Development of a Novel Microcontroller-based data logger

This paper describes the design and development of a microcontroller-based dual function, 1-bit digital data logger. The main function of the system is to sense TTL logic level transitions on a designated data logging input of a PIC 16F628A microcontroller from MicrochipTM, and store the resulting logic state either as an ASCII 1 for a 5 volt d.c. input or an ASCII 0 for a zero volt input; together with a time/date stamp, also in ASCII format, of when the transition occurs. The time/date stamp requirement necessitated the development and addition of real-time clock/calendar functionality to the system, complete with three types of alarms (once only, once every day, and once every week). The alarm clock/calendar forms the data logger's auxiliary everyday function, thereby making the data logger always useful. This is considered by the author to be somewhat a novelty. The ever-prevailing issues of energy efficiency, size, weight, cost, and durability in remote data logging applications motivated this research, which has resulted in a data logger that owes virtually all its functions to the microcontroller through the use of proficiently developed firmware; thereby providing a low component count, which positively addresses the aforesaid issues to a large extent.