As an increasing number of people rely on Wi-Fi connectivity for communication, collaboration and productivity, the more important it becomes to be able to quickly detect and resolve Wi-Fi related issues. An effective way of doing this is simulating end-user clients by setting up monitoring probes in Wi-Fi enabled locations, but existing solutions can quickly become prohibitively expensive and make organizations reliant on external providers. We propose an innovative, open system based on commonplace Raspberry Pis (RPis) requiring minimal infrastructure, making it easy to add and administer probes in a cheap, self-sufficient manner. The system mainly consists of two parts: the central web server used for administering probes, and the customized Linux distribution running on the probes. To add probes, users register some info about their RPis in a web interface and load them with a custom image provided by the site. Through an automatic update process with the server - initiated by the RPis when booted - the RPis will essentially be converted to probes. They can then be moved to desired locations where they will continuously perform measurements and send data to specified databases. Additional probes can easily be added at a later time, and configurations for existing probes can be updated effortlessly. An example of a system use case is an NREN setting up the central server and database, for instance Elasticsearch with Kibana for visualizations like UNINETT has done. System administrators for national institutions like universities can then be the users of the system, allowing them to easily register probes and see measurement results, using the NREN's infrastructure. Through creative use of Raspberry Pis and simple Wi-Fi adapters hardware costs remain low, and the software used is open-source and free to use. Altogether, the system will allow more NRENs and campuses to perform Wi-Fi monitoring on their premises, benefiting from the advantages it brings.