I might be old school .. I really liked to have a programming manual while doing bare bones development (I did this using a Analog Devices device). The HAL didn't work out of the box as I didn't understand what else was needed for it to work. I had to call certain functions. In that case it would be less work to implement the same functionality using interrupt handlers which I wrote and that would give me better understanding of the platform as I would have to read the documentation.