Revision 4:f8128bb8bef1, committed 2016-11-17

Comitter:

qonico

Date:

Thu Nov 17 21:03:47 2016 +0000

Parent:

3:c8d0a2bb2987

Commit message:

Fix CRC case error

Changed in this revision

diff -r c8d0a2bb2987 -r f8128bb8bef1 DS1820.cpp
--- a/DS1820.cpp	Thu Nov 17 21:02:04 2016 +0000
+++ b/DS1820.cpp	Thu Nov 17 21:03:47 2016 +0000
@@ -196,54 +196,54 @@
 }
 
 bool DS1820::ROM_checksum_error() {
-    char CRC=0x00;
+    char crc=0x00;
     int i;
     for(i=0;i<7;i++) // Only going to shift the lower 7 bytes
-        CRC = CRC_byte(CRC, ROM[i]);
-    // After 7 bytes CRC should equal the 8th byte (ROM CRC)
-    return (CRC!=ROM[7]); // will return true if there is a CRC checksum error         
+        crc = crc_byte(crc, ROM[i]);
+    // After 7 bytes crc should equal the 8th byte (ROM crc)
+    return (crc!=ROM[7]); // will return true if there is a crc checksum error         
 }
 
 bool DS1820::RAM_checksum_error() {
-    char CRC=0x00;
+    char crc=0x00;
     int i;
     read_RAM();
     for(i=0;i<8;i++) // Only going to shift the lower 8 bytes
-        CRC = CRC_byte(CRC, RAM[i]);
-    // After 8 bytes CRC should equal the 9th byte (RAM CRC)
-    return (CRC!=RAM[8]); // will return true if there is a CRC checksum error         
+        crc = crc_byte(crc, RAM[i]);
+    // After 8 bytes crc should equal the 9th byte (RAM crc)
+    return (crc!=RAM[8]); // will return true if there is a crc checksum error         
 }
 
-char DS1820::CRC_byte (char CRC, char byte ) {
+char DS1820::crc_byte (char crc, char byte ) {
     int j;
     for(j=0;j<8;j++) {
-        if ((byte & 0x01 ) ^ (CRC & 0x01)) {
-            // DATA ^ LSB CRC = 1
-            CRC = CRC>>1;
+        if ((byte & 0x01 ) ^ (crc & 0x01)) {
+            // DATA ^ LSB crc = 1
+            crc = crc>>1;
             // Set the MSB to 1
-            CRC = CRC | 0x80;
+            crc = crc | 0x80;
             // Check bit 3
-            if (CRC & 0x04) {
-                CRC = CRC & 0xFB; // Bit 3 is set, so clear it
+            if (crc & 0x04) {
+                crc = crc & 0xFB; // Bit 3 is set, so clear it
             } else {
-                CRC = CRC | 0x04; // Bit 3 is clear, so set it
+                crc = crc | 0x04; // Bit 3 is clear, so set it
             }
             // Check bit 4
-            if (CRC & 0x08) {
-                CRC = CRC & 0xF7; // Bit 4 is set, so clear it
+            if (crc & 0x08) {
+                crc = crc & 0xF7; // Bit 4 is set, so clear it
             } else {
-                CRC = CRC | 0x08; // Bit 4 is clear, so set it
+                crc = crc | 0x08; // Bit 4 is clear, so set it
             }
         } else {
-            // DATA ^ LSB CRC = 0
-            CRC = CRC>>1;
+            // DATA ^ LSB crc = 0
+            crc = crc>>1;
             // clear MSB
-            CRC = CRC & 0x7F;
-            // No need to check bits, with DATA ^ LSB CRC = 0, they will remain unchanged
+            crc = crc & 0x7F;
+            // No need to check bits, with DATA ^ LSB crc = 0, they will remain unchanged
         }
         byte = byte>>1;
     }
-return CRC;
+return crc;
 }
 
 void DS1820::convert_temperature(devices device) {

diff -r c8d0a2bb2987 -r f8128bb8bef1 DS1820.h
--- a/DS1820.h	Thu Nov 17 21:02:04 2016 +0000
+++ b/DS1820.h	Thu Nov 17 21:03:47 2016 +0000
@@ -245,7 +245,7 @@
 
 private:
     bool _parasite_power;
-    char CRC_byte (char CRC, char byte );
+    char crc_byte (char crc, char byte );
     bool onewire_reset();
     void match_ROM();
     void skip_ROM();