Rapberry 3 has a few models, and a difference in hardware is crucial.

512 MiB RAM is really tough. An operating system uses the memory on its own, let's say 128 MiB. Also you need some memory for a disk cache and whatever the OS periodically does in background, let's say plus 128 MiB. Perhaps you'll want to add I2P and/or Tor on top of that.

With 1 GiB RAM, you can run Blacknet node and use it for solo staking... until we implement a hardfork with zero-knowledge proofs, then it's too likely to not fit too.