diff --git a/electronic/README.md b/electronic/README.md
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@@ -4,118 +4,16 @@
 
 | Name       | Thumbnail                                                               | Required |
 | -------------- | ----------------------------------------------------------------------- | -------- |
-| Raspberry Pi Zero W<br>or<br>Raspberry Pi Zero W 2       | <img src="./imgs/zero2-close-up.webp" alt="raspberry pi" width="300"/>             | 1        |
-| body_bottom    | <img src="./imgs/body_bottom.jpg" alt="body_bottom" width="300"/>       | 1        |
-| body_side_wall | <img src="./imgs/body_side_wall.jpg" alt="body_side_wall" width="300"/> | 2        |
-| body_back_wall | <img src="./imgs/body_back_wall.jpg" alt="body_back_wall" width="300"/> | 1        |
-| battery_box    | <img src="./imgs/battery_box.jpg" alt="battery_box" width="300"/>       | 1        |
-| battery_holder | <img src="./imgs/battery_holder.jpg" alt="battery_holder" width="300"/> | 2        |
+| Raspberry Pi Zero W or W 2 | <img src="./imgs/zero2-close-up.webp" alt="raspberry pi" width="300"/> | 1        |
+| PCA9685 motor driver       | <img src="./imgs/PCA9685.jpg" alt="PCA9685" width="300"/>              | 2        |
+| XL4005 DC-DC step down     | <img src="./imgs/XL4005.jpg" alt="XL4005" width="300"/>                | 2        |
+| Mini 360 DC-DC step down   | <img src="./imgs/mini360.jpg" alt="mini360" width="300"/>              | 1        |
+| Toggle switch              | <img src="./imgs/toggle_switch.jpg" alt="toggle_switch" width="300"/>  | 1        |
+
 ## Connection Diagram
 
 ![connections](files/connections.jpg)
 
 
 
-### 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)
-