Touch Pad compatible Microcontroller – Future Microcontrollers


The Microcontroller IC is a top famous device, which yields its application in almost all areas.  The recent advancement with microcontroller had reached the sky today. To make it more advanced and user-friendly, one of the leading Microcontroller Company, STMicroelectronics has introduced the STM8 Microcontroller which has a compatible feature of Touch Sensor software library. This can support user interfaces with capacitive buttons and also works with software for capacitive sensing.

The main two IC’s of this category are: STM8S105 and STM8S207. The STM8S105 can support Access Line with 16MHz CPU frequency and up to 32 Kbyte Flash, and the STM8S207 Performance Line operates at 24MHz and up to 128 Kbyte Flash. The iC can be interfaced with CAN2.0B interface, two U(S)ARTs, an I2C and SPI ports.

Touch controls improve the look and feel of end products such as MP3 players, televisions, domestic appliances, or printers, compared to mechanical switches or membrane keypads. As he touch controls have no moving parts, it reduces the materials costs and enhances the reliability.

ST’s touch-sensing software library transforms any 8-bit STM8 MCU into a capacitive touch-key controller. It helps for the designers to combine touch sensing functions through multiple configurations, such as touch keys, wheels or sliders. It can also help for communication, LED control, beeper, and LCD control.

The touch panel includes a RC network which is formed by a single resistor and the touch electrode capacitance. On monitoring the charge and the discharge timing cycle of this RC network, the human touch is sensed. The IC can also support 24 individual touch pads. The memory consumption by the touch sensing library is also very low, which helps the designer to include variety of accessories through the ports.

An embedded automatic calibration software layer saves final adjustment during manufacturing and enables faster time to market. To maximize long-term reliability the library contains an Environmental Change System (ECS). The ECS compensates for natural fluctuations in operating voltage and capacitance as well as environmental effects such as temperature and humidity.

STMicroelectronics is expected at the second quarter of 2009 and it is planned to integrate a touch-sensitive evaluation board along with it.

Features of STM8:

  • 130nm embedded non-volatile memory
  • Touch channel cost is very low
  • Supports 24 Touchpads
  • Less cost
  • Flash memory
  • Safety to work
  • 8 bit architecture
  • Compatible with 8 bit and 16 bit applications
  • Low Noise

Note: The IC picture is not related with the IC manufacturers.It is designed by the author for readers understanding.

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