Question: Is it possible to implement water proofing in CSA?
Response: Kindly note that CSA does not support waterproofing. Waterproofing is only possible with CSD using the shield electrode.
Following are the recommendations that you may find useful to minimize false triggering caused by either fresh water raindrops or salt water with the CSD module:
1. Place the sensors vertically or at an angle to the horizontal so that water drops naturally move off of the sensor plate and large water drops do not accumulate.
2. Use a water-repellent, non-absorbent material as the front panel insulator. This minimizes water streaks and films on the device panel. This is especially important if the water is highly conductive. For example: Seawater.
3. The guard sensor is required in situations where the application may be subjected to continuous water streams. It is not required if the device is subjected to rain only.
4. The shield electrode between buttons should be at least 10 mm wide. This allows you to effectively suppress the influence of water drops.
We would suggest you to refer to the following application notes related to CapSense, which are available on our website:
AN2398 - Waterproof Capacitance Sensing
AN2292 - Layout Guidelines for PSoC Capsense
AN14459 - CapSense Device and Method Selection Guide