diff --git a/CISLibrary/tools/CRC.cpp b/CISLibrary/tools/CRC.cpp
new file mode 100644
index 00000000..7ceb5b35
--- /dev/null
+++ b/CISLibrary/tools/CRC.cpp
@@ -0,0 +1,22 @@
+#pragma once
+
+#include "CRC.h"
+
+#define key 0x2F
+
+char CRC8(const char * data, int length) {
+  char crc = 0x00;
+  for (int i = 0; i < length; ++i) {
+    crc ^= *(data + i);
+
+    for (int j = 0; j < 8; ++j) {
+      if ((crc & 0x80)) {
+        crc = ((crc << 1) ^ key);
+      } else {
+        crc <<= 1;
+      }
+    }
+  }
+
+  return crc;
+}
\ No newline at end of file
diff --git a/CISLibrary/tools/CRC.h b/CISLibrary/tools/CRC.h
new file mode 100644
index 00000000..5ff87436
--- /dev/null
+++ b/CISLibrary/tools/CRC.h
@@ -0,0 +1,3 @@
+#pragma once
+
+char CRC8(const char * data, int length);
\ No newline at end of file
diff --git a/CougSat1-ADCS/docs/IHU communication.pdf b/CougSat1-ADCS/docs/IHU communication.pdf
new file mode 100644
index 00000000..08d36756
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diff --git a/CougSat1-IHU/docs/IHU communication.pdf b/CougSat1-IHU/docs/IHU communication.pdf
new file mode 100644
index 00000000..08d36756
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