diff --git a/README.md b/README.md
index 398fc25..26b5075 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,9 @@
 # STM32-MCP2515
  C Driver for MCP2515 on STM32 MCU
+This is a backport of the C++ Arduino driver found here https://github.com/autowp/arduino-mcp2515
+
+SPI settings are hardcoded.
+
+Set the correct HAL includes for the target platform.  This has only been used on STM32F4 so far.
+
+I added the MCP_ prefix to the class functions, otherwise the documentations for that project should apply.