I use Aeotec Z-Wave Multisensors permanently connected to USB power (they can also run on battery). However, any PIR motion sensor would work, such as the cheap

I use Aeotec Z-Wave Multisensors permanently connected to USB power (they can also run on battery). However, any PIR motion sensor would work, such as the cheap models from Xiaomi (but there's the extra cost of battery changes).