A simple kitchen timer implemented in digital logic on a Lattice MachXO2 CPLD.

(It's brighter in person.)

• Features
  • Large 7-segment display
  • Count-down/count-up timer
  • Alarm and silent modes
  • AAA battery powered
• Limitations
  • 10 hour battery life
• ICs
  • Lattice MachXO2-256 CPLD
  • SG-3030JC 32.768 kHz Oscillator
  • TLV61225 Boost Converter 1.5V -> 3.3V
• Dimensions of 80mm x 49mm
• Power consumption of ~100mA @ 1.5V (mostly from LEDs)

• README.md - this README
• teatimer.v - Verilog source
• teatimer_tb.v - Verilog test bench
• Makefile - Makefile for simulation
• hw/ - Schematic and layout
  • teatimer.sch - Eagle schematic
  • teatimer.brd - Eagle layout
  • teatimer-sch.png - Schematic image
  • teatimer-brd.png - Layout image
  • gerbers/ - Gerbers
• diamond/ - Lattice Diamond project
  • teatimer.ldf - Project file
  • teatimer.v - Symlinked Verilog source
  • teatimer.lpf - Constraints
  • teatimer.jed - JEDEC bitstream
• misc/ - Miscellaneous scripts

The design uses 67 bits of state, 91% of the LUTs for logic, and all of the I/O.

Number of registers:     67 out of   322 (21%)
   PFU registers:           63 out of   256 (25%)
   PIO registers:            4 out of    66 (6%)
Number of SLICEs:       117 out of   128 (91%)
   SLICEs as Logic/ROM:    117 out of   128 (91%)
   SLICEs as RAM:            0 out of    96 (0%)
   SLICEs as Carry:         27 out of   128 (21%)
Number of LUT4s:        232 out of   256 (91%)
   Number used as logic LUTs:        178
   Number used as distributed RAM:     0
   Number used as ripple logic:       54
   Number used as shift registers:     0
Number of PIO sites used: 18 + 4(JTAG) out of 22 (100%)
Number of block RAMs:  0 out of 0
Number of GSRs:  1 out of 1 (100%)

• U1, Lattice MachXO2 CPLD, LCMXO2-256HC-4SG32C - family datasheet
• U2, 32.768 kHz Oscillator, SG-3030JC32.7680KB:ROHS - datasheet
• U3, Boost Converter, TLV61225DCKR - datasheet
• DISP1, 7-segment Display, HDSP-B03E - datasheet
• SP1, 4kHz Buzzer, PKM13EPYH4000-A0 - datasheet

Price breaks based on quantities to build 10 units. All prices in US dollars.

• Silent mode is not 100% silent (design oversight)
• Limited battery life (~10 hours)

• v1 - 01/30/2017
  • Initial release

• v0.1.0 - 01/30/2017
  • Initial release

teatimer is CC-BY-4.0 licensed. See the included LICENSE file.