Superseded by MaximInterface.

Diff: Authenticators/DS28E15_22_25/DS28E15_22_25.cpp

Revision:

77:529edb329ee0

Parent:

76:84e6c4994e29

Child:

78:0cbbac7f2016

diff -r 84e6c4994e29 -r 529edb329ee0 Authenticators/DS28E15_22_25/DS28E15_22_25.cpp
--- a/Authenticators/DS28E15_22_25/DS28E15_22_25.cpp	Sat May 14 14:27:56 2016 -0500
+++ b/Authenticators/DS28E15_22_25/DS28E15_22_25.cpp	Mon May 16 10:36:30 2016 -0500
@@ -137,8 +137,8 @@
     }
 }
 
-DS28E15_22_25::DS28E15_22_25(OneWireMaster & owMaster, bool lowVoltage)
-    : OneWireSlave(&owMaster), lowVoltage(lowVoltage)
+DS28E15_22_25::DS28E15_22_25(RandomAccessRomIterator & selector, bool lowVoltage)
+    : OneWireSlave(selector), lowVoltage(lowVoltage)
 {
     std::memset(manId, 0x00, manId.length);
 }
@@ -200,29 +200,34 @@
     uint8_t buf[256], cs;
     int cnt = 0;
     Mac mac;
+    
+    if (selectDevice() != OneWireMaster::Success)
+    {
+        return CommunicationError;
+    }
 
     buf[cnt++] = AuthWriteBlockProtection;
     buf[cnt++] = newProtection.statusByte();
 
     // Send command
-    p_owMaster->OWWriteBlock(&buf[0], 2);
+    master().OWWriteBlock(&buf[0], 2);
 
     // read first CRC byte
-    p_owMaster->OWReadByte(buf[cnt++]);
+    master().OWReadByte(buf[cnt++]);
 
     // read the last CRC and enable
-    p_owMaster->OWReadBytePower(buf[cnt++]);
+    master().OWReadBytePower(buf[cnt++]);
 
     // now wait for the MAC computation.
     wait_ms(shaComputationDelayMs);
 
     // disable strong pullup
-    p_owMaster->OWSetLevel(OneWireMaster::NormalLevel);
+    master().OWSetLevel(OneWireMaster::NormalLevel);
 
     // check CRC16
     if (OneWireMaster::calculateCrc16(buf, 0, cnt) != 0xB001)
     {
-        return CommunicationError;
+        return CrcError;
     }
 
     ISha256MacCoproc::CmdResult result;
@@ -234,16 +239,16 @@
     cnt = 0;
 
     // send the MAC
-    p_owMaster->OWWriteBlock(mac, mac.length);
+    master().OWWriteBlock(mac, mac.length);
 
     // Read CRC and CS byte
-    p_owMaster->OWReadBlock(&buf[cnt], 3);
+    master().OWReadBlock(&buf[cnt], 3);
     cnt += 3;
 
     // check CRC16
     if (OneWireMaster::calculateCrc16(buf, 0, (cnt - 1), OneWireMaster::calculateCrc16(mac, 0, mac.length)) != 0xB001)
     {
-        return CommunicationError;
+        return CrcError;
     }
 
     // check CS
@@ -254,16 +259,16 @@
 
     // send release and strong pull-up
     // DATASHEET_CORRECTION - last bit in release is a read-zero so don't check echo of write byte
-    p_owMaster->OWWriteBytePower(0xAA);
+    master().OWWriteBytePower(0xAA);
 
     // now wait for the programming.
     wait_ms(eepromWriteDelayMs);
 
     // disable strong pullup
-    p_owMaster->OWSetLevel(OneWireMaster::NormalLevel);
+    master().OWSetLevel(OneWireMaster::NormalLevel);
 
     // read the CS byte
-    p_owMaster->OWReadByte(cs);
+    master().OWReadByte(cs);
 
     if (cs == 0xAA)
     {
@@ -277,35 +282,40 @@
 {
     uint8_t buf[256], cs;
     int cnt = 0;
+    
+    if (selectDevice() != OneWireMaster::Success)
+    {
+        return CommunicationError;
+    }
 
     buf[cnt++] = WriteBlockProtection;
 
     // compute parameter byte 
     buf[cnt++] = protection.statusByte();
 
-    p_owMaster->OWWriteBlock(&buf[0], cnt);
+    master().OWWriteBlock(&buf[0], cnt);
 
     // Read CRC
-    p_owMaster->OWReadBlock(&buf[cnt], 2);
+    master().OWReadBlock(&buf[cnt], 2);
     cnt += 2;
 
     // check CRC16
     if (OneWireMaster::calculateCrc16(buf, 0, cnt) != 0xB001)
     {
-        return CommunicationError;
+        return CrcError;
     }
 
     // sent release
-    p_owMaster->OWWriteBytePower(0xAA);
+    master().OWWriteBytePower(0xAA);
 
     // now wait for the programming.
     wait_ms(eepromWriteDelayMs);
 
     // disable strong pullup
-    p_owMaster->OWSetLevel(OneWireMaster::NormalLevel);
+    master().OWSetLevel(OneWireMaster::NormalLevel);
 
     // read the CS byte
-    p_owMaster->OWReadByte(cs);
+    master().OWReadByte(cs);
 
     if (cs == 0xAA)
     {
@@ -318,7 +328,9 @@
 OneWireSlave::CmdResult DS28E15_22_25::readBlockProtection(unsigned int blockNum, BlockProtection & protection)
 {
     uint8_t buf;
-    CmdResult result = readStatus(false, false, blockNum, &buf);
+    CmdResult result;
+    
+    result = readStatus(false, false, blockNum, &buf);
     if (result == Success)
     {
         protection.setStatusByte(buf);
@@ -361,6 +373,11 @@
 
     uint8_t buf[256];
     size_t cnt = 0, offset = 0;
+    
+    if (selectDevice() != OneWireMaster::Success)
+    {
+        return CommunicationError;
+    }
 
     buf[cnt++] = ReadStatus;
     if (personality)
@@ -383,7 +400,7 @@
     }
 
     // send the command
-    p_owMaster->OWWriteBlock(&buf[0], 2);
+    master().OWWriteBlock(&buf[0], 2);
 
     offset = cnt + 2;
 
@@ -408,13 +425,13 @@
     rdnum += crcLen; // Add in CRC length
 
     // Read the bytes 
-    p_owMaster->OWReadBlock(&buf[cnt], rdnum);
+    master().OWReadBlock(&buf[cnt], rdnum);
     cnt += rdnum;
 
     // check the first CRC16
     if (OneWireMaster::calculateCrc16(buf, 0, offset) != 0xB001)
     {
-        return CommunicationError;
+        return CrcError;
     }
 
     if (personality || allpages)
@@ -422,7 +439,7 @@
         // check the second CRC16
         if (OneWireMaster::calculateCrc16(buf, offset, (cnt - offset)) != 0xB001)
         {
-            return CommunicationError;
+            return CrcError;
         }
     }
 
@@ -477,45 +494,50 @@
 {
     uint8_t buf[256], cs;
     int cnt = 0;
+    
+    if (selectDevice() != OneWireMaster::Success)
+    {
+        return CommunicationError;
+    }
 
     buf[cnt++] = ComputePageMac;
     buf[cnt++] = ((anon) ? 0xE0 : 0x00) | page_num;
 
     // Send command
-    p_owMaster->OWWriteBlock(&buf[0], 2);
+    master().OWWriteBlock(&buf[0], 2);
 
     // read first CRC byte
-    p_owMaster->OWReadByte(buf[cnt++]);
+    master().OWReadByte(buf[cnt++]);
 
     // read the last CRC and enable
-    p_owMaster->OWReadBytePower(buf[cnt++]);
+    master().OWReadBytePower(buf[cnt++]);
 
     // now wait for the MAC computation.
     wait_ms(shaComputationDelayMs * 2);
 
     // disable strong pullup
-    p_owMaster->OWSetLevel(OneWireMaster::NormalLevel);
+    master().OWSetLevel(OneWireMaster::NormalLevel);
 
     // check CRC16
     if (OneWireMaster::calculateCrc16(buf, 0, cnt) != 0xB001)
     {
-        return CommunicationError;
+        return CrcError;
     }
 
     // read the CS byte
-    p_owMaster->OWReadByte(cs);
+    master().OWReadByte(cs);
     if (cs != 0xAA)
     {
         return OperationFailure;
     }
 
     // read the MAC and CRC
-    p_owMaster->OWReadBlock(&buf[0], (Mac::length + 2));
+    master().OWReadBlock(&buf[0], (Mac::length + 2));
 
     // check CRC16
     if (OneWireMaster::calculateCrc16(buf, 0, (Mac::length + 2)) != 0xB001)
     {
-        return CommunicationError;
+        return CrcError;
     }
 
     // copy MAC to return buffer
@@ -528,34 +550,39 @@
 {
     uint8_t buf[256], cs;
     int cnt = 0;
+    
+    if (selectDevice() != OneWireMaster::Success)
+    {
+        return CommunicationError;
+    }
 
     buf[cnt++] = ComputeAndLockSecret;
     buf[cnt++] = (lock) ? (0xE0 | page_num) : page_num;  // lock flag 
 
     // Send command
-    p_owMaster->OWWriteBlock(&buf[0], 2);
+    master().OWWriteBlock(&buf[0], 2);
 
     // Read CRC
-    p_owMaster->OWReadBlock(&buf[cnt], 2);
+    master().OWReadBlock(&buf[cnt], 2);
     cnt += 2;
 
     // check CRC16
     if (OneWireMaster::calculateCrc16(buf, 0, cnt) != 0xB001)
     {
-        return CommunicationError;
+        return CrcError;
     }
 
     // send release and strong pull-up
-    p_owMaster->OWWriteBytePower(0xAA);
+    master().OWWriteBytePower(0xAA);
 
     // now wait for the MAC computations and secret programming.
     wait_ms(shaComputationDelayMs * 2 + secretEepromWriteDelayMs());
 
     // disable strong pullup
-    p_owMaster->OWSetLevel(OneWireMaster::NormalLevel);
+    master().OWSetLevel(OneWireMaster::NormalLevel);
 
     // read the CS byte
-    p_owMaster->OWReadByte(cs);
+    master().OWReadByte(cs);
 
     if (cs == 0xAA)
     {
@@ -569,6 +596,11 @@
 {
     uint8_t buf[256];
     int cnt = 0, offset;
+    
+    if (selectDevice() != OneWireMaster::Success)
+    {
+        return CommunicationError;
+    }
 
     buf[cnt++] = ReadWriteScratchpad;
     if ((romId.familyCode() == DS28E25_Family) || (romId.familyCode() == DS28E22_Family))
@@ -581,10 +613,10 @@
     }
 
     // Send command
-    p_owMaster->OWWriteBlock(&buf[0], 2);
+    master().OWWriteBlock(&buf[0], 2);
 
     // Read CRC
-    p_owMaster->OWReadBlock(&buf[cnt], 2);
+    master().OWReadBlock(&buf[cnt], 2);
     cnt += 2;
 
     offset = cnt;
@@ -594,22 +626,22 @@
     cnt += data.length;
 
     // Send the data
-    p_owMaster->OWWriteBlock(data, data.length);
+    master().OWWriteBlock(data, data.length);
 
     // Read CRC
-    p_owMaster->OWReadBlock(&buf[cnt], 2);
+    master().OWReadBlock(&buf[cnt], 2);
     cnt += 2;
 
     // check first CRC16
     if (OneWireMaster::calculateCrc16(buf, 0, offset) != 0xB001)
     {
-        return CommunicationError;
+        return CrcError;
     }
 
     // check the second CRC16
     if (OneWireMaster::calculateCrc16(buf, offset, (cnt - offset)) != 0xB001)
     {
-        return CommunicationError;
+        return CrcError;
     }
 
     return Success;
@@ -619,6 +651,11 @@
 {
     uint8_t buf[256];
     int cnt = 0, offset;
+    
+    if (selectDevice() != OneWireMaster::Success)
+    {
+        return CommunicationError;
+    }
 
     buf[cnt++] = ReadWriteScratchpad;
     if ((romId.familyCode() == DS28E25_Family) || (romId.familyCode() == DS28E22_Family))
@@ -631,32 +668,32 @@
     }
 
     // Send command
-    p_owMaster->OWWriteBlock(&buf[0], 2);
+    master().OWWriteBlock(&buf[0], 2);
 
     // Read CRC
-    p_owMaster->OWReadBlock(&buf[cnt], 2);
+    master().OWReadBlock(&buf[cnt], 2);
     cnt += 2;
 
     offset = cnt;
 
     // Receive the data
-    p_owMaster->OWReadBlock(&buf[cnt], data.length);
+    master().OWReadBlock(&buf[cnt], data.length);
     cnt += data.length;
 
     // Read CRC
-    p_owMaster->OWReadBlock(&buf[cnt], 2);
+    master().OWReadBlock(&buf[cnt], 2);
     cnt += 2;
 
     // check first CRC16
     if (OneWireMaster::calculateCrc16(buf, 0, offset) != 0xB001)
     {
-        return CommunicationError;
+        return CrcError;
     }
 
     // check the second CRC16
     if (OneWireMaster::calculateCrc16(buf, offset, (cnt - offset)) != 0xB001)
     {
-        return CommunicationError;
+        return CrcError;
     }
 
     // Copy to output
@@ -669,34 +706,39 @@
 {
     uint8_t buf[256], cs;
     int cnt = 0;
+    
+    if (selectDevice() != OneWireMaster::Success)
+    {
+        return CommunicationError;
+    }
 
     buf[cnt++] = LoadAndLockSecret;
     buf[cnt++] = (lock) ? 0xE0 : 0x00;  // lock flag 
 
     // Send command
-    p_owMaster->OWWriteBlock(&buf[0], 2);
+    master().OWWriteBlock(&buf[0], 2);
 
     // Read CRC
-    p_owMaster->OWReadBlock(&buf[cnt], 2);
+    master().OWReadBlock(&buf[cnt], 2);
     cnt += 2;
 
     // check CRC16
     if (OneWireMaster::calculateCrc16(buf, 0, cnt) != 0xB001)
     {
-        return CommunicationError;
+        return CrcError;
     }
 
     // send release and strong pull-up
-    p_owMaster->OWWriteBytePower(0xAA);
+    master().OWWriteBytePower(0xAA);
 
     // now wait for the secret programming.
     wait_ms(secretEepromWriteDelayMs());
 
     // disable strong pullup
-    p_owMaster->OWSetLevel(OneWireMaster::NormalLevel);
+    master().OWSetLevel(OneWireMaster::NormalLevel);
 
     // read the CS byte
-    p_owMaster->OWReadByte(cs);
+    master().OWReadByte(cs);
 
     if (cs == 0xAA)
     {
@@ -717,21 +759,26 @@
     // check if not continuing a previous block write
     if (!continuing)
     {
+        if (selectDevice() != OneWireMaster::Success)
+        {
+            return CommunicationError;
+        }
+        
         buf[cnt++] = ReadMemory;
         buf[cnt++] = page;   // address 
 
         // Send command
-        p_owMaster->OWWriteBlock(&buf[0], 2);
+        master().OWWriteBlock(&buf[0], 2);
 
         // Read CRC
-        p_owMaster->OWReadBlock(&buf[cnt], 2);
+        master().OWReadBlock(&buf[cnt], 2);
         cnt += 2;
 
         offset = cnt;
     }
 
     // read data and CRC16
-    p_owMaster->OWReadBlock(&buf[cnt], (rdbuf.length + 2));
+    master().OWReadBlock(&buf[cnt], (rdbuf.length + 2));
     cnt += 34;
 
     // check the first CRC16
@@ -739,14 +786,14 @@
     {
         if (OneWireMaster::calculateCrc16(buf, 0, offset) != 0xB001)
         {
-            return CommunicationError;
+            return CrcError;
         }
     }
 
     // check the second CRC16
     if (OneWireMaster::calculateCrc16(buf, offset, (cnt - offset)) != 0xB001)
     {
-        return CommunicationError;
+        return CrcError;
     }
 
     // copy the data to the read buffer
@@ -766,14 +813,19 @@
     // check if not continuing a previous block write
     if (!continuing)
     {
+        if (selectDevice() != OneWireMaster::Success)
+        {
+            return CommunicationError;
+        }
+        
         buf[cnt++] = AuthWriteMemory;
         buf[cnt++] = (segmentNum << 5) | pageNum;   // address 
 
         // Send command
-        p_owMaster->OWWriteBlock(&buf[0], 2);
+        master().OWWriteBlock(&buf[0], 2);
 
         // Read CRC
-        p_owMaster->OWReadBlock(&buf[cnt], 2);
+        master().OWReadBlock(&buf[cnt], 2);
         cnt += 2;
 
         offset = cnt;
@@ -786,26 +838,26 @@
     }
 
     // Send data
-    p_owMaster->OWWriteBlock(newData, newData.length);
+    master().OWWriteBlock(newData, newData.length);
 
     // read first CRC byte
-    p_owMaster->OWReadByte(buf[cnt++]);
+    master().OWReadByte(buf[cnt++]);
 
     // read the last CRC and enable power
-    p_owMaster->OWReadBytePower(buf[cnt++]);
+    master().OWReadBytePower(buf[cnt++]);
 
     // now wait for the MAC computation.
     wait_ms(shaComputationDelayMs);
 
     // disable strong pullup
-    p_owMaster->OWSetLevel(OneWireMaster::NormalLevel);
+    master().OWSetLevel(OneWireMaster::NormalLevel);
 
     // check the first CRC16
     if (!continuing)
     {
         if (OneWireMaster::calculateCrc16(buf, 0, offset) != 0xB001)
         {
-            return CommunicationError;
+            return CrcError;
         }
     }
 
@@ -825,17 +877,17 @@
 
     if (CRC16 != 0xB001)
     {
-        return CommunicationError;
+        return CrcError;
     }
 
     // transmit MAC as a block
-    p_owMaster->OWWriteBlock(mac, mac.length);
+    master().OWWriteBlock(mac, mac.length);
 
     // calculate CRC on MAC
     CRC16 = OneWireMaster::calculateCrc16(mac, 0, mac.length);
 
     // append read of CRC16 and CS byte
-    p_owMaster->OWReadBlock(&buf[0], 3);
+    master().OWReadBlock(&buf[0], 3);
     cnt = 3;
 
     // ckeck CRC16
@@ -843,7 +895,7 @@
 
     if (CRC16 != 0xB001)
     {
-        return CommunicationError;
+        return CrcError;
     }
 
     // check CS
@@ -853,16 +905,16 @@
     }
 
     // send release and strong pull-up
-    p_owMaster->OWWriteBytePower(0xAA);
+    master().OWWriteBytePower(0xAA);
 
     // now wait for the programming.
     wait_ms(eepromWriteDelayMs);
 
     // disable strong pullup
-    p_owMaster->OWSetLevel(OneWireMaster::NormalLevel);
+    master().OWSetLevel(OneWireMaster::NormalLevel);
 
     // read the CS byte
-    p_owMaster->OWReadByte(cs);
+    master().OWReadByte(cs);
 
     if (cs == 0xAA)
     {
@@ -933,14 +985,19 @@
     // check if not continuing a previous block write
     if (!continuing)
     {
+        if (selectDevice() != OneWireMaster::Success)
+        {
+            return CommunicationError;
+        }
+        
         buf[cnt++] = AuthWriteMemory;
         buf[cnt++] = (segmentNum << 5) | pageNum;   // address 
 
         // Send command
-        p_owMaster->OWWriteBlock(&buf[0], 2);
+        master().OWWriteBlock(&buf[0], 2);
 
         // Read CRC
-        p_owMaster->OWReadBlock(&buf[cnt], 2);
+        master().OWReadBlock(&buf[cnt], 2);
         cnt += 2;
 
         offset = cnt;
@@ -953,26 +1010,26 @@
     }
 
     // Send data
-    p_owMaster->OWWriteBlock(newData, newData.length);
+    master().OWWriteBlock(newData, newData.length);
 
     // read first CRC byte
-    p_owMaster->OWReadByte(buf[cnt++]);
+    master().OWReadByte(buf[cnt++]);
 
     // read the last CRC and enable power
-    p_owMaster->OWReadBytePower(buf[cnt++]);
+    master().OWReadBytePower(buf[cnt++]);
 
     // now wait for the MAC computation.
     wait_ms(shaComputationDelayMs);
 
     // disable strong pullup
-    p_owMaster->OWSetLevel(OneWireMaster::NormalLevel);
+    master().OWSetLevel(OneWireMaster::NormalLevel);
 
     // check the first CRC16
     if (!continuing)
     {
         if (OneWireMaster::calculateCrc16(buf, 0, offset) != 0xB001)
         {
-            return CommunicationError;
+            return CrcError;
         }
     }
 
@@ -990,7 +1047,7 @@
 
     if (CRC16 != 0xB001)
     {
-        return CommunicationError;
+        return CrcError;
     }
 
     // compute the mac
@@ -1003,13 +1060,13 @@
     }
 
     // transmit MAC as a block
-    p_owMaster->OWWriteBlock(mac, mac.length);
+    master().OWWriteBlock(mac, mac.length);
 
     // calculate CRC on MAC
     CRC16 = OneWireMaster::calculateCrc16(mac, 0, mac.length);
 
     // append read of CRC16 and CS byte
-    p_owMaster->OWReadBlock(&buf[0], 3);
+    master().OWReadBlock(&buf[0], 3);
     cnt = 3;
 
     // ckeck CRC16
@@ -1017,7 +1074,7 @@
 
     if (CRC16 != 0xB001)
     {
-        return CommunicationError;
+        return CrcError;
     }
 
     // check CS
@@ -1027,16 +1084,16 @@
     }
 
     // send release and strong pull-up
-    p_owMaster->OWWriteBytePower(0xAA);
+    master().OWWriteBytePower(0xAA);
 
     // now wait for the programming.
     wait_ms(eepromWriteDelayMs);
 
     // disable strong pullup
-    p_owMaster->OWSetLevel(OneWireMaster::NormalLevel);
+    master().OWSetLevel(OneWireMaster::NormalLevel);
 
     // read the CS byte
-    p_owMaster->OWReadByte(cs);
+    master().OWReadByte(cs);
 
     if (cs == 0xAA)
     {
@@ -1053,25 +1110,30 @@
 
     if (!continuing)
     {
+        if (selectDevice() != OneWireMaster::Success)
+        {
+            return CommunicationError;
+        }
+        
         buf[0] = ReadMemory;
         buf[1] = (segment << 5) | page;
 
         // Transmit command
-        p_owMaster->OWWriteBlock(buf, 2);
+        master().OWWriteBlock(buf, 2);
 
         // Receive CRC
-        result = p_owMaster->OWReadBlock(buf, 2);
+        result = master().OWReadBlock(buf, 2);
     }
     else if (segment == 0)
     {
         // Receive CRC from previous read
-        result = p_owMaster->OWReadBlock(buf, 2);
+        result = master().OWReadBlock(buf, 2);
     }
 
     // Receive data
     if (result == OneWireMaster::Success)
     {
-        result = p_owMaster->OWReadBlock(data, data.length);
+        result = master().OWReadBlock(data, data.length);
     }
 
     return (result == OneWireMaster::Success ? OneWireSlave::Success : OneWireSlave::CommunicationError);
@@ -1088,14 +1150,19 @@
     // check if not continuing a previous block write
     if (!continuing)
     {
+        if (selectDevice() != OneWireMaster::Success)
+        {
+            return CommunicationError;
+        }
+        
         buf[cnt++] = WriteMemory;
         buf[cnt++] = (block << 5) | page;   // address 
 
         // Send command 
-        p_owMaster->OWWriteBlock(&buf[0], 2);
+        master().OWWriteBlock(&buf[0], 2);
 
         // Read CRC
-        p_owMaster->OWReadBlock(&buf[cnt], 2);
+        master().OWReadBlock(&buf[cnt], 2);
         cnt += 2;
 
         offset = cnt;
@@ -1108,10 +1175,10 @@
     }
 
     // Send data
-    p_owMaster->OWWriteBlock(data, data.length);
+    master().OWWriteBlock(data, data.length);
 
     // Read CRC
-    p_owMaster->OWReadBlock(&buf[cnt], 2);
+    master().OWReadBlock(&buf[cnt], 2);
     cnt += 2;
 
     // check the first CRC16
@@ -1119,27 +1186,27 @@
     {
         if (OneWireMaster::calculateCrc16(buf, 0, offset) != 0xB001)
         {
-            return CommunicationError;
+            return CrcError;
         }
     }
 
     // check the second CRC16
     if (OneWireMaster::calculateCrc16(buf, offset, (cnt - offset)) != 0xB001)
     {
-        return CommunicationError;
+        return CrcError;
     }
 
     // send release and strong pull-up
-    p_owMaster->OWWriteBytePower(0xAA);
+    master().OWWriteBytePower(0xAA);
 
     // now wait for the programming.
     wait_ms(eepromWriteDelayMs);
 
     // disable strong pullup
-    p_owMaster->OWSetLevel(OneWireMaster::NormalLevel);
+    master().OWSetLevel(OneWireMaster::NormalLevel);
 
     // read the CS byte
-    p_owMaster->OWReadByte(cs);
+    master().OWReadByte(cs);
 
     if (cs == 0xAA)
     {