diff --git a/README.md b/README.md
new file mode 100644
index 0000000..18ec932
--- /dev/null
+++ b/README.md
@@ -0,0 +1,8 @@
+# AIS_4G_EXTENSION_BOARD
+library for 4G extension board v1.0 
+Support sensor 
+- SHT20-x model
+- Lightsensor BH1750
+- Soil moisture (Capacitive Soil moisture v1.2 Analog sensor)
+- I/O Expander PCA9557 (builtin)
+- RTC PCF8563 (builtin)