I've reached some conclusions about the component responsible for generating the spectrogram. It doesn't seem difficult to implement, although it requires a good command of TouchGFX. At the moment, I don't yet have the necessary knowledge to develop it on my own. I believe that guidance from someone experienced in creating custom components would make the path shorter and more objective. I already have some implementation ideas, but I need to validate the approach before moving forward.
My proposal is based on a multidimensional matrix where, in addition to the time index, I store the frequencies present and the magnitude corresponding to each one. Considering an interval of 0 to 3 seconds (for example, 3000 ms), I can fragment the time into smaller windows—such as 20 ms—depending on the characteristics of the microphone used, in this case the STM32N6570-DK. Each time index of the matrix would represent a frame containing multiple frequencies detected at that instant, along with their magnitudes. It's important to highlight that there isn't just one frequency per instant, but potentially hundreds or thousands within the 0 to 1 kHz range. These frequencies could be grouped into bands, for example, 30 Hz or 60 Hz, forming the Y-axis of the spectrogram.
The challenge lies in the graphical representation, as the available display is approximately 800x480 pixels, which limits the effective vertical resolution after discounting labels and markers. I would need to compress the frequency bands to something between 100 and 400 pixels in height. Each pixel would represent an interpolation of the magnitude of that band, probably using a color gradient to improve visualization, since a single isolated pixel would have little visual expressiveness. I am still refining the model of this matrix, which would basically give me access to tuples of the type (time, frequency, magnitude), and the component would draw the graph from that. I searched the manuals for some reference or example close to this type of implementation, but I haven't yet found anything that directly solves this need.
