This small realization, based on one of the most common IC MAX232 is designed to create a small and convenient TTL to RS232 and vice versa convertor.
In many cases can be very handy to be able to convert 1.5V to 5V. Then you can power microcontroller or LED from a single AA or AAA battery. It is simple to do this as there are special ICs as MAXIM MAX1674 or MAX7176.
