Real-time Clocks: LED Displays

This lecture covers the use of mechanical and electronic time bases in watches, focusing on the stability of oscillators and the division of time units using gears. It also discusses the use of quartz oscillators in electronic watches, with a frequency of 32'768 Hz and dividers to obtain a 1 Hz signal. The lecture further explores power supply considerations, including the use of lithium batteries and supercapacitors. Programming techniques for microcontrollers with a 32 kHz quartz are presented, emphasizing the importance of maximizing sleep mode. Specialized integrated circuits for real-time clocks, such as DS1307 and PCF8523, are introduced. The lecture concludes with an overview of internal real-time clock features in some microcontrollers.