So there is a follow up project: #reDOT_Matrix !
Please like/follow that project to get updates and support me for the HAD-Prize 2018!
In that new Project I will put multiple 5x7 Matrixes on the same PCB an controlled by one MCU. I was thinking that there is no use case for me for one digit display and "wasting" one MCU per digit seemed not perfect for me. (although the STM8 is super cheap)