Adjustable Touch Button

Adjustable Touch Button is a compact and versatile touch-sensitive button designed for easy integration and connectivity. Whether you need multiple touch inputs or a seamless mounting solution, this button simplifies the process. The idea originated from a real-world challenge—when implementing 12 touch buttons into a device, I realized that traditional options require separate wiring for each button, resulting in complex and bulky connections. This project aims to solve that problem by offering a more efficient and streamlined design

Advantages of the Adjustable Touch Button

• Easy integration - Thanks to the I2C bus, it can be seamlessly connected to various platforms such as Arduino, ESP32, and STM32.
• Support for TTL levels of 5V and 3.3V – Ensures smooth integration with modern electronic platforms.
• Efficient wiring – Allows parallel connection of up to 16 buttons using only a 6-wire cable.

• Simple cable assembly – With Micromatch connectors, cables can be easily created by crimping the connector directly at the desired location.
• RGB LED backlighting – Each button is equipped with a WS2812 RGB LED, allowing color and intensity customization via the I2C bus.
• High sensitivity – The button responds even through 8mm thick plexiglass.

• Adjustable sensitivity levels – Offers four sensitivity settings: 1mm, 2mm, 4mm, and 8mm, which can be configured via the I2C bus.
• Dual interrupt pins – Enables use both with a microcontroller and as a standalone component.
• Adjustable I2C address – Ensures flexible configuration via the I2C bus within the range of 1–127.
• Button status detection – Accessible via both the I2C bus and the interrupt pin INT1 for versatile monitoring
• Persistent settings – All configurations are stored in internal memory, requiring setup only once.

Pinout of the Output Connector

• 1. INT1 – Open-collector output, activated when the button is pressed and deactivated when released.
• 2. SCL – I2C clock signal, open-collector output.
• 3. GND – Ground.
• 4. SDA – I2C data line, open-collector input/output.
• 5. VCC – Power supply, protected by a 500mA fuse.
• 6. INT2 – Open-collector output, activated when the button is pressed and remains active until the button state is read via the I2C bus. Once the state is read, it deactivates.

I2C Commands and Responses

• SET TOUCH COLOR

         Command: 0xC1
         Data: R (0-255), G (0-255), B (0-255), Intensity (0-100)
         Receive String: "OK\r", "UNK\r", "ERR\r", "OVF\r", "WAI\r"
  

• SET NOTOUCH COLOR

         Command: 0xC2
         Data: R (0-255), G (0-255), B (0-255), Intensity (0-100)
         Receive String: "OK\r", "UNK\r", "ERR\r", "OVF\r", "WAI\r"
  

• Sensitivity

         Command: 0xC3
         Data: Sensitivity Level (1-4)
         Receive String: "OK\r", "UNK\r", "ERR\r", "OVF\r", "WAI\r"
  

• Change I2C Address

         Command: 0xC4
         Data: I2C Address (1-127)
         Receive String: "OK\r", "UNK\r", "ERR\r", "OVF\r", "WAI\r"
  

• Enable Interrupt Pin

         Command: 0xC5
         Data: 1 – Disable, 2 – Enable
         Receive String: "OK\r", "UNK\r", "ERR\r", "OVF\r", "WAI\r"
  

• BTN Status

         Command: 0xC6
         Data: (not sent)
         Receive Value: 0xAA – Button Pressed,0xBB – No Press
         Receive String: "UNK\r", "ERR\r", "OVF\r", "WAI\r"
  

Technical Specifications

• Supply voltage and current: 3.3–5VDC, max. 60mA
• I2C communication: Max speed 100kHz, bus length up to 1 meter
• Maximum current on SCL/SDA pins: 20mA
• Maximum current on INT1/INT2 pins: 20mA
• Maximum panel thickness: 8mm (tested materials: glass, plexiglass)
• LED Luminance: Red – max. 550mcd, Green – max. 1100mcd, Blue – max. 200mcd
• Dimensions: 22mm × 18mm