image step 7 hardware assembly
EasyPIC PRO v7a Display Selection Necto Step hardware assembly
Necto image step 9 hardware assembly
Necto image step 10 hardware assembly
Necto PreFlash Image hardware assembly

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 SAML Touch Click driver.

Key functions:

  • samltouch_generic_write - Generic write function

  • samltouch_generic_read - Generic read function

  • samltouch_parser - Generic parser function

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 SamlTouch Click example
 * 
 * # Description
 * This example reads and processes data from SAML Touch clicks.
 *
 * The demo application is composed of two sections :
 * 
 * ## Application Init 
 * Initializes driver.
 * 
 * ## Application Task  
 * Reads the received data and parses it.
 * 
 * ## Additional Function
 * - samltouch_process ( ) - The general process of collecting data the module sends.
 * 
 * \author MikroE Team
 *
 */
// ------------------------------------------------------------------- INCLUDES

#include "board.h"
#include "log.h"
#include "samltouch.h"
#include "string.h"

#define PROCESS_RX_BUFFER_SIZE 1000
#define PROCESS_BUFFER_SIZE 80

// ------------------------------------------------------------------ VARIABLES

static samltouch_t samltouch;
static log_t logger;

samltouch_state_t saml_touch_status;

static char uart_rx_buffer[ PROCESS_RX_BUFFER_SIZE ] = { 0 };
static char current_parser_buffer[ PROCESS_BUFFER_SIZE ];

static uint8_t flag_1 = 0;
static uint8_t flag_2 = 0;
static uint16_t wait_cnt = 0;
static uint16_t button1_cnt = 0;
static uint16_t button2_cnt = 0;

// ------------------------------------------------------- ADDITIONAL FUNCTIONS

static void samltouch_process ( void )
{
    int32_t rsp_size;
    uint16_t check_buf_cnt;
    
    // Clear RX buffer
    memset( uart_rx_buffer, 0, PROCESS_RX_BUFFER_SIZE );
    // Clear Parser buffer
    memset( current_parser_buffer, 0, PROCESS_BUFFER_SIZE );
    
    rsp_size = samltouch_generic_read( &samltouch, uart_rx_buffer, PROCESS_RX_BUFFER_SIZE );
    
    if ( rsp_size > 0 )
    {  
        for ( check_buf_cnt = 0; check_buf_cnt < rsp_size; check_buf_cnt++ ) {
            if ( uart_rx_buffer[check_buf_cnt] == SAMLTOUCH_START_FRAME && ( (check_buf_cnt + 76) <= rsp_size ) ) {
                memcpy( current_parser_buffer, &uart_rx_buffer[check_buf_cnt], 76 );
                if ( current_parser_buffer[ 10 ] == 1 ) 
                {
                    button1_cnt++;
                }
                if ( current_parser_buffer[ 20 ] == 1 ) 
                {
                    button2_cnt++;
                }
                flag_1 = 1;
                break;
            }
        }
    }
}

void parser_application ( )
{
    samltouch_process( );

    if ( flag_1 == 1 )
    {
        samltouch_parser( current_parser_buffer, &saml_touch_status );
        
        flag_2 = 0;
        
        if ( saml_touch_status.button2 == 1 && button2_cnt > 2 )
        {
            log_printf( &logger, "\r\n Button 2 is pressed. \r\n" );
            flag_2 = 1;
            wait_cnt = 0;
            button2_cnt = 2;
        }
        
        if ( saml_touch_status.button1 == 1 && button1_cnt > 2 )
        {
            log_printf( &logger, "\r\n Button 1 is pressed. \r\n" );
            flag_2 = 1;
            wait_cnt = 0;
            button1_cnt = 2;
        }
        
        if ( saml_touch_status.sw_state == 1 && saml_touch_status.sw_pos != 0 )
        {
            log_printf( &logger, "\r\n Slider position is  %u \r\n", (uint16_t) saml_touch_status.sw_pos );
            flag_2 = 1;
            wait_cnt = 0;
        }
        flag_1 = 0;
    }
     
    if ( flag_2 == 1 ) 
    {
        Delay_100ms( );
    }
    else 
    {
        if ( wait_cnt++%50 == 0 )
        {
            log_printf( &logger, "\r\n Waiting for an event: \r\n" );
            button1_cnt = 0;
            button2_cnt = 0;
        }
        log_printf( &logger, "." );
        Delay_100ms( );
    }
}

// ------------------------------------------------------ APPLICATION FUNCTIONS

void application_init ( void )
{
    log_cfg_t log_cfg;
    samltouch_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.

    samltouch_cfg_setup( &cfg );
    SAMLTOUCH_MAP_MIKROBUS( cfg, MIKROBUS_1 );
    samltouch_init( &samltouch, &cfg );
    
    Delay_ms( 500 );
}

void application_task ( void )
{
    parser_application( );
}

void main ( void )
{
    application_init( );

    for ( ; ; )
    {
        application_task( );
    }
}

// ------------------------------------------------------------------------ END

Additional Support

Resources

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