diff --git a/README.md b/README.md
index f37860c..177ef2f 100644
--- a/README.md
+++ b/README.md
@@ -1,5 +1,14 @@
 This firmware template is designed for development boards based around [STM32 F1 series micro-controller](http://www.st.com/web/en/catalog/mmc/FM141/SC1169/SS1031).
 
+SK6812RGBW DIN, PB15, SPI2_MOSI
+CATALEX RX, PA2, USART2_TX
+CATALEX TX, PA3, USART3_RX
+
+SK6812RGBW LED string
+orange: gnd
+green: 5v
+yellow: din
+
 project
 =======