ramon here with a small update again
just wanting to state the performance increase per watt in floating point math (for alpha blending/antialias) between the original design (teensy 3.2) and the new design (stm32l4)
first i'd like to point that the stm32l4 is at least 3x as power efficient as the teensy 3.2 spec wise
in reality more like 4x as the teensy 3.2 requires a seperate bootloader ic which used power too.
then the floating point math.... the teensy 3.2 doesn't have a fpu at all, so calculations are slow for sure, on the stm32l4 however, the speed is over 7x compared to the teensy, as the stm has a fpu.
compared to power effifiency, this is about a factor 28 or so (fpu math / watt)
also, might change from the stm32l476 to the stm32l496 with 320k of sram in the future, for bigger apps, and it's more power efficient too. (91micro amps / mhz versus 100 micro amps / mhz)