Add mozc-yunomi for Gboard Yunomi Version.

Change-Id: I0552641fe4a8ec8b7489332b1710e4d95869a02e

mozc-yunomi/README.md

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+# Gboard Yunomi version
+
+This contains programs, schematics and board layouts for Gboard Yunomi version,
+which was released on **Oct 1, 2021**.
+
+This is not an officially supported Google product.
+
+## Contents
+
+The directory structure is as follows:
+
+-   firmware/ : Arduino sketch.
+-   board/ : KiCad schematics and PCB layouts.
+-   jig.stl : A jig for building the keyboards.
+-   ../third_party/mozc-yunomi/keyswitches.pretty : Footprint data for the key
+    switches.
+
+## Building Gboard Yunomi Version
+
+![device](./images/device.jpg)
+
+### Parts
+
+-   Kailh choc key x60
+-   Diode (1N4148) x60
+-   ATMega32U4-AU (QFP)
+-   Resistor 10kOhm
+-   Resistor 22Ohm x2
+-   Capacitor 0.1uF
+-   Capacitor 1uF x2
+-   Capacitor 22pF x2
+-   Crystal 16MHz (HC-49)
+-   USB-C connector breakout (4pin)
+
+### PCBs
+
+We need two types of PCBs to build this project.
+
+![pcbs](./images/pcbs.jpg)
+
+#### Key-PCB
+
+![pcb1](./images/pcb1.png)
+
+Shape: Rectangular.
+
+Components: Diodes and key switches.
+
+Number of PCBs required: 12
+
+#### Base-PCB:
+
+![pcb2](./images/pcb2.png)
+
+Shape: Dodecagonal
+
+Component2: ATMega32u4.
+
+### Steps to build
+
+#### Step 1
+
+Solder diodes D1 to D5 onto the twelve Key-PCBs at the silk-screened locations.
+
+*IMPORTANT:* Diodes on six of the Key-PCB should be placed in the opposite
+direction.
+
+For six of the PCBs, we can solder diodes as indicated by the silk-screen. For
+the other six PCBs, we need to solder the diodes in the opposite direction.
+
+#### Step 2
+
+Solder key-switches to each Key-PCB. Note that the diodes need to be placed on
+the opposite side of the Key-PCB to the key-switches, as shown by the
+silk-screen.
+
+#### Step 3
+
+Create a cylindrical shape by combining the 12 Key-PCBs.
+
+There are six connection points between each pair of Key-PCBs. Connect adjacent
+pairs of boards by soldering the tin-plated wires (see the picture).
+
+However, only connect J11 and J12 between the first and last Key-PCB, instead of
+all six locations.
+
+![connect](./images/connect.png)
+
+![connect2](./images/connect2.jpg)
+
+![connect3](./images/connect3.jpg)
+
+If you have a 3D printer, you may print and use jig.stl to help with this step.
+
+#### Step 4
+
+Solder all parts for Base-PCB.
+
+#### Step 5
+
+Connect Base-PCB to the cylinder made in Step 3.
+
+![connect4](./images/connect4.jpg)
+
+#### Step 6
+
+Install the
+[Arduino caterina bootloader](https://github.com/arduino/ArduinoCore-avr/blob/master/bootloaders/caterina/Caterina-Leonardo.hex)
+using AVRISP or other ISP tool.
+
+#### Step 7
+
+Install firmware using the Arduino IDE.
+
+#### Step 8
+
+Connect the keyboard to a PC or other device that has Google Japanese
+Input/Gboard installed.
+
+## License
+
+```
+Licensed under the Apache License, Version 2.0 (the "License"); you may
+not use this file except in compliance with the License. You may obtain
+a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+```