I noticed in bitcoin when using the tiny-secp256k1 library to sign the signature for a signature hash of an input, the signature is always the same. However in other ECDSA secp256k1 libraries (im using one by nordic semi conductors) the signature is always different.
Am I misunderstanding something? is there a difference in the signature algorithms? I read something about randomly and deterministically calculating the k value, should it matter if it is random or not? or is there possibly extra encoding done after the signature hash is signed in bitcoin secp256k1?