Historically,it was very important because rice was used as tax and salary,as salt did in ancient Greece.First mention about Masu can be found in the statute books written in early AC700,and it was used until 1964.
One day i found old Masu at flea market in Tokyo,which was built just after WW2 and used to measure liquid,maybe soy sauce or oil.
I decided to build a timer using this Masu and nixie tubes,both abandoned technologies.
it was my first touch for PCB CAD(i used EAGLE http://www.cadsoftusa.com) but finally i could design board schematics.
i ordered Olimex(http://www.olimex.com/) in Bulgaria to build my PCB.They did their job perfectlly.
i burned Arduino firmware to ATmega168 as controller.
All power is supplied via IEEE cable and no additional DC adapter is required.so that i can use it at coffee shop with my MacBook.
After soldering items,it fits to the inner space of Masu.
Drilling holes for nixie tubes and neon lamp at the bottom of Masu and upside down.Then it's done!
There are 3 switches and 1 volume.
switch1: power on/off
switch2: change mode between usual timer and pomodoro timer(repeat 5mins rest&25min work)
switch3: pause on/off
volume: adjust timer and rest span of pomodoro
i will reduce switch from 3 to 2 in next time.but as prototype,i'm totally satisfied.