Quantity   Component name
1 × SR04 Ultrasonic meter. 2 Euro You can by five on Amazon for 10 Euro
1 × ESP32 USB breakout. 6.3 Euto You can buy three on Amazon for 19 Euro https://www.amazon.it/XTVTX-ESP-WROOM-32-Bluetooth-Sviluppo-Compatibile/dp/B093GQGJCV/ref=sr_1_16?__mk_it_IT=%C3%85M%C3%85%C5%BD%C3%95%C3%91&crid=1BM6GFIBD3592&keywords=esp32&qid=1650659809&s=gift-cards&sprefix=esp32%2Cgift-cards%2C65&sr=1-16
1 × Relay board. 1.6 Euro Five for 8 Euro on Amazon
1 × 2 LIPO 3.7 V 1100 mAh batteries. 19.5 Euros 4 for 29 Euro on https://www.amazon.it/Batteria-ricaricabile-protezione-isolante-sviluppo/dp/B087LTZW61/ref=sr_1_8?keywords=lipo+battery&qid=1650660140&sr=8-8
1 × SIM800L breakout board. 10 Euro https://www.amazon.it/AZDelivery-Modulo-Antenna-Arduino-SIM800L/dp/B07D361WZV/ref=sr_1_7?__mk_it_IT=%C3%85M%C3%85%C5%BD%C3%95%C3%91&crid=2YAZBYOII2M2S&keywords=sim800l&qid=1650695566&sprefix=sim800l%2Caps%2C82&sr=8-7&th=1
1 × MT3608 DC-DC step up. 1.4 Euro https://www.amazon.it/ARCELI-regolabile-Switching-Converter-alimentazione/dp/B07MY3NZ18/ref=sr_1_6?__mk_it_IT=%C3%85M%C3%85%C5%BD%C3%95%C3%91&crid=3SO40IDE0LHG7&keywords=mt3608&qid=1650695753&sprefix=mt3608%2Caps%2C70&sr=8-6