Introduction: Tix Clock Gems

Tix Clock Gems

This TIX clock implementation is a great first time project for beginners. Apart from visually pleasing, the clock is of practical use and keeps accurate time via it's 32Khz clock crystal. The construction is easy as there are only 4 breadboard wires involved.

At the same time it allows certain creativity in that 1) LEDs within the same group can be re-allocated for different patterns, and 2) the length of individual LEDs can vary as to different a personalized LED gem "landscape".

The TCG (Tix Clock Gems) demonstrates LED charliplexing in groups and usages of timers.

Time Telling

Tix Clock Gems works as a Tix clock, in that you tell time by counting the number of LEDs. For my layout, one single blue LED on top left of the constructindicates 10th of an hour. The top right group of green LEDs shows the hours (2nd digit).

The minutes are show at the bottom of the construct, the amber LEDs are the 10ths of minutes and the red LEDs represent the one's.

For 11:32, you will find a blue LED and one green LED lighted up for 11th hour, and 3 amber plus 2 red LEDs will indicate it's the 32nd minute.

The LEDs will altenate every second when possible. TCG will be put to sleep after 10 seconds.


  • Minimal jumper wires, 4 on a mini breadboard
  • Personalization via LED placements and leg lengths
  • Battery operated from 3V
  • Use of 32Khz clock crystal to keep time, power-down sleep mode (LPM3) takes less than 1uA power

Application Notes

  • Single button press shows time for a few seconds, TCG returns to sleep after that
  • Long press setup time, starting with the hours, related LEDs starts to blink
  • Short press advance the hour value. Another Long press confirms the entry
  • The tenths of the minutes and the minutes are subsequently entered like the hour
  • Once the hours and minutes (tenths and singles) have been entered, TCG returns to show mode

Step 1: ​Get Parts

All parts can be acquire from Ebay at very low price.

  • 170 tie point mini breadboard
  • MSP430G2412 (or other G/F series dip 20 pin devices w/ 4k flash)
  • Lots of LEDs (1 blue, 9 green, 6 yellow, 9 red)
  • Tactile button
  • 32Khz clock crystal
  • CR2032 button cell holder and battery

Step 2: Breadboard Layout and Assemblying


  • Follow breadboard layout and place jumper wire on mini breadboard
  • Place MSP430G2412 on breadboard
  • Place Tactile Buttons
  • Cut your LEDs into different lengths, *be sure to maintain one leg longer
  • Place LEDs in groups of (1..9), opposing pairs on the same pin can be swapped for effect. Ex at b0-b1 #3 and #8 can be swapped. The "+>" is the blue LED indicating 10+ hours
  • Place Battery Holder


Source code can be found here in my github repository. You will need a TI MSP430G2 Launchpad to program the MCU.

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Time Contest

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Time Contest