Spectrometers play a decisive role in the education of A-level and/or under-graduate students in the field of natural sciences. They are capable to demonstrate atomic emission, transmission, reflection and fluorescence spectra, but can be used for wavelength filtering, as well. Here, we present a do-it-yourself spectrometer setup based on a Czerny--Turner design that (a) can be used for all measurement types with one and the same setup and (b) is capable to spectrally resolve atomic emission lines. We use LEGO® bricks for the optomechanical construction and combine it with affordable, but high-quality optical components and linear array based on a charge-coupled device (CCD). A modular design is implemented and allows for a quick change between the various measurement techniques, but also fosters the technological understanding of the underlying systems' optical design.