Capacitive wake-up

[Stinde]

Is it possible to use ST25R3916 capacitive wake-up outdoors? The reading area can be wet, frozen or snow covered.

[Travis Palmer · Accepted solution]

Hello Stinde,

When the reader is mounted outdoor using a propper housing there should be no problem for that.

For both, capacitive and inductive wake-up apply the same rule:

If the environment changes ( = temperature, metal in close proximity, moisture (mainly influencing capacitive wake-up),..) then the reader will wake-up.

You can then either use automatic averaging which helps filtering those effects or just re-arm the wake-up if no tag has been found.

br Travis

[Stinde]

Hi Travis,

I was thinking since capacitive wake-up is sensing water in human hand. If there is a layer of water between the sensor and hand, can the capacitive sensor really detect the hand behind the water layer. I know the averaging can help in slowly changing environment, but is the water layer close to sensor plates acting as a short circuit for electric field?

Best Regards,

Stinde