Research related to photovoltaic panels comprises different topics starting with modelling solar cells, finding new maximum power point tracking (MPPT) algorithms, testing existing ones or designing of DC/DC converters for MPPT systems and microgrids that incorporate photovoltaic energy sources. In each of the examples above a deep knowledge of photovoltaic panels is required, as well as a reliable measurement system that can deliver continuous, stable light with enough power to meet standard test conditions (STC) and that can ensure repeatable results. Therefore this paper presents a low-cost solar simulator with a microcontroller-based measurement system, that can be used for various measurements of low-power photovoltaic panels.