fix: Fettling - More mocking exploration

Author: milesburton

.arduino_ci/crc16.h

@@ -0,0 +1,25 @@
+#ifndef CRC16_H
+#define CRC16_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Pure C implementation to replace the ASM version
+static inline uint16_t _crc16_update(uint16_t crc, uint8_t data) {
+    unsigned int i;
+    crc ^= data;
+    for (i = 0; i < 8; ++i) {
+        if (crc & 1)
+            crc = (crc >> 1) ^ 0xA001;
+        else
+            crc = (crc >> 1);
+    }
+    return crc;
+}
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif