diff --git a/docs/Bali_Fab_Fest_WS/index.md b/docs/Bali_Fab_Fest_WS/index.md
index a4656be628491562560ad0e7994bc4328691416c..05b66770d4d960232f5b3075077f43515355f9a8 100644
--- a/docs/Bali_Fab_Fest_WS/index.md
+++ b/docs/Bali_Fab_Fest_WS/index.md
@@ -208,8 +208,47 @@ GND<br/>A10<br/>A9<br/>A8|GND<br/>CLK<br/>DIO<br/>RST
 
 Download Eagle [sch](./codes/Xiao_SWD.sch) [brd](./codes/Xiao_SWD.brd)
 
+!!! Note
+    The pinheader that I used in this WS is Conthrough, Part Number: XB-3-4. [Maker site](https://www.mac8japan.com/products/217)  
+    ![](./images/conthrough.png)
+
+
 ## Useful Link
 
 [Embedded Computing : The $5 programmer-debugger](https://embeddedcomputing.weebly.com/the-5-programmer-debugger.html)
 
 ## Special Thanks to Seeed for sponsoring the Xiao boards  
+
+----
+
+## **WIP**: upload free_dap firmware to SWD D11C by uf2 file
+Ref. [Programmers Summary](http://pub.fabcloud.io/programmers/summary/)
+
+### Download
+
+class site:  [free_dap_d11c_mini.bin](http://academy.cba.mit.edu/classes/embedded_programming/SWD/free_dap_d11c_mini.bin)
+
+### Converter
+
+Ref. [.bin_.uf2_converter_site(JP)](https://lab.seeed.co.jp/entry/2021/03/29/120000)
+
+Converter site: [UF2](https://seeedjp.github.io/uf2/)
+
+![](./images/uf2_converter.png)  
+
+Download [free_dap_d11c_mini.uf2](./codes/free_dap_d11c_mini.uf2) from thin repo  
+
+!!! Note
+    UF2 (USB Flashing Format) is a name of a file format, developed by Microsoft, that is particularly suitable for flashing devices over MSC devices.  
+    Ref. [Seeed-Studio/uf2-samdx1](https://github.com/Seeed-Studio/uf2-samdx1)
+
+!!! Attention  
+    To use uf2 file, UF2 Bootloader is requiered in the board before hand.
+
+
+
+
+
+### uf2conv -- Packing and unpacking UF2 files
+
+[uf2conv -- Packing and unpacking UF2 files](https://github.com/microsoft/uf2/blob/master/utils/uf2conv.md)