Assuming jstefanop et. al. get it running on the Orange Pi Zero, the biggest limitation is the storage space; my node is currently using 24G to store the blockchain, so you'll need a sizable SD card.
It could be more practical to store the blockchain on some USB flash stick since there's an USB port available anyway. That way the SD card size wouldn't matter that much and updating the firmware by fully erasing the card content wouldn't reset the blockchain back to zero (or to some other older snapshot the firmware possibly provides).