Cypress CY3270 manual CapSense Proximity Sensing Demonstration

Getting Started

2.4.4CapSense 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 Figure 2-1 on page 8. 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 2.5 Exploring the FTMF Expansion Card Demonstration Projects to simulate, build, and program the FTMF Expansion Board with the CapSense proximity sensing demonstration. Slowly approach the CapSense proximity sensor (depicted in Figure 2-1 on page 8) 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.

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