Unexpeced approaching behind when riding frightened me sometimes, although ready made products are in the market, I made bicycle radar demo. Limitations LD2410 covers 4~5m, so it can miss fast ...

MQTT gateway for ESP8266 or ESP32 with bidirectional 433mhz/315mhz/868mhz, Infrared communications, BLE, Bluetooth, beacons detection, mi flora, mi jia, LYWSD02, LYWSD03MMC, Mi Scale, TPMS, BBQ ...