I designed this clock because i had a few unused analog ammeters with percentage scale and i was thinking it would be interesting to use them for displaying the time. This clock is based on Microchip's PIC16LF19175 which features a battery backed RTC to keep the time and date.
The clock is equipped with a very simple IR proximity sensor for activating the LEDs by hand. LEDs are turned off after 10 seconds to save the battery. Analog meter is driven by current source composed of DAC MCP4911, as a source of control voltage, and OPAMP MCP6031. The analog meter gradually displays percentage of day, week, month and year. Currently displayed percentage is indicated by two LEDs on the left side of pcb.
The clock is powered by a single AA cell but its voltage needs to be increased because 1.5V is too low for driving the LEDs. This is done by boost converter MCP16251 which generates 3.3V.
The battery run-time is approx. 6 weeks assuming the LEDs are activated only few times a day.