MIKROE-2474

TouchKey 2 click PID: MIKROE-2474 TouchKey 2 click has four capacitive pads powered by ATtiny817 which has an integrated touch QTouch® controller. The click is designed to run on a 3.3V power supply. The four LEDs onboard the click indicate when the Key (Pad) is pressed. TouchKey 2 click communicates with the target microcontroller over UART interface (SPI interface is optional). High moisture tolerance You can use TouchKey 2 click in all kinds of conditions, without fearing something will happen to it due to moisture and water droplets falling on it. The plastic overlay on the TouchKey 2 click protects the board from moisture. Thanks to this feature the electronic components are safe. The ATtiny817 has a driven shield for improved moisture and noise handling performance. ATtiny817 features The Atmel® ATtiny817 is a microcontroller that uses an 8-bit AVR® processor with hardware multiplier, running at up to 20MHz and with up to 8KB Flash, 512 bytes of SRAM and 128 bytes of EEPROM. ATtiny817 uses the latest technologies from Atmel® with a flexible and low power architecture including Event System and SleepWalking, accurate analog features and advanced peripherals. Capacitive touch interfaces with proximity sensing and driven shield are supported with the integrated QTouch® peripheral touch controller. The module supports wake-up on touch from power-save sleep mode. Button features Capacitive buttons can be toggled even when placed under a layer of glass or paper. How it works There are four LEDs for four touch keys. If key A is pressed LED_A is ON, etc. In addition, there is UART communication between ATtiny817 and main MCU. Note: The header onboard the TouchKey 2 click can be used for device programming. Current firmware sends data packets via UART (on which the demo example in our library is based). SPI communication is possible with firmware modifications. Key features    ATtiny817 module   o Atmel® AVR® 8‐bit CPU  o Running at up to 20MHz  o 128B EEPROM  o 256/512B SRAM  o 32.768kHz external crystal oscillator  UART interface (SPI optional)  3.3V power supply  Product Type Applications On-board modules Key Features Key Benefits Interface Power Supply Compatibility Click board size Capacitive A replacement for mechanical buttons ATtiny817 from Microchip Four capacitive touch pads, 3.3V power supply, protective plastic overlay High moisture tolerance UART (SPI is optional) 3.3V mikroBUS L (57.15 x 25.4 mm) Pinout diagram This table shows how the pinout on TouchKey 2 click corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns). Notes    Pin  Pin  Notes  mikroBUStm  Not connected  NC  1  AN  PWM 16  NC  Not connected  PC5_TARGET_RES ET  2  RST  INT  15  NC  Not connected  PC3_SPI_SS  3  CS  TX  14  PA1_UART_TXD  UART transmit  PC0_SPI_SCK  4  SCK  RX  13  PA2_UART_TXD  UART receive  SPI Master Input  PC1_SPI_MISO  Slave Output  5  MISO  SCL  12  NC  Not connected  SPI Master Output  PC2_SPI_MOSI  Slave Input  6  MOSI  SDA  11  NC  Not connected  Not connected  Reset  SPI Chip Select  SPI Clock  Power supply  +3.3V  7  3.3V  5V  10  NC  Ground  GND  8  GND  GND  9  GND  Buttons and LEDs Designator  Name  Type (LED,  BUTTON…)  Description  PWR  PWR  LED  Power Supply Indication LED.  LD1  A  LED  Key A Press Indication LED  LD2  B  LED  Key B Press Indication LED  LD3  C  LED  Key C Press Indication LED  Ground  LD4  D  LED  Key D Press Indication LED  J1  PDI  Header  Programming header  Maximum ratings Description  Min  Typ  Max  Unit  Power Supply Voltage  ‐0.5  3.3  6  V  Current into VDD pin  ‐  100  200  mA  Reset pin Voltage  ‐0.5  3.3  13  V  I/O pin sink/source Current  ‐40  ‐  40  mA  Programming Code examples for TouchKey 2 click, written for MikroElektronika hardware and compilers are available on Libstock. This code snippet initializes the MCU and display, and in an endless loop recognizes which key is being pressed. The key that was touched last is shown on the display. 01 void main( void ) 02 { 03 system_init(); 04 display_init(); 05 06 TFT_Set_Font( &HandelGothic_BT21x22_Regular, CL_RED, FO_HORIZONTAL ); 07 TFT_Write_Text( "Press Any On-board Key", 50, 120 ); 08 09 while( true ) 10 { 11 // Key A has been pressed 12 if( key_A_pressed && old_key != KEY_A ) 13 { 14 display_key( "A", CL_RED ); 15 key_A_pressed = false; 16 old_key = KEY_A; 17 } 18 // Key B has been pressed 19 else if( key_B_pressed && old_key != KEY_B ) 20 { 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 } display_key( "B", CL_GREEN ); key_B_pressed = false; old_key = KEY_B; } // Key C has been pressed else if( key_C_pressed && old_key != KEY_C ) { display_key( "C", CL_BLUE ); key_C_pressed = false; old_key = KEY_C; } // Key D has been pressed else if( key_D_pressed && old_key != KEY_D ) { display_key( "D", CL_PURPLE ); key_D_pressed = false; old_key = KEY_D; } } https://shop.mikroe.com/click/hmi/touchkey-2 3/21/2017