Diff: crc.cpp

Revision:

80:83b0d879cc32

Parent:

78:0cbbac7f2016

--- a/crc.cpp	Mon May 23 18:57:12 2016 -0500
+++ b/crc.cpp	Thu Jun 02 21:56:16 2016 +0000
@@ -1,5 +1,36 @@
+
+
 #include "crc.h"
 
+
+uint8_t OneWire::crc::calculateCrc8(uint8_t crc8, uint8_t data)
+{
+    // See Application Note 27
+    crc8 = crc8 ^ data;
+    for (int i = 0; i < 8; i++)
+    {
+        if (crc8 & 1)
+        {
+            crc8 = (crc8 >> 1) ^ 0x8c;
+        }
+        else
+        {
+            crc8 = (crc8 >> 1);
+        }
+    }
+ 
+    return crc8;
+}
+ 
+uint8_t OneWire::crc::calculateCrc8(const uint8_t * data, size_t dataLen, uint8_t crc)
+{
+    for (size_t i = 0; i < dataLen; i++)
+    {
+        crc = calculateCrc8(crc, data[i]);
+    }
+    return crc;
+}
+ 
 uint16_t OneWire::crc::calculateCrc16(uint16_t crc16, uint16_t data)
 {
     const uint16_t oddparity[] = { 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0 };