RomCommands.hpp

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00032 
00033 /// @file
00034 /// @brief ROM Commands for enumerating and selecting 1-Wire devices.
00035 
00036 #ifndef MaximInterfaceCore_RomCommands_hpp
00037 #define MaximInterfaceCore_RomCommands_hpp
00038 
00039 #include <stdint.h>
00040 #include "Algorithm.hpp"
00041 #include "Config.hpp"
00042 #include "OneWireMaster.hpp"
00043 #include "RomId.hpp"
00044 
00045 namespace MaximInterfaceCore {
00046 
00047 /// State used by Search ROM command.
00048 struct SearchRomState {
00049   RomId::array romId;
00050   int_least8_t lastDiscrepancy;
00051   int_least8_t lastFamilyDiscrepancy;
00052   bool lastDevice;
00053 
00054   SearchRomState()
00055       : romId(), lastDiscrepancy(0), lastFamilyDiscrepancy(0),
00056         lastDevice(false) {}
00057 
00058   explicit SearchRomState(RomId::const_span romId)
00059       : lastDiscrepancy(64), lastFamilyDiscrepancy(0), lastDevice(false) {
00060     copy(romId, make_span(this->romId));
00061   }
00062 
00063   explicit SearchRomState(RomId::element familyCode)
00064       : romId(), lastDiscrepancy(64), lastFamilyDiscrepancy(0),
00065         lastDevice(false) {
00066     romId.front() = familyCode;
00067   }
00068 };
00069 
00070 /// @brief
00071 /// Set the search state to skip the current device family on the next
00072 /// Search ROM command.
00073 MaximInterfaceCore_EXPORT void skipCurrentFamily(SearchRomState & searchState);
00074 
00075 /// Verify that the device with the specified ROM ID is present.
00076 MaximInterfaceCore_EXPORT Result<void> verifyRom(OneWireMaster & master,
00077                                                  RomId::const_span romId);
00078 
00079 /// @brief Use Read ROM command to read ROM ID from device on bus.
00080 /// @note
00081 /// Only use this command with a single-drop bus.
00082 /// Data collisions will occur if there is more than one device on the bus.
00083 /// @param master 1-Wire master for operation.
00084 /// @returns ROM ID read from device.
00085 MaximInterfaceCore_EXPORT Result<RomId::array> readRom(OneWireMaster & master);
00086 
00087 /// @brief Issue Skip ROM command on bus.
00088 /// @note
00089 /// Only use this command with a single-drop bus.
00090 /// Data collisions will occur if there is more than one device on the bus.
00091 MaximInterfaceCore_EXPORT Result<void> skipRom(OneWireMaster & master);
00092 
00093 /// @brief Use the Match ROM command to select the device by its known ID.
00094 /// @note
00095 /// This command causes all devices supporting Overdrive mode to switch to
00096 /// Overdrive timing.
00097 /// @param master 1-Wire master for operation.
00098 /// @param[in] romId ROM ID of device to select.
00099 MaximInterfaceCore_EXPORT Result<void> matchRom(OneWireMaster & master,
00100                                                 RomId::const_span romId);
00101 
00102 /// @brief Issue Overdrive Skip ROM command on bus.
00103 /// @note
00104 /// This command causes all devices supporting Overdrive mode to switch to
00105 /// Overdrive timing.
00106 /// @note
00107 /// Only use this command with a single-drop bus.
00108 /// Data collisions will occur if there is more than one device on the bus.
00109 MaximInterfaceCore_EXPORT Result<void> overdriveSkipRom(OneWireMaster & master);
00110 
00111 /// @brief
00112 /// Use the Overdrive Match ROM command to select the device by its known ID.
00113 /// @param master 1-Wire master for operation.
00114 /// @param[in] romId ROM ID of device to select.
00115 MaximInterfaceCore_EXPORT Result<void>
00116 overdriveMatchRom(OneWireMaster & master, RomId::const_span romId);
00117 
00118 /// @brief Perform a Resume ROM command on bus.
00119 /// @details
00120 /// Resumes communication with the last device selected through a Match ROM or
00121 /// Search ROM operation.
00122 MaximInterfaceCore_EXPORT Result<void> resumeRom(OneWireMaster & master);
00123 
00124 /// @brief Find device on the 1-Wire bus.
00125 /// @details
00126 /// This command uses the Search ROM command to enumerate all 1-Wire devices in
00127 /// sequence. Begin with a new search state and continue using the same search
00128 /// state until the last device flag is set which indicates that all devices
00129 /// have been discovered.
00130 MaximInterfaceCore_EXPORT Result<void> searchRom(OneWireMaster & master,
00131                                                  SearchRomState & searchState);
00132 
00133 } // namespace MaximInterfaceCore
00134 
00135 #endif