text: # Electronics
  
  ## Connection Diagram
  
  ![connections](files/connections.jpg)
  
  ## Bill of Materials (BOM)
  
  ### PCB
  
  Name | Thumbnail | Required | Note |
  -------- | --------- | -------- | ---- | 
  main | ![main](files/main_pcb_s.jpg) | 1 |
  sub | ![sub](files/sub_pcb_s.jpg) | 2 | there is a difference (SJ1) between<br>the 2 PCB, refer to below
  
  ### Components
  
  Name | Thumbnail | Required | Note |
  -------- | --------- | -------- | ---- | 
  [Linkit 7697](https://labs.mediatek.com/zh-tw/platform/linkit-7697) | <img width=200 src='https://labs.mediatek.com/images/img_hdk_7697.png'/> | 1 |
  [mini360 DC-DC](https://www.aliexpress.com/w/wholesale-mini360-dc-dc.html) Buck voltage regulator | ![](files/mini360.png) | 7 | adjust to 5V
  [PCA9685](https://cdn-shop.adafruit.com/datasheets/PCA9685.pdf) (TSSOP28)| ![](files/pca9685.png) | 2 | TSSOP28 |
  Resistor: 220 ohm (0805) | | 18 | SMD |
  Resistor: 10K ohm (0805) | | 12 | SMD |
  Resistor: 470 ohm (0805) | | 1 | SMD |
  LED: green or any color (0805) | | 1 | SMD |
  Capacitor: 10 uF (0805) | | 2 | SMD |
  14 pin 2.54mm female header | | 4 |
  4 pin 2.54mm female header | | 2 |
  6 pin 2.54mm female header | | 2 |
  4 pin 2.54mm 90 degress male header | | 2 |
  6 pin 2.54mm 90 degress male header | | 2 |
  4 pin 2.54mm male header | | 2 |
  3 pin 2.54mm male header (black) | | 6 |
  3 pin 2.54mm male header (yellow) | | 6 |
  3 pin 2.54mm male header (red) | | 6 |
  2 pin 2.54mm male header | | 1 |
  Jumper 2.54mm | | 1 |
  
  ## PCB detail
  
  
  ##### Software 
  
  Please use **Eagle 7.7** software to open schematic files (main.sch/main.brd and sub.sch/sub.brd)
  
  Eagle 7.7 can be found at http://eagle.autodesk.com/eagle/software-versions/1
  
      Note.
      7.7 is an old and free version of Eagle. 
      Latest Eagle is not free anymore unless you are students
  
  ##### Manufacture
  
  There are a lot of online service that can manufacture PCB/PCBA for you (just google `PCB/PCBA`).
  
  Seeed (https://www.seeedstudio.io/fusion_pcb.html) is one of them.
  
  They also provide instructions of generating necessary Gerber files at http://support.seeedstudio.com/knowledgebase/articles/1176532-how-to-generate-gerber-file.
  
  
  ### Main
  
  `main.brd`/`main.sch`
  
  ##### Schematic
  
  ![main_sch](files/main_sch.png)
  
      Note.
      `MP2307` refer to mini360 DC-DC converter
  
  ##### Layout
  
  ![main_brd](files/main_brd.png)
  
  ##### PCB
  
  ![main_pcb](files/main_pcb_l.jpg)
  
  
  ### Sub (x2)
  
  `sub.brd`/`usb.sch`
  
  > There is 1 difference between left and right PCB. The SJ1 of right PCB is left open, but `SJ1` of left PCB should be **closed**. (This is i2c address setting of PCB9865)
  
  ##### Schematic
  
  ![sub_sch](files/sub_sch.png)
  
      Note.
      `MP2307` refer to mini360 DC-DC converter
  
  ##### Layout
  
  ![sub_brd](files/sub_brd.png)
  
  ##### PCB
  
  ![sub_pcb](files/sub_pcb_l.jpg)
  
  ## Servo Connection
  
  Each leg of hexapod has 3 servos (body, thigh, foot), refer to below diagram for correct connection
  
  ![leg](files/leg.png)
  
  ![servo_conn](files/servo_conn.jpg)
  
  
  