CY8CKIT-003A Cypress Semiconductor Corp, CY8CKIT-003A Datasheet - Page 29

• Manufacturer Part Number: CY8CKIT-003A
• Description: KIT DEV PSOC3 FIRSTTOUCH STARTER
• Manufacturer: Cypress Semiconductor Corp
• Series: PSoC® 3 FirstTouch™r
• Type: MCUr

Specifications of CY8CKIT-003A

• Contents: Board, Battery, Cable, CD, Documentation, Wire
• Lead Free Status / Rohs Status: Lead free by exemption / RoHS compliant by exemption
• For Use With/related Products: PSoC® 3
• Other names: 428-3113

4.5.1
CY8CKIT-003 PSoC 3 FirstTouch Starter Kit Guide, Spec. # 001-49613 Rev. *B
How the Proximity Sensor Project Works
Proximity detection is performed by a proximity antenna acting as a capacitive sensor. The proximity
antenna consists of a wire connected to the proximity connector on the board.
Upon power up, the board establishes a baseline capacitance value of the board along with the
antenna attached to it. This is used as a reference value of capacitance and is called the parasitic
capacitance of the board.
When a conductive object such as a human finger is brought close to the antenna, the overall
capacitance of the board changes. This change in capacitance determines the proximity of the finger
to the antenna. An increase in capacitance corresponds to the finger being closer to the antenna.
This is used to light up the LEDs based on the proximity of the finger to the antenna. The number of
LEDs turned on increases as the proximity of the finger increases.
To establish the parasitic capacitance, the antenna must be connected to the board before power up.
The baseline for capacitive sensors is updated continuously by the firmware. This accounts for any
changes in environmental conditions during the operation.
Figure 4-18. Proximity Sensor Project Flowchart
Scan the Proximity sensor
update LED display
Read signal value
Is sensor active?
Boot
Start
Yes
No
Example Projects
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