add i2c pinout

README.md

@@ -13,6 +13,10 @@
   + [LSM303C](https://www.mouser.com/datasheet/2/389/lsm303agr-954987.pdf)
   + [MLX90614ESF](https://www.melexis.com/-/media/files/documents/datasheets/mlx90614-datasheet-melexis.pdf)
 
+  * Schematic
+    + [LSM303C](https://www.tme.eu/Document/3efb39d16e2f2e2f9f16bb5c89784b47/POLOLU-2127.pdf)
+    + [Adafruit LSM303C](https://learn.adafruit.com/lsm303-accelerometer-slash-compass-breakout?view=all)
+
 * Arduino Library
   + [GY271](.\arduino-lib\Mecha_QMC5883L)
   + [GY-906](https://github.com/adafruit/Adafruit-MLX90614-Library)
@@ -21,3 +25,32 @@
   + [GY271](https://www.instructables.com/id/Tutorial-to-Interface-HMC-5833L-With-Arduino-Uno/)
   + [GY-LSM303C](https://learn.adafruit.com/lsm303-accelerometer-slash-compass-breakout/coding)
   + [GY-906](https://create.arduino.cc/projecthub/SurtrTech/contactless-temperature-sensor-mlx90614-1e7bc7)
+
+* ESP8266
+  + Software controlled
+  + pin assignment defined
+  
+  ```
+  C:\Users\<user>\Documents\ArduinoData\packages\esp8266\hardware\esp8266\2.7.4\variants
+  ```
+  
+  + SCL / SDA pinout
+
+Description | SCL | SDA | Remark
+---|---|---|---
+Official | MTMS (GPIO14) | GPIO2 |
+Try | GPIO0 | GPIO2 |
+Try | GPIO5 | GPIO4 | Wire() Default for generic esp8266
+
+  + The change Wire default, update begin(SDA, SCL)
+  ```
+  Wire.begin(2, 0)
+  ```
+
+* ESP32
+  + Hardware Controlled
+  + Pinout
+
+Description | SCL | SDA | Remark
+---|---|---|---
+Official | GPIO22 | GPIO21 | Default