Merge pull request #175 from MDLZCOOL/refactor-crc8-dvb-s2-func

Refactor crc8_dvb_s2 Function for Improved Readability and Maintainability

Author: pkendall64

lib/MSP/msp.cpp

@@ -1,6 +1,7 @@
 #include "msp.h"
 
 #include "logging.h"
+#include "crc.h"
 
 /* ==========================================
 MSP V2 Message Structure:
@@ -16,19 +17,11 @@ Offset: Usage:         In CRC:  Comment:
 n+8     checksum                uint8, (n= payload size), crc8_dvb_s2 checksum
 ========================================== */
 
-// CRC helper function. External to MSP class
-// TODO: Move all our CRC functions to a CRC lib
+// CRC helper function.
 uint8_t crc8_dvb_s2(uint8_t crc, unsigned char a)
 {
-    crc ^= a;
-    for (int ii = 0; ii < 8; ++ii) {
-        if (crc & 0x80) {
-            crc = (crc << 1) ^ 0xD5;
-        } else {
-            crc = crc << 1;
-        }
-    }
-    return crc;
+    static GENERIC_CRC8 crc8_dvb_s2_instance(0xD5);
+    return crc8_dvb_s2_instance.calc(crc ^ a);
 }
 
 MSP::MSP() : m_inputState(MSP_IDLE)