Implementation of 1-Wire with added Alarm Search Functionality
Dependents: Max32630_One_Wire_Interface
OneWire_Masters/OneWireMaster.cpp
- Committer:
- IanBenzMaxim
- Date:
- 2016-05-09
- Revision:
- 71:562f5c702094
- Parent:
- 57:1635f247ceae
File content as of revision 71:562f5c702094:
/******************************************************************//** * Copyright (C) 2016 Maxim Integrated Products, Inc., All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice shall be included * in all copies or substantial portions of the Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR * OTHER DEALINGS IN THE SOFTWARE. * * Except as contained in this notice, the name of Maxim Integrated * Products, Inc. shall not be used except as stated in the Maxim Integrated * Products, Inc. Branding Policy. * * The mere transfer of this software does not imply any licenses * of trade secrets, proprietary technology, copyrights, patents, * trademarks, maskwork rights, or any other form of intellectual * property whatsoever. Maxim Integrated Products, Inc. retains all * ownership rights. **********************************************************************/ #include "OneWireMaster.h" #include "RomId.hpp" using namespace std; enum OW_ROM_CMD { READ_ROM = 0x33, MATCH_ROM = 0x55, SEARCH_ROM = 0xF0, SKIP_ROM = 0xCC, RESUME = 0xA5, OVERDRIVE_SKIP_ROM = 0x3C, OVERDRIVE_MATCH_ROM = 0x69 }; //********************************************************************* OneWireMaster::CmdResult OneWireMaster::OWWriteBlock(const uint8_t *tran_buf, uint8_t tran_len) { CmdResult result; for(uint8_t idx = 0; idx < tran_len; idx++) { result = OWWriteByte(tran_buf[idx]); if(result != Success) { break; } } return result; } //********************************************************************* OneWireMaster::CmdResult OneWireMaster::OWReadBlock(uint8_t *rx_buf, uint8_t rx_len) { CmdResult result; for(uint8_t idx = 0; idx < rx_len; idx++) { result = OWReadByte(rx_buf[idx]); if(result != Success) { break; } } return result; } OneWireMaster::CmdResult OneWireMaster::OWFirst(SearchState & searchState) { // reset the search state searchState.reset(); return OWSearch(searchState); } //********************************************************************* OneWireMaster::CmdResult OneWireMaster::OWNext(SearchState & searchState) { // leave the search state alone return OWSearch(searchState); } //********************************************************************* OneWireMaster::CmdResult OneWireMaster::OWVerify(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(searchState); if (result == OneWireMaster::Success) { // check if same device found if (romId != searchState.romId) { result = OneWireMaster::OperationFailure; } } return result; } //********************************************************************* void OneWireMaster::OWTargetSetup(SearchState & searchState) { // set the search state to find SearchFamily type devices std::uint8_t familyCode = searchState.romId.familyCode(); searchState.reset(); searchState.romId.setFamilyCode(familyCode); searchState.last_discrepancy = 64; } //********************************************************************* void OneWireMaster::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 OneWireMaster::OWReadROM(RomId & romId) { OneWireMaster::CmdResult result; uint8_t buf[2 + RomId::byteLen]; result = OWReset(); if (result == OneWireMaster::Success) { result = OWWriteByte(READ_ROM); } // read the ROM if (result == OneWireMaster::Success) { result = OWReadBlock(buf, RomId::byteLen); } // verify CRC8 if ((result == OneWireMaster::Success) && (RomId::calculateCRC8(buf, RomId::byteLen) == 0)) { romId = RomId(reinterpret_cast<std::uint8_t (&)[RomId::byteLen]>(buf[0])); } return result; } //********************************************************************* OneWireMaster::CmdResult OneWireMaster::OWSkipROM(void) { OneWireMaster::CmdResult result; result = OWReset(); if (result == OneWireMaster::Success) { result = OWWriteByte(SKIP_ROM); } return result; } //********************************************************************* OneWireMaster::CmdResult OneWireMaster::OWMatchROM(const RomId & romId) { OneWireMaster::CmdResult result; uint8_t buf[1 + RomId::byteLen]; // use MatchROM result = OWReset(); if (result == OneWireMaster::Success) { buf[0] = MATCH_ROM; std::memcpy(&buf[1], romId, RomId::byteLen); // send command and rom result = OWWriteBlock(buf, 1 + RomId::byteLen); } return result; } //********************************************************************* OneWireMaster::CmdResult OneWireMaster::OWOverdriveSkipROM(void) { OneWireMaster::CmdResult result = OWSetSpeed(SPEED_STANDARD); if (result == OneWireMaster::Success) { result = OWReset(); } if (result == OneWireMaster::Success) { result = OWWriteByte(OVERDRIVE_SKIP_ROM); } if (result == OneWireMaster::Success) { result = OWSetSpeed(SPEED_OVERDRIVE); } return result; } //********************************************************************* OneWireMaster::CmdResult OneWireMaster::OWOverdriveMatchROM(const RomId & romId) { OneWireMaster::CmdResult result; // use overdrive MatchROM OWSetSpeed(SPEED_STANDARD); result = OWReset(); if (result == OneWireMaster::Success) { result = OWWriteByte(OVERDRIVE_MATCH_ROM); if (result == OneWireMaster::Success) { OWSetSpeed(SPEED_OVERDRIVE); // send ROM result = OWWriteBlock(romId, RomId::byteLen); } } return result; } //********************************************************************* OneWireMaster::CmdResult OneWireMaster::OWResume(void) { OneWireMaster::CmdResult result; result = OWReset(); if (result == OneWireMaster::Success) { result = OWWriteByte(RESUME); } return result; } OneWireMaster::CmdResult OneWireMaster::OWSearch(SearchState & searchState) { std::uint8_t id_bit_number; std::uint8_t last_zero, rom_byte_number; std::uint8_t id_bit, cmp_id_bit; std::uint8_t rom_byte_mask; bool search_result; std::uint8_t crc8 = 0; 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 = OWReset(); if (result != OneWireMaster::Success) { // reset the search searchState.reset(); return result; } // issue the search command OneWireMaster::OWWriteByte(SEARCH_ROM); // 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 = DIRECTION_WRITE_ONE; else search_direction = DIRECTION_WRITE_ZERO; } else { // if equal to last pick 1, if not then pick 0 if (id_bit_number == searchState.last_discrepancy) search_direction = DIRECTION_WRITE_ONE; else search_direction = DIRECTION_WRITE_ZERO; } // Peform a triple operation on the DS2465 which will perform 2 read bits and 1 write bit result = 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 == DIRECTION_WRITE_ZERO)) { 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 == DIRECTION_WRITE_ONE) searchState.romId[rom_byte_number] |= rom_byte_mask; else searchState.romId[rom_byte_number] &= (std::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; } OneWireMaster::CmdResult OneWireMaster::OWTriplet(SearchDirection & search_direction, std::uint8_t & sbr, std::uint8_t & tsb) { CmdResult result; result = OWReadBit(sbr); if (result == Success) result = OWReadBit(tsb); if (result == Success) { if (sbr) search_direction = DIRECTION_WRITE_ONE; else if (tsb) search_direction = DIRECTION_WRITE_ZERO; // else: use search_direction parameter result = OWWriteBit((search_direction == DIRECTION_WRITE_ONE) ? 1 : 0); } return result; } uint16_t OneWireMaster::calculateCRC16(uint16_t CRC16, uint16_t data) { const uint16_t _oddparity[] = { 0, 1, 1, 0, 1, 0, 0, 1, 1, 0, 0, 1, 0, 1, 1, 0 }; data = (data ^ (CRC16 & 0xff)) & 0xff; CRC16 >>= 8; if (_oddparity[data & 0xf] ^ _oddparity[data >> 4]) CRC16 ^= 0xc001; data <<= 6; CRC16 ^= data; data <<= 1; CRC16 ^= data; return CRC16; } uint16_t OneWireMaster::calculateCRC16(const uint8_t * data, size_t data_offset, size_t data_len, uint16_t crc) { for (size_t i = data_offset; i < (data_len + data_offset); i++) crc = calculateCRC16(crc, data[i]); return crc; }