A tiny Base64 encode/decoder library for the Arduino with minimal memory requirements.
See [https://en.wikipedia.org/wiki/Base64](Wikipedia on Base64) for details. This library aims to minimize memory consumption by encoding a given message byte by byte.
Encoding a message is done by calling Base64Coder::encode(uint8_t) consequently with all bytes of the message. After each call encode(uint8_t) you must call char Base64Coder::eget() to read the Base64 encoded symbols. Call as often as needed until it returns '\0'. For each byte put into the encoder, eget() will return one or two Base64 symbols.
After all message bytes have been encoded, call char Base64Coder::finalize() until it returns '\0'. This may yield the last Base64 symbol and will add (up to 2) neccessary padding symbols.
Decoding a string of Base64 symbols is done by calling bool Base64Coder::decode(char) consequently with all symbols of the encoded message. Base64Coder::decode(char) returns true, if enough symbols have been decoded to produce the next byte of the decoded message.
Call uint8_t Base64Coder::dget() to get the next decoded message byte.
Place the Base64Coder library folder in your <arduinosketchfolder>/libraries/ folder. You may need to create the libraries subfolder if its your first library. Restart the IDE.
To use it in your code, construct an instace of the coder with
#include <Base64Coder.h>
Base64Coder coder;Before encodung or decoding, initialize via coder.init();
See Base64Test.ino example for more details on how to encode and decode a message.