string to hex string /hex string to string conversion

That code is like decoding a puzzle! I saw the 256 + bit and I'm thinking What!! Then I twigged that it is to ensure there's at least two hex chars. Thanks for the tips.

Unfortunately the Quectel BC95 uses hex ascii. Why? Who knows. I can't think of any other AT module that does it that way.

We were having some memory problems especially when receiving, so I had thought my code was not too efficient. I had it in my mind that there might be a simple way to use a byte array and cast it to a string. That way there's no copy and allocate.