add insert nuts url

docs/Instruction/tips/machine_building_parts_list.md

@@ -7,15 +7,15 @@ nuts
 bolts
 washers
 
-- [heat-set inserts](https://ja.aliexpress.com/item/4000232925592.html?spm=a2g0o.order_list.0.0.21ef585aR5dQVm&gatewayAdapt=glo2jpn)
+- [Heat-set inserts](https://ja.aliexpress.com/item/4000232925592.html?spm=a2g0o.order_list.0.0.21ef585aR5dQVm&gatewayAdapt=glo2jpn)
     - M3 X D5.0 X L3.8
     - M4 X D6.5 X L5.0
-- 鬼目ナット
-    - M3 × L5.5
+- Insert nuts: 鬼目ナット
+    - [M3 × L5.5](https://www.monotaro.com/p/4175/4824/?displayId=5)
         - Pre-hole 4.1～4.5, inner screw depth 3.5mm
-    - M3 × L8.5
+    - [M3 × L8.5](https://www.monotaro.com/p/4175/4833/?displayId=5)
         - Pre-hole 4.1～4.5, inner screw depth 4mm
-    - M4 x L10
+    - [M4 x L10](https://www.monotaro.com/p/4175/5165/?displayId=5)
         - Pre-hole 5.7～6, inner screw depth 7mm
 
 

docs/Instruction/tips/serial_communication.md

+# Serial communication
+
+## Arduino
+
+
+### Transmit
+
+`Serial.print`
+
+Syntax                      |Result        |-
+--                          |--            |
+Serial.print(78)            |  78          |
+Serial.print(78,DEC)        |  78          |
+Serial.print(1.234)         |1.23          |
+Serial.print(1.234,2)       |1.23          |
+Serial.print('N')           |  N           |
+Serial.print("Hello world.")|  Hello world.|
+
+
+`Serial.println`
+
+Syntax                      |Result        |-
+--                          |--            |
+Serial.println(78)          |78</br>_ (new line)      |serial_print_line
+Serial.print(78\n)          |78</br>_ (new line)      |need to chack </br>type "option + ¥" to \  
+
+
+`Serial.write`
+
+Syntax                      |Result        |-
+--                          |--            |
+Serial.write(1)             |0x01          |
+Serial.write(255)           |0xFF          |1 byte(0-255)
+Serial.write(256)           |0xFF          |cannot send more than 1 byte
+
+
+### Receive
+
+Serial.read
+Serial.readString()