Cypress CY3270 Manuel D’Utilisation

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CY3270 PSoC® FirstTouch™ Guide, Document # 001-15945 Rev. **

Getting Started

2.4.4

CapSense Proximity Sensing Demonstration

The CapSense proximity sensing demonstration shows how to use a proximity sensor to control
LED color. 

The proximity detector requires the use of a Proximity Antenna and can sense an object with approx-
imately 2–3 inches of range. In the FirstTouch Kit, this sense antenna is formed by attaching the pro-
vided wire into the pin socket labeled PRX1 as shown in 

. Note Upon power up,

the FTMF will establish a baseline reading of the Proximity Antenna. It is therefore necessary to con-
nect the Proximity Antenna prior to plugging in the FirstTouch kit.

The project is setup to recalculate this baseline approximately every 30 seconds. Also notice how
the shape and position of the wire affects the demonstration operation and the proximity sensing dis-
tance.

Figure 2-5.  CapSense Proximity Sensing Demo Schematic

Follow the CapSense Touch Sensing based guidelines in section 

 to simulate, build, and program the FTMF Expansion Board with the

CapSense proximity sensing demonstration. Slowly approach the CapSense proximity sensor
(depicted in 

) with your fingers and notice how the color of the LED color

changes. Removing your fingers leads to the LED color slowly reverting back to its initial state. The
CY8C21434 PSoC that resides on the FTMF Expansion Card detects the relative proximity of your
fingers to the FTMF Expansion Card and controls the LEDs output.