Overview
The FDC2214 proximity and capacitive touch button board demonstrates the use of TI’s capacitive
sensing technology to sense and measure the presence of various objects. The board is a complete
hardware and firmware solution that integrates the FDC2214, MSP430FR5969, and TPS61029 into one
design. The firmware included processes the data from one proximity sensor and two capacitive touch
buttons via the FDC2214 to determine whether an object is in the intended sensing area. All of the
processing is done on the MSP430 allowing the board to be a standalone system. Dedicated colored
LEDs light up once the device detects a target in close proximity to the board or detects a press on the
buttons. The board is designed to operate with one AA-battery. The maximum sensing distance that can
be reliably achieved with the board is 10 cm (4 inches) as a floating system and 50 cm (19.6 inches) as a
grounded system. The cap touch buttons and firmware have been optimized to be very responsive to
quick user touch interactions
The hardware uses the 4-channel FDC2214 to multiplex through each of the three capacitive sensors: one
proximity sensor and two capacitive touch buttons. As the firmware in the MSP430 detects a user
approaching the board, a green LED lights up to indicate that an object has been detected. If the user
touches Button1, Button2, or both of them simultaneously, their corresponding red LED lights up. The
board integrates the FDC2214, MSP430FR5969 and the TPS61029 as a complete standalone system.
Figure 1 shows the top side of the reference design.
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