tzclock-rs

A learning exercise in embedded Rust to produce a digital clock showing five time zones.

Design

• STM32F103C8T6 MCU ("Blue Pill")
• 5 x TM1637 4 digit 7-segment displays
• 24 pulse rotary encoder with push button
• 10k linear potentiometer

Function

UTC is used as the reference time, each display is assigned an offset from this time.

The potentiometer controls the brightness of the 7-segment displays.

The rotary encoder's push button cycles through the following modes:

• normal
  • Time is shown on all displays
  • Dial has no effect
• set_hours
  • UTC time is shown on display 0 and
  • Dial adjusts hours
• set_minutes
  • UTC time is shown on display 0
  • Dial adjusts minutes
• set_offset_0
  • Each offset is shown on all displays
  • Display 0 flashes
  • Dial adjusts offset of display 0
• set_offset_1
  • Each offset is shown on all displays
  • Display 1 flashes
  • Dial adjusts offset of display 1
• set_offset_2
  • Each offset is shown on all displays
  • Display 2 flashes
  • Dial adjusts offset of display 2
• set_offset_3
  • Each offset is shown on all displays
  • Display 3 flashes
  • Dial adjusts offset of display 3
• set_offset_4
  • Each offset is shown on all displays
  • Display 4 flashes
  • Dial adjusts offset of display 4