An experimental timer interrupt driven software based 1-Wire master interface that was created by Robert David Brinzer for a University of Glasgow Level 4 Electronic and Software Engineering Final Year project. This implementation requires mbed RTOS and does not use NOP waits. Perfect for programs that require multi-tasking. Includes the Read and Search network commands and can be easily extended to support new network and transport commands.
Diff: Instructions/Transport.h
- Revision:
- 0:7c6dd6bc20e4
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/Instructions/Transport.h Mon Apr 15 07:02:49 2013 +0000 @@ -0,0 +1,86 @@ +#ifndef ROM_COMMANDS +#define ROM_COMMANDS + +#include "OneWire.h" + +class ROMCommands; + +#define READ_ROM 0x33 +#define SKIP_ROM 0xCC +#define MATCH_ROM 0x55 +#define SEARCH_ROM 0xF0 + +// type used to represent a one-wire rom code +typedef unsigned long long OneWire_ROM; + +// types used for the one-wire registers +typedef struct TransportRead{ + unsigned char read; // bits or rom read + unsigned char crc8; // crc8 check +} TransportRead; + +/** Persistant search structure + * Used to keep track of search state and results between executions of the search transport layer command + */ +typedef struct TransportSearchPersist{ + /** Rom code result of previous search operation + * + * @note value should be ignored if a one-wire execution error occured + */ + OneWire_ROM rom; + + signed char last; // used internally by the micro instruction system to keep track of state + + /** Used to tell when to end a search sequence + * + * TRUE when the search has completed + * + * FALSE when there are still rom codes left to search + */ + bool done; + + /** Clears existing search state and results in preparation for a new search + * + * This will reset search progress to start a search sequence from the beginning + * + * @note Search sequences should be restarted if a one-wire execution error occured as persistant state values might be invalid + */ + void clear(); +} TransportSearchPersist; + +typedef struct TransportSearch{ + unsigned char read; // bits or rom read + unsigned char crc8; // crc8 check + signed char marker; // last conflict marker + unsigned char bit; // storage place current bit result +} TransportSearch; + +/** One-Wire Transport layer class + * Used to set up a one-wire instruction with a transport layer + */ +class OWTransport{ +public: + /** Set a one-wire instruction to perform the read transport layer command + * + * @param inst One-wire instruction that will carry out the command + * @param out One-wire rom that will be used to store the read rom code + */ + static void read(OneWire_Instruction * inst, OneWire_ROM * out); + + /** Set a one-wire instruction to perform the search transport layer command + * + * @param inst One-wire instruction that will carry out the command + * @param search Persistant search structure that will be used for search state and results + */ + static void search(OneWire_Instruction * inst, TransportSearchPersist * search); +private: + // private functions which carry out the one-wire logic + static void _inst_readsetup(OneWire * which); + static void _inst_read(OneWire * which); + static void _inst_readhandler(OneWire * which, char bit); + static void _inst_searchsetup(OneWire * which); + static void _inst_search(OneWire * which); + static void _inst_searchhandler(OneWire * which, char bit); +}; + +#endif \ No newline at end of file