Skip to content

A 4-digit 7-segment digital clock, based on the inexpensive Padauk microcontrollers

License

Notifications You must be signed in to change notification settings

serisman/pdk-digital-clock

Folders and files

NameName
Last commit message
Last commit date

Latest commit

 

History

20 Commits
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Repository files navigation

pdk-digital-clock

A 4-digit 7-segment digital clock, based on the inexpensive 8-bit Padauk microcontrollers

Links

This uses the SLR0394DRC5BD 4-digit 7-segment common cathode 'time' display, which sits over the top of the 74HC595 and the (2) 4x resistor packs. The 74HC595 is used to drive the (4) 7-segment digits, (2) outputs per digit for extra current sink capabilities. The segments themselves are driven directly by the Port B outputs of the Padauk microcontroller.

A single push button is used to set the time, with the following 'user interface':

  • A short press will temporarily show the current 'seconds'.
  • A medium-press will switch to time config mode. While in config mode:
    • A short press will increment the currently selected time value, with rollover.
    • A medium-press will switch to the next time value, or exit config mode if on the last time value.
    • A long-press will exit config mode.

This digital clock is powered via micro USB cable, although it should work at much lower voltages as well. It isn't really suitable for long-term battery operation, as the LED based 7-segment display consumes enough energy that it wouldn't last very long.

Power Consumption (displaying 12:00)

  • @ 5.0V = ~19mA
  • @ 4.5V = ~16mA
  • @ 4.0V = ~13mA
  • @ 3.5V = ~10mA
  • @ 3.0V = ~7mA
  • @ 2.5V = ~4mA
  • @ 2.0V = ~1mA

Schematic

(for 16-pin PFS154, PFS173, PMS152, or PMS154C)

Schematic

Compatibility

This project is currently intended to be run (without modifications) on the PFS154, PFS173, PMS152, and PMS154C Padauk microcontrollers, but it should be able to be modified to run on other 16-pin Padauk microcontrollers that are supported by SDCC and the Easy PDK Programmer.

Bill of Materials

Ref Part # Description Footprint Purchase Link Price Minimum Purchase
PCB - - - OSHPARK $1.033 each $3.10 for 3
U3 SLR0394DRA5BD 4-digit time-mode 7-segment display - LCSC C225902 $0.501 each $0.501 for 1
U1 PMS152-S16 8-bit Padauk microcontroller SOP-16 LCSC C317590 $0.077 each $0.39 for 5
U2 74HC595D Serial shift register SOP-16 LCSC C93838 $0.046 each $0.46 for 10
Y1 - 32.767KHz radial cylinder crystal 2x6mm LCSC C2236 $0.045 each $0.45 for 10
J1 - Micro USB connector - LCSC C393940 $0.026 each $0.52 for 20
SW1 TS24CA SPST side-actuated button tactile switch - LCSC C393942 $0.025 each $0.50 for 20
C2 - 10uF capacitor 0805 LCSC C92786 $0.015 each $0.73 for 50
C3,C4 - 20pF capacitor 0805 LCSC C309037 $0.007 each $0.36 for 50
RN1,RN2 - 4x 680 ohm resistor network 0603_x4 LCSC C102679 $0.007 each $0.35 for 50
C1 - 100nF capacitor 0805 LCSC C235732 $0.006 each $0.30 for 50

Total: ~$1.80 each (+/- depending on quantity)

Images

Front (without 7-segment display) Back Installed and working!

Copyright and License:

About

A 4-digit 7-segment digital clock, based on the inexpensive Padauk microcontrollers

Topics

Resources

License

Stars

Watchers

Forks

Releases

No releases published

Packages

No packages published