I'm looking for the schematics of a device for showing active wireless radio transmissions (GSM/UMTS/LTE and WLAN/Bluetooth) via a simple LED or beeper.
The desired field of application would be this:
When held to your smart-phone the device should blink if there is a transmission that is whenever the phone is not into airplane-mode.
Using a potentiometer one should be able to control the sensitiveness allowing the use in another scenario:
Walking around in "nowhere land" the device should flash the LED when there is a signal.
I have built similar devices for detecting power conducts in walls. Here we would have to deal with different wavelengths however. The broad range of those different wavelengths is certainly making this task more difficult.
Have you seen schematics for such a (simple) device?
Thank you very much for your help!
The desired field of application would be this:
When held to your smart-phone the device should blink if there is a transmission that is whenever the phone is not into airplane-mode.
Using a potentiometer one should be able to control the sensitiveness allowing the use in another scenario:
Walking around in "nowhere land" the device should flash the LED when there is a signal.
I have built similar devices for detecting power conducts in walls. Here we would have to deal with different wavelengths however. The broad range of those different wavelengths is certainly making this task more difficult.
Have you seen schematics for such a (simple) device?
Thank you very much for your help!