One important aspect of a comprehensive test strategy for an IoT product is automated testing using physical devices. Hardware-based testing comes with its own set of challenges, and this is particularly true for wireless devices. Luckily, many building blocks - great open source frameworks as well as various hardware tools - are readily available. In this presentation, Andreas and Reto share their experiences from testing a Zephyr-based implementation of a proprietary sub-GHz wireless protocol. They explain how to shield a testbed from unwanted RF interference and how to re-introduce interference deterministically, discuss a few adventures with USB, which hardware tools they found useful, and when even a really cheap tool may be sufficient in place of expensive test equipment. On the software side, the presentation discusses various useful features of Zephyr, the use of pytest for testing with physical devices, as well as some other valuable open source tools, such as GNU Radio and Scapy. While testing physical products in a noisy RF-environment can be a difficult challenge, this presentation shows how various tools and open source products help make the task a lot more accessible for everyone.