Diff: RomCommands.cpp

Revision:

76:84e6c4994e29

diff -r 8b627804927c -r 84e6c4994e29 RomCommands.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/RomCommands.cpp	Sat May 14 14:27:56 2016 -0500
@@ -0,0 +1,334 @@
+#include "RomCommands.h"
+
+using namespace OneWire;
+
+enum OwRomCmd
+{
+    ReadRomCmd = 0x33,
+    MatchRomCmd = 0x55,
+    SearchRomCmd = 0xF0,
+    SkipRomCmd = 0xCC,
+    ResumeCmd = 0xA5,
+    OverdriveSkipRomCmd = 0x3C,
+    OverdriveMatchRomCmd = 0x69
+};
+
+OneWireMaster::CmdResult RomCommands::OWFirst(OneWireMaster & owMaster, SearchState & searchState)
+{
+    // Reset and begin a new search
+    searchState.reset();
+    return OWSearch(owMaster, searchState);
+}
+
+OneWireMaster::CmdResult RomCommands::OWNext(OneWireMaster & owMaster, SearchState & searchState)
+{
+    // Continue the previous search
+    return OWSearch(owMaster, searchState);
+}
+
+OneWireMaster::CmdResult RomCommands::OWVerify(OneWireMaster & owMaster, const RomId & romId)
+{
+    OneWireMaster::CmdResult result;
+    SearchState searchState;
+
+    searchState.romId = romId;
+
+    // set search to find the same device
+    searchState.last_discrepancy = 64;
+    searchState.last_device_flag = false;
+
+    result = OWSearch(owMaster, searchState);
+    if (result == OneWireMaster::Success)
+    {
+        // check if same device found
+        if (romId != searchState.romId)
+        {
+            result = OneWireMaster::OperationFailure;
+        }
+    }
+
+    return result;
+}
+
+void RomCommands::OWTargetSetup(SearchState & searchState)
+{
+    // set the search state to find SearchFamily type devices
+    uint8_t familyCode = searchState.romId.familyCode();
+    searchState.reset();
+    searchState.romId.setFamilyCode(familyCode);
+    searchState.last_discrepancy = 64;
+}
+
+void RomCommands::OWFamilySkipSetup(SearchState & searchState)
+{
+    // set the Last discrepancy to last family discrepancy
+    searchState.last_discrepancy = searchState.last_family_discrepancy;
+
+    // clear the last family discrpepancy
+    searchState.last_family_discrepancy = 0;
+
+    // check for end of list
+    if (searchState.last_discrepancy == 0)
+    {
+        searchState.last_device_flag = true;
+    }
+}
+
+OneWireMaster::CmdResult RomCommands::OWReadRom(OneWireMaster & owMaster, RomId & romId)
+{
+    OneWireMaster::CmdResult result;
+    RomId readId;
+
+    result = owMaster.OWReset();
+    if (result == OneWireMaster::Success)
+    {
+        result = owMaster.OWWriteByte(ReadRomCmd);
+    }
+
+    // read the ROM
+    if (result == OneWireMaster::Success)
+    {
+        result = owMaster.OWReadBlock(readId, RomId::byteLen);
+    }
+
+    // verify CRC8
+    if (result == OneWireMaster::Success)
+    {
+        if (readId.crc8Valid())
+        {
+            romId = readId;
+        }
+        else
+        {
+            result = OneWireMaster::OperationFailure;
+        }
+    }
+
+    return result;
+}
+  
+OneWireMaster::CmdResult RomCommands::OWSkipRom(OneWireMaster & owMaster)
+{
+    OneWireMaster::CmdResult result;
+
+    result = owMaster.OWReset();
+    if (result == OneWireMaster::Success)
+    {
+        result = owMaster.OWWriteByte(SkipRomCmd);
+    }
+
+    return result;
+}
+  
+OneWireMaster::CmdResult RomCommands::OWMatchRom(OneWireMaster & owMaster, const RomId & romId)
+{
+    OneWireMaster::CmdResult result;
+
+    uint8_t buf[1 + RomId::byteLen];
+
+    // use MatchROM
+    result = owMaster.OWReset();
+    if (result == OneWireMaster::Success)
+    {
+        buf[0] = MatchRomCmd;
+        std::memcpy(&buf[1], romId, RomId::byteLen);
+        // send command and rom
+        result = owMaster.OWWriteBlock(buf, 1 + RomId::byteLen);
+    }
+
+    return result;
+}
+  
+OneWireMaster::CmdResult RomCommands::OWOverdriveSkipRom(OneWireMaster & owMaster)
+{
+    OneWireMaster::CmdResult result = owMaster.OWSetSpeed(OneWireMaster::StandardSpeed);
+
+    if (result == OneWireMaster::Success)
+    {
+        result = owMaster.OWReset();
+    }
+
+    if (result == OneWireMaster::Success)
+    {
+        result = owMaster.OWWriteByte(OverdriveSkipRomCmd);
+    }
+
+    if (result == OneWireMaster::Success)
+    {
+        result = owMaster.OWSetSpeed(OneWireMaster::OverdriveSpeed);
+    }
+
+    return result;
+}
+  
+OneWireMaster::CmdResult RomCommands::OWOverdriveMatchRom(OneWireMaster & owMaster, const RomId & romId)
+{
+    OneWireMaster::CmdResult result;
+
+    // use overdrive MatchROM
+    owMaster.OWSetSpeed(OneWireMaster::StandardSpeed);
+
+    result = owMaster.OWReset();
+    if (result == OneWireMaster::Success)
+    {
+        result = owMaster.OWWriteByte(OverdriveMatchRomCmd);
+        if (result == OneWireMaster::Success)
+        {
+            owMaster.OWSetSpeed(OneWireMaster::OverdriveSpeed);
+            // send ROM
+            result = owMaster.OWWriteBlock(romId, RomId::byteLen);
+        }
+    }
+    return result;
+}
+   
+OneWireMaster::CmdResult RomCommands::OWResume(OneWireMaster & owMaster)
+{
+    OneWireMaster::CmdResult result;
+
+    result = owMaster.OWReset();
+    if (result == OneWireMaster::Success)
+    {
+        result = owMaster.OWWriteByte(ResumeCmd);
+    }
+
+    return result;
+}
+
+OneWireMaster::CmdResult RomCommands::OWSearch(OneWireMaster & owMaster, SearchState & searchState)
+{
+    uint8_t id_bit_number;
+    uint8_t last_zero, rom_byte_number;
+    uint8_t id_bit, cmp_id_bit;
+    uint8_t rom_byte_mask;
+    bool search_result;
+    uint8_t crc8 = 0;
+    OneWireMaster::SearchDirection search_direction;
+
+    // initialize for search
+    id_bit_number = 1;
+    last_zero = 0;
+    rom_byte_number = 0;
+    rom_byte_mask = 1;
+    search_result = false;
+
+    // if the last call was not the last one
+    if (!searchState.last_device_flag)
+    {
+        // 1-Wire reset
+        OneWireMaster::CmdResult result = owMaster.OWReset();
+        if (result != OneWireMaster::Success)
+        {
+            // reset the search
+            searchState.reset();
+            return result;
+        }
+
+        // issue the search command 
+        owMaster.OWWriteByte(SearchRomCmd);
+
+        // loop to do the search
+        do
+        {
+            // if this discrepancy if before the Last Discrepancy
+            // on a previous next then pick the same as last time
+            if (id_bit_number < searchState.last_discrepancy)
+            {
+                if ((searchState.romId[rom_byte_number] & rom_byte_mask) > 0)
+                {
+                    search_direction = OneWireMaster::WriteOne;
+                }
+                else
+                {
+                    search_direction = OneWireMaster::WriteZero;
+                }
+            }
+            else
+            {
+                // if equal to last pick 1, if not then pick 0
+                if (id_bit_number == searchState.last_discrepancy)
+                {
+                    search_direction = OneWireMaster::WriteOne;
+                }
+                else
+                {
+                    search_direction = OneWireMaster::WriteZero;
+                }
+            }
+
+            // Peform a triple operation on the DS2465 which will perform 2 read bits and 1 write bit
+            result = owMaster.OWTriplet(search_direction, id_bit, cmp_id_bit);
+            if (result != OneWireMaster::Success)
+            {
+                return result;
+            }
+
+            // check for no devices on 1-wire
+            if (id_bit && cmp_id_bit)
+            {
+                break;
+            }
+            else
+            {
+                if (!id_bit && !cmp_id_bit && (search_direction == OneWireMaster::WriteZero))
+                {
+                    last_zero = id_bit_number;
+
+                    // check for Last discrepancy in family
+                    if (last_zero < 9)
+                    {
+                        searchState.last_family_discrepancy = last_zero;
+                    }
+                }
+
+                // set or clear the bit in the ROM byte rom_byte_number
+                // with mask rom_byte_mask
+                if (search_direction == OneWireMaster::WriteOne)
+                {
+                    searchState.romId[rom_byte_number] |= rom_byte_mask;
+                }
+                else
+                {
+                    searchState.romId[rom_byte_number] &= (uint8_t)~rom_byte_mask;
+                }
+
+                // increment the byte counter id_bit_number
+                // and shift the mask rom_byte_mask
+                id_bit_number++;
+                rom_byte_mask <<= 1;
+
+                // if the mask is 0 then go to new SerialNum byte rom_byte_number and reset mask
+                if (rom_byte_mask == 0)
+                {
+                    crc8 = RomId::calculateCrc8(crc8, searchState.romId[rom_byte_number]);  // accumulate the CRC
+                    rom_byte_number++;
+                    rom_byte_mask = 1;
+                }
+            }
+        } while (rom_byte_number < RomId::byteLen);  // loop until through all ROM bytes 0-7
+
+        // if the search was successful then
+        if (!((id_bit_number <= (RomId::byteLen * 8)) || (crc8 != 0)))
+        {
+            // search successful so set m_last_discrepancy,m_last_device_flag,search_result
+            searchState.last_discrepancy = last_zero;
+
+            // check for last device
+            if (searchState.last_discrepancy == 0)
+            {
+                searchState.last_device_flag = true;
+            }
+
+            search_result = true;
+        }
+    }
+
+    // if no device found then reset counters so next 'search' will be like a first
+    if (!search_result || (searchState.romId.familyCode() == 0))
+    {
+        searchState.reset();
+        search_result = false;
+    }
+
+    return (search_result ? OneWireMaster::Success : OneWireMaster::OperationFailure);
+}