xprintf

http://elm-chan.org/fsw/strf/xprintf.html

xprintf is a compact string I/O library. It is ideal for tiny microcontrollers that has insufficient program memory for regular printf function. The recommended use is: writing formatted strings into LCD or UART and for debug/maintenance console.

xprintf can be configured with configuration options to reduce the module size. Following table shows the example of code size in Cortex-M3 (gcc -Os). long long and float want C99 or later.