The USB keypad reference design demonstrates crystal free USB operation. Microchip has partnered with Lumvatech to demonstrate a low-cost aesthetic design, with touch capability and LED lighting integrated. All features are driven with a single PIC16F1459 MCU.
USB is one of the most common serial interfaces used in a wide variety of applications. The USB 2.0 module with clock recovery from USB host, eliminates the need of an external crystal and thereby saving BOM costs and space on designs. The PIC16F145X family and PIC18FXXK50 families feature Active Clock Tuning which guarantees 0.25% accurate 48Mhz internal oscillator across all temperature range when connected to USB host.
This design also features the integration of 18 touch buttons based on the Capacitive Voltage Divider (CVD) technique from Microchip. A matrix-based approach is followed where of the 9 ADC channels available, five are used for row detection and four for column detection. Two columns are also used for proximity detection. LED backlight for the keypad with auto power off and audio feedback using the piezo buzzer is also implemented.
The USB keypad reference design demonstrates crystal free USB operation. Microchip has partnered with Lumvatech to demonstrate a low-cost aesthetic design, with touch capability and LED lighting integrated. All features are driven with a single PIC16F1459 MCU.
USB is one of the most common serial interfaces used in a wide variety of applications. The USB 2.0 module with clock recovery from USB host, eliminates the need of an external crystal and thereby saving BOM costs and space on designs. The PIC16F145X family and PIC18FXXK50 families feature Active Clock Tuning which guarantees 0.25% accurate 48Mhz internal oscillator across all temperature range when connected to USB host.
Demonstration Highlights
■ All features driven by a single device – PIC16F1459
■ Crystal-free USB operation
■ 18 touch buttons and proximity detection using
CVD technique
■ LED backlight with auto power off
■ Audio feedback using the piezo buzzer
■ USB HID interface
■ Plug and play
■ Low-cost lightweight design
■ Integration of USB and mTouch framework from MLA
Read more: USB Keypad Demonstration – Crystal Free USB and mTouch™ Sensing Solutions