README.md
teatimer

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

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(It's brighter in person.)

Details


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)


Project Structure


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


Design Summary

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%)


Datasheets


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


Schematic



Layout



Bill of Materials




  
Qty
  
Part
  
Refdes
  
Digi-key Part Number
  
Total Price




  
1
  
Lattice MachXO2-256 CPLD
  
U1
  
220-2636-ND
  
2.830


  
1
  
Oscillator 32.768kHz
  
U2
  
SG-3030JC32.7680KB:ROHS-ND
  
1.398


  
1
  
TLV61225 Boost Converter
  
U3
  
296-36756-1-ND
  
0.775


  
1
  
NPN BJT (Buzzer Driver)
  
Q1
  
BC817-40LT1GOSCT-ND
  
0.103


  
1
  
PMOS FET (Polarity Prot.)
  
Q2
  
SI2365EDS-T1-GE3CT-ND
  
0.297


  
4
  
Tactile Switch (Buttons)
  
SW1-SW4
  
CKN9085CT-ND
  
0.776


  
1
  
Slide Switch (Power)
  
SW5
  
CKN9558-ND
  
0.648


  
1
  
7-segment LED Display
  
DISP1
  
516-2745-ND
  
2.821


  
1
  
Buzzer 4kHz
  
SP1
  
490-4698-ND
  
0.499


  
1
  
Battery Connector AAA
  
J1
  
36-2466-ND
  
0.928


  
1
  
SMD Header 1x6
  
JP1
  
952-3235-ND
  
0.711


  
1
  
Inductor 4.7uH
  
L1
  
1276-6213-1-ND
  
0.153


  
1
  
Capacitor 47uF 0603
  
C1
  
311-1897-1-ND
  
0.322


  
2
  
Capacitor 10uF 0603
  
C2,C3
  
587-3258-1-ND
  
0.238


  
10
  
Capacitor 0.1uF 0603
  
C4-C13
  
1276-1005-1-ND
  
0.073


  
6
  
Resistor 10K 0603
  
R1,R3,R5,R7,R9,R19
  
311-10KGRCT-ND
  
0.033


  
4
  
Resistor 100K 0603
  
R2,R4,R6,R8
  
311-100KGRCT-ND
  
0.029


  
1
  
Resistor 1K 0603
  
R10
  
311-1.0KGRCT-ND
  
0.010


  
1
  
Resistor 4.7K 0603
  
R21
  
311-4.7KGRCT-ND
  
0.010


  
1
  
Resistor 0.0 0603
  
R20
  
311-0.0GRCT-ND
  
0.010


  
8
  
Resistor 300 0603
  
R11-R18
  
311-300GRCT-ND
  
0.044


  
4
  
Standoffs M3 16mm Nylon
  
-
  
952-2188-ND
  
1.504


  
4
  
Screws M3 Nylon
  
-
  
36-29341-ND
  
0.748


  
1
  
PCB Lead-free, Shipped
  
-
  
-
  
3.240


  

  
Total per unit
  

  

  
18.20




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

Known Issues


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


Hardware Change Log


v1 - 01/30/2017


Initial release



RTL Change Log


v0.1.0 - 01/30/2017


Initial release



License

teatimer is <![CDATA[]]>CC-BY-4.0<![CDATA[]]> licensed. See the included LICENSE file.