Dragino DS03A-NB-GE NB-IoT Türsensor Sonde and they can be purchased

and they can be purchased fully assembled or as partial kits:

removing the need for processor-intensive software PWM

downloadable Windows installer for full featured and open source tools as alternative to the commercial ARM development packages: GCC C compiler

Der LV-MaxSonar-EZ4 ist der schmalste Strahlbreitensensor in der LV-MaxSonar-EZ-Sensorlinie

Dragino DS03A-NB-GE NB-IoT Türsensor Sonde and they can be purchasedThe Dragino DS03A NB GE is an NB IoT based door sensor for IoT applications. It reliably detects door opening and closing states and transmits the data to an IoT server via the NB IoT network. Users can monitor the current door status, opening duration, and opening cycles. Features: Connectivity: NB IoT Door opening closing detection Door opening closing statistics Datalog function, open alarm function Bluetooth (BLE) configuration Wireless OTA