/***************************************************************************** * Function name : DS18B20_SetDeviceAccuracy * Parameters : bus - вывод микроконтроллера, который выполн¤ет роль 1WIRE шины * *id - им¤ массива из 8-ми элементов, в котором хранитс¤ * адрес датчика DS18B20 * accuracy - значение точность необходимой дл¤ установлени¤ * 0 - 9bit * 1 - 10bit * 2 - 11bit * 3 - 12bit * * Purpose : јдресует датчик DS18B20, записывает в пам¤ть (scratchpad), * копирует scratchpad в EEPROM. * —ледует вызывать только один раз дл¤ настройки устройства *****************************************************************************/ void DS18B20_SetDeviceAccuracy(unsigned char bus, unsigned char* id, unsigned char accuracy){ OWI_DetectPresence(bus); OWI_MatchRom(id, bus); OWI_SendByte(DS18B20_WRITE_SCRATCHPAD, bus); OWI_SendByte(0x00, bus); //Th OWI_SendByte(0x00, bus); //Tl OWI_SendByte(0x1F | ((accuracy & 0x03)<<5), bus); //Config OWI_DetectPresence(bus); OWI_MatchRom(id, bus); OWI_SendByte(DS18B20_COPY_SCRATCHPAD, bus); while (!OWI_ReadBit(bus)); }
*/ uint16_t ReadDualSwitches( unsigned char bus_pattern, unsigned char * id ) { uint16_t value = 0x0; // continue if bus isn't active if ( 0 == ( ( owiBusMask & bus_pattern ) & 0xFF ) ) { return owiReadStatus_owi_bus_mismatch << 8; } // continue if bus doesn't contain any Dual Switches if ( 0 == ( ( owiDualSwitchMask & bus_pattern ) & 0xFF ) ) { return owiReadStatus_owi_bus_mismatch << 8; } /* Reset, presence.*/ if ( OWI_DetectPresence(bus_pattern) == 0 ) { return owiReadStatus_no_device_presence << 8; } OWI_MatchRom(id, bus_pattern); /* Match id found earlier*/ OWI_SendByte(DS2413_PIO_ACCESS_READ, bus_pattern); //PIO Access read command /*Read first byte and place them in the 16 bit channel variable*/ value = OWI_ReceiveByte(bus_pattern); value &= 0xFF; OWI_DetectPresence(bus_pattern); /* generate RESET to stop slave sending its status and presence pulse*/ return value | owiReadWriteStatus_OK << 8;
/***************************************************************************** * Function name : DS18B20_ReadDevice * Returns : коды - READ_CRC_ERROR, если считанные данные не прошли проверку * READ_SUCCESSFUL, если данные прошли проверку * Parameters : bus - вывод микроконтроллера, который выполн¤ет роль 1WIRE шины * *id - им¤ массива из 8-ми элементов, в котором хранитс¤ * адрес датчика DS18B20 * *temperature - указатель на шестнадцати разр¤дную переменную * в которой будет сохранено считанного зн. температуры * Purpose : ћетод только считывает значение ”∆≈ »«ћ≈–≈ЌЌќ… температуры из scratchpad, * Ќ≈ ¬џѕќЋЌя≈“ »«ћ≈–≈Ќ»≈ * јдресует датчик DS18B20, считывает его пам¤ть - scratchpad, провер¤ет CRC, * сохран¤ет значение температуры в переменной, возвращает код ошибки *****************************************************************************/ unsigned char DS18B20_ReadDevice(unsigned char bus, unsigned char* id, signed int* temperature){ unsigned char scratchpad[9]; OWI_DetectPresence(bus); OWI_MatchRom(id, bus); OWI_SendByte(DS18B20_READ_SCRATCHPAD, bus); for (unsigned char i = 0; i <= 8; i++){ scratchpad[i] = OWI_ReceiveByte(bus); } if(OWI_CheckScratchPadCRC(scratchpad) != OWI_CRC_OK){ return READ_CRC_ERROR; } *temperature = (unsigned int)scratchpad[0]; *temperature |= ((unsigned int)scratchpad[1] << 8); if ((*temperature & 0x8000) != 0){ *temperature = -(~(*temperature) + 1); } //*temperature *= 0.625f; *temperature *= 5; //0.625 = 5/8 *temperature /= 8; return READ_SUCCESSFUL; }
/***************************************************************************** * Function name : DS18B20_StartDeviceConvertingAndRead * Returns : коды - READ_CRC_ERROR, если считанные данные не прошли проверку * READ_SUCCESSFUL, если данные прошли проверку * Parameters : bus - вывод микроконтроллера, который выполн¤ет роль 1WIRE шины * *id - им¤ массива из 8-ми элементов, в котором хранитс¤ * адрес датчика DS18B20 * *temperature - указатель на шестнадцати разр¤дную переменную * в которой будет сохранено считанного зн. температуры * Purpose : ¬џѕќЋЌя≈“ »«ћ≈–≈Ќ»≈ » ¬ќ«¬–јўј≈“ «Ќј„≈Ќ»≈ “≈ћѕ≈–ј“”–џ * јдресует датчик DS18B20, дает команду на преобразование температуры * ждет, считывает его пам¤ть - scratchpad, провер¤ет CRC, * сохран¤ет значение температуры в переменной, возвращает код ошибки *****************************************************************************/ unsigned char DS18B20_StartDeviceConvertingAndRead(unsigned char bus, unsigned char* id, signed int* temperature){ OWI_DetectPresence(bus); OWI_MatchRom(id, bus); OWI_SendByte(DS18B20_CONVERT_T, bus); /*ждем, когда датчик завершит преобразование*/ //while (!OWI_ReadBit(bus)); _delay_ms(750); return DS18B20_ReadDevice(bus, id, temperature); }
/***************************************************************************** * Function name : DS18B20_ReadTemperature * Returns : коды - READ_CRC_ERROR, если считанные данные не прошли проверку * READ_SUCCESSFUL, если данные прошли проверку * Parameters : bus - вывод микроконтроллера, который выполняет роль 1WIRE шины * *id - имя массива из 8-ми элементов, в котором хранится * адрес датчика DS18B20 * *ds18b20_temperature - указатель на шестнадцати разрядную переменную * в которой будет сохранено считанного зн. температуры * Purpose : Адресует датчик DS18B20, дает команду на преобразование температуры * ждет, считывает его память - scratchpad, проверяет CRC, * сохраняет значение температуры в переменной, возвращает код ошибки *****************************************************************************/ BYTE DS18B20_ReadTemperature(BYTE bus, BYTE * id, WORD* ds18b20_temperature) { unsigned char scratchpad[9]; unsigned char i; /*подаем сигнал сброса команду для адресации устройства на шине подаем команду - запук преобразования */ OWI_DetectPresence(bus); OWI_MatchRom(id, bus); OWI_SendByte(DS18B20_CONVERT_T ,bus); /*ждем, когда датчик завершит преобразование*/ while (!OWI_ReadBit(bus)); /*подаем сигнал сброса команду для адресации устройства на шине команду - чтение внутренней памяти затем считываем внутреннюю память датчика в массив */ OWI_DetectPresence(bus); OWI_MatchRom(id, bus); OWI_SendByte(DS18B20_READ_SCRATCHPAD, bus); for (i = 0; i<=8; i++){ scratchpad[i] = OWI_ReceiveByte(bus); } if(OWI_CheckScratchPadCRC(scratchpad) != OWI_CRC_OK){ return READ_CRC_ERROR; } *ds18b20_temperature = MAKEWORD(scratchpad[0], scratchpad[1]); return READ_SUCCESSFUL; }
/* *this function writes the state of dual switch */ uint16_t WriteDualSwitches( unsigned char bus_pattern, unsigned char * id, uint8_t value ) { static unsigned char timeout_flag; static uint32_t count; static uint8_t status; static uint32_t maxcount = OWI_DUAL_SWITCHES_MAXIMUM_WRITE_ACCESS_COUNTS; // continue if bus isn't active if ( 0 == ( ( owiBusMask & bus_pattern ) & 0xFF ) ) { return owiReadStatus_owi_bus_mismatch << 8; } // continue if bus doesn't contain any Dual Switches if ( 0 == ( ( owiDualSwitchMask & bus_pattern ) & 0xFF ) ) { return owiReadStatus_owi_bus_mismatch << 8; } /* Reset, presence.*/ if ( OWI_DetectPresence(bus_pattern) == 0 ) { return owiReadStatus_no_device_presence << 8; } count = maxcount; timeout_flag = FALSE; status = 0; /* Match id found earlier*/ OWI_MatchRom(id, bus_pattern); /* PIO Access write command */ OWI_SendByte(DS2413_PIO_ACCESS_WRITE, bus_pattern); /* loop writing value and its complement, and waiting for confirmation */ while (DS2413_WRITE_CONFIRMATION_PATTERN != status ) { status = 0; /* timeout check */ if ( 0 == --count) { timeout_flag = TRUE; break; } OWI_SendByte( (value |= 0xFC ), bus_pattern); // write value 0:on 1:off OWI_SendByte(~(value |= 0xFC ), bus_pattern); // to confirm, write inverted /*Read status */ status = OWI_ReceiveByte(bus_pattern); status &= 0xFF; } if ( FALSE == timeout_flag ) { /*Read first byte*/ value = OWI_ReceiveByte(bus_pattern); value &= 0xFF; OWI_DetectPresence(bus_pattern); /* generate RESET to stop slave sending its status and presence pulse*/ return value | owiReadWriteStatus_OK << 8; } else { OWI_DetectPresence(bus_pattern); /* generate RESET to stop slave sending its status and presence pulse*/ CommunicationError_p(ERRG, dynamicMessage_ErrorIndex, TRUE, PSTR("OWI Dual Switch write value timeout")); return value | owiWriteStatus_Timeout << 8; } return value | owiReadWriteStatus_OK << 8;
/* *this function gets the ADC-value of all channels of one device */ uint32_t owiReadChannelsOfSingleADCs( unsigned char bus_pattern, unsigned char * id, uint16_t *array_chn, const int8_t size ) { static const uint8_t maxTrials = 3; uint8_t channelIndex = 0; uint16_t CRC; uint8_t flag = FALSE; uint8_t trialsCounter = maxTrials; uint32_t returnValue; uint8_t loopTurn = 0; uint16_t channelArray[DS2450_TRIPLE_CONVERSION_MAX_LOOP_TURN][4]; uint8_t maxLoopTurn; /* 0 trials, give it a chance */ if (0 == trialsCounter) { trialsCounter++;} if (TRUE == owiAdcTripleReadout) { maxLoopTurn = DS2450_TRIPLE_CONVERSION_MAX_LOOP_TURN; } else { maxLoopTurn = 1; } /*checks*/ printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("begin")); if ( 0 == ((owiBusMask & bus_pattern) & 0xFF) ) { printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("passive (bus pattern %#x owiBusMask %#x)"), bus_pattern,owiBusMask); return ((uint32_t) owiReadStatus_owi_bus_mismatch) << OWI_ADC_DS2450_MAX_RESOLUTION; } if ( 0 != ((owiAdcTimeoutAndFailureBusMask & bus_pattern) & 0xFF) ) { //conversion went into timeout owiCreateIdString(owi_id_string, id); CommunicationError_p(ERRG, dynamicMessage_ErrorIndex, TRUE, PSTR("OWI ADC Conversion Error id: %s (bus_pattern %#x)"), owi_id_string, bus_pattern); return ((uint32_t) owiReadStatus_conversion_timeout) << OWI_ADC_DS2450_MAX_RESOLUTION; } #warning TODO: consider the case that bus_pattern has more than one bit active, but the conversion failed/succeeded not on all the same way for ( loopTurn = 0; loopTurn < maxLoopTurn; loopTurn++) { /* Reset, presence */ if ( 0 == OWI_DetectPresence(bus_pattern) ) { return ((uint32_t) owiReadStatus_no_device_presence) << OWI_ADC_DS2450_MAX_RESOLUTION; // Error } /* Send READ MEMORY command * * READ MEMORY [AAH] * * The Read Memory command is used to read conversion results, control/status data and alarm settings. * The bus master follows the command byte with a two byte address (TA1=(T7:T0), TA2=(T15:T8)) that * indicates a starting byte location within the memory map. * * With every subsequent read data time slot the bus master receives data from the DS2450 * starting at the supplied address and continuing until the end of * an eight-byte page is reached. At that point the bus master will receive a 16-bit CRC of the command byte, * address bytes and data bytes. This CRC is computed by the DS2450 and read back by the bus master to check * if the command word, starting address and data were received correctly. If the CRC read by the bus master * is incorrect, a Reset Pulse must be issued and the entire sequence must be repeated. * * Note that the initial pass through the Read Memory flow chart will generate a 16-bit CRC value that is the * result of clearing the CRC-generator and then shifting in the command byte followed by the two address * bytes, and finally the data bytes beginning at the first addressed memory location and continuing through * to the last byte of the addressed page. Subsequent passes through the Read Memory flow chart will * generate a 16-bit CRC that is the result of clearing the CRC-generator and then shifting in the new data * bytes starting at the first byte of the next page. * * (http://datasheets.maximintegrated.com/en/ds/DS2450.pdf) * */ while ( FALSE == flag && trialsCounter != 0) { /* Match id found earlier*/ OWI_MatchRom(id, bus_pattern); // Match id found earlier #warning TODO: is the CRC check described above done here? if this sequence is repeated implement a timeout counter OWI_SendByte(DS2450_READ_MEMORY, bus_pattern); /* set starting address for memory read */ OWI_SendWord(DS2450_ADDRESS_MEMORY_MAP_PAGE_0_CONVERSION_READOUT_INPUT_A_LSB, bus_pattern); //Send two bytes address (ie: 0x00 & 0x00,0x08 & 0x00,0x10 & 0x00,0x18 & 0x00) for (channelIndex = 0; channelIndex < 4; channelIndex++) { // Read a word place it in the 16 bit channel variable. channelArray[loopTurn][channelIndex] = OWI_ReceiveWord(bus_pattern); } /* Receive CRC */ CRC = OWI_ReceiveWord(bus_pattern); /* Check CRC */ flag = TRUE; /*Pseudo check*/ #if 0 if ( checkCRC(...)) { flag = TRUE; } else { trialsCounter--; OWI_DetectPresence(bus_pattern); } #endif } OWI_DetectPresence(bus_pattern); if (FALSE == flag) /*error*/ { returnValue = ((uint32_t) 1 ) | (((uint32_t)owiReadWriteStatus_MAXIMUM_INDEX) << OWI_ADC_DS2450_MAX_RESOLUTION); break; } /*re-convert channel*/ // owiADCConvert(bus_pattern, id); owiADCConvert(bus_pattern, 0); } if ( TRUE == flag ) { clearString_p(resultString, BUFFER_SIZE); int32_t a, b, c; uint32_t m=0; char value[7]; for (uint8_t channel = 0; channel < 4; channel++ ) { if ( FALSE == owiAdcTripleReadout ) { m = channelArray[0][channel]; } else /*triple readout, take the average of the two closest values*/ { a = channelArray[0][channel]; b = channelArray[1][channel]; c = channelArray[2][channel]; if ( abs(a-b) <= abs(a-c) ) { if ( abs(a-b) <= abs(b-c) ) { m = (a+b)/2; } else { m = (b+c)/2; } } else { if ( abs(a-c) <= abs(b-c) ) { m = (a+c)/2; } else { m = (b+c)/2; } } } snprintf(value, 7 - 1, " %.4lX", m); strncat(resultString, value, BUFFER_SIZE - 1); } if ( TRUE == owiAdcTripleReadout) { for ( loopTurn = 0; loopTurn < DS2450_TRIPLE_CONVERSION_MAX_LOOP_TURN; loopTurn++) { for (uint8_t channel = 0; channel < 4; channel++ ) { snprintf(value, 7 - 1, " %.4X", channelArray[loopTurn][channel]); strncat(resultString, value, BUFFER_SIZE - 1); } } } printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("retrieved data and end")); returnValue = ((uint32_t) 0 ) | (((uint32_t)owiReadWriteStatus_OK) << OWI_ADC_DS2450_MAX_RESOLUTION); } return returnValue; }//END of owiReadChannelsOfSingleADCs function
/* * owiADCConvert(unsigned char bus_pattern, unsigned char * id) * * * this function implements the convert function * using the 0x3C command * * CRC checks are not performed * * input: * bus_pattern: * pattern of bus lines to send command to * id : * 1-wire device id 8 byte char array * - if set, i.e. not NULL, only device with this id is addressed (MATCH_ROM) * - else every device is used (ROM_SKIP) * * return: * 0: ok * 1: failed * */ uint8_t owiADCConvert(unsigned char currentPins, unsigned char * id) { printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("bus_pattern: %#x starting conversion sequence"), currentPins ); static uint16_t maxConversionTime = OWI_ADC_MAX_CONVERSION_TIME_MILLISECONDS; static uint32_t count; static uint32_t maxcount; static unsigned char timeout_flag; uint8_t trialsCounter = 0; uint8_t result = RESULT_OK; uint16_t receive_CRC; maxcount = ( OWI_ADC_CONVERSION_DELAY_MILLISECONDS > 0 ) ? maxConversionTime / OWI_ADC_CONVERSION_DELAY_MILLISECONDS : 1; count = maxcount; timeout_flag = FALSE; /* * CONVERT [3CH] * * The Convert command is used to initiate the analog to digital conversion for one or more channels at the * resolution specified in memory page 1, control/status data. The conversion takes between 60 and 80 μs * per bit plus an offset time of maximum 160 μs every time the convert command is issued. For four * channels with 12-bit resolution each, as an example, the convert command will not take more than * 4x12x80 μs plus 160 μs offset, which totals 4 ms. If the DS2450 gets its power through the VCC pin, the * bus master may communicate with other devices on the 1-Wire bus while the DS2450 is busy with A/D * conversions. If the device is powered entirely from the 1-Wire bus, the bus master must instead provide a * strong pullup to 5V for the estimated duration of the conversion in order to provide sufficient energy. * * The conversion is controlled by the input select mask (Figure 7a) and the read-out control byte (Figure * 7b). In the input select mask the bus master specifies which channels participate in the conversion. A * channel is selected if the bit associated to the channel is set to 1. If more than one channel is selected, the * conversion takes place one channel after another in the sequence A, B, C, D, skipping those channels that * are not selected. The bus master can read the result of a channel’s conversion before the conversion of all * the remaining selected channels is completed. In order to distinguish between the previous result and the * new value the bus master uses the read-out control byte. This byte allows presetting the conversion readout * registers for each selected channel to all 1’s or all 0’s. If the expected result is close to 0 then one * should preset to all 1’s or to all 0’s if the conversion result will likely be a high number. In applications * where the bus master can wait until all selected channels are converted before reading, a preset of the * read-out registers is not necessary. Note that for a channel not selected in the input select mask, the * channel’s read-out control setting has no effect. If a channel constantly yields conversion results close to * 0 the channel’s output transistor may be conducting. See section Device Registers for details. * * INPUT SELECT MASK (CONVERSION COMMAND) Figure 7a * bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 * “don’t care” D C B A * * READ-OUT CONTROL (CONVERSION COMMAND) Figure 7b * bit 7 bit 6 bit 5 bit 4 bit 3 bit 2 bit 1 bit 0 * Set D Clear D Set C Clear C Set B Clear B Set A Clear A * * Set Clear Explanation * 0 0 no preset, leave as is * 0 1 preset to all 0’s * 1 0 preset to all 1’s * 1 1 (illegal code) * * Following the Convert command byte the bus master transmits the input select mask and the read-out * control byte. Now the bus master reads the CRC16 of the command byte, select mask and control byte. * The conversion will start no earlier than 10 μs after the most significant bit of the CRC is received by the * bus master. * * With a parasitic power supply the bus master must activate the strong pullup within this 10 μs window for * a duration that is estimated as explained above. After that, the data line returns to an idle high state and * communication on the bus can resume. The bus master would normally send a reset pulse to exit the * Convert command. Read data time slots generated after the strong pullup has ended but before issuing a * reset pulse should result in all 1’s if the conversion time was calculated correctly. * * With VCC power supply the bus master may either send a reset pulse to exit the Convert command or * continuously generate read data time slots. As long as the DS2450 is busy with conversions the bus * master will read 0’s. After the conversion is completed the bus master will receive 1’s instead. Since in a * open-drain environment a single 0 overwrites multiple 1’s the bus master can monitor multiple devices * converting simultaneously and immediately knows when the last one is ready. As in the parasite * powered scenario the bus master finally has to exit the Convert command by issuing a rest pulse. * * from data sheet: http://datasheets.maximintegrated.com/en/ds/DS2450.pdf */ while( trialsCounter < OWI_SEND_BYTE_MAX_TRIALS ) { trialsCounter++; receive_CRC = 0; result = RESULT_OK; printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("bus_pattern: %#x sending command, mask, readout byte"),currentPins ); /* select one or all, depending if id is given */ if ( NULL == id) { /* * SKIP ROM [CCH] * * This command can save time in a single drop bus system by allowing the bus master to access the * memory/convert functions without providing the 64-bit ROM code. If more than one slave is present on * the bus and a read command is issued following the Skip ROM command, data collision will occur on the * bus as multiple slaves transmit simultaneously (open drain pulldowns will produce a wired-AND result). */ OWI_SkipRom(currentPins); result = owiSendBytesAndCheckCRC16(currentPins, 3, DS2450_CONVERT, DS2450_CONVERSION_CHANNEL_SELECT_MASK, DS2450_CONVERSION_READOUT_CONTROL); result = RESULT_OK; /*disable CRC check for skip rom*/ } else { /* * MATCH ROM [55H] * * The match ROM command, followed by a 64-bit ROM sequence, allows the bus master to address a * specific DS2450 on a multidrop bus. Only the DS2450 that exactly matches the 64-bit ROM sequence * will respond to the following memory/convert function command. All slaves that do not match the 64-bit * ROM sequence will wait for a reset pulse. This command can be used with a single or multiple devices * on the bus. */ OWI_MatchRom(id, currentPins); // Match id found earlier result = owiSendBytesAndCheckCRC16(currentPins, 3, DS2450_CONVERT, DS2450_CONVERSION_CHANNEL_SELECT_MASK, DS2450_CONVERSION_READOUT_CONTROL); result = RESULT_OK; /*disable CRC check for skip rom*/ } // printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("crc16 checksum 3 bytes %#x ?"), owiComputeCRC16(0x0000, 3, DS2450_CONVERT, DS2450_CONVERSION_CHANNEL_SELECT_MASK, DS2450_CONVERSION_READOUT_CONTROL) ); // printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("crc16 checksum 4 bytes %#x ?"), owiComputeCRC16(0x0000, 4, OWI_ROM_SKIP, DS2450_CONVERT, DS2450_CONVERSION_CHANNEL_SELECT_MASK, DS2450_CONVERSION_READOUT_CONTROL) ); // printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("crc16 checksum 3 bytes %#x ?"), owiComputeCRC16(0xFFFF, 3, DS2450_CONVERT, DS2450_CONVERSION_CHANNEL_SELECT_MASK, DS2450_CONVERSION_READOUT_CONTROL) ); // printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("crc16 checksum 4 bytes %#x ?"), owiComputeCRC16(0xFFFF, 4, OWI_ROM_SKIP, DS2450_CONVERT, DS2450_CONVERSION_CHANNEL_SELECT_MASK, DS2450_CONVERSION_READOUT_CONTROL) ); if ( RESULT_OK == result ) { break; } else { if (OWI_SEND_BYTE_MAX_TRIALS != trialsCounter) { printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("CRC16 check send byte failed - trial no. %i, computed %#x != received %#x"), trialsCounter); /* ending the Convert command sequence in any case by issuing a Reset Pulse*/ OWI_DetectPresence(currentPins); /*the "DetectPresence" function includes sending a Reset Pulse*/ continue; } else { CommunicationError_p(ERRG, dynamicMessage_ErrorIndex, TRUE, PSTR("CRC16 check reached max trials (%i) on send byte"), OWI_SEND_BYTE_MAX_TRIALS); result = RESULT_FAILURE; break; } } } //loop that waits for the conversion to be done if ( RESULT_OK == result ) { result = RESULT_OK; while ( OWI_ReadBit(currentPins) == 0 ) { _delay_ms(OWI_ADC_CONVERSION_DELAY_MILLISECONDS); /* timeout check */ if ( 0 == --count) { timeout_flag = TRUE; result = RESULT_FAILURE; break; } } printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("waited %i times a delay of %i ms"), maxcount - count, OWI_ADC_CONVERSION_DELAY_MILLISECONDS); /* ending the Convert command sequence in any case by issuing a Reset Pulse*/ OWI_DetectPresence(currentPins); /*the "DetectPresence" function includes sending a Reset Pulse*/ } /* post conversion status analysis*/ if (RESULT_OK == result) { owiAdcTimeoutAndFailureBusMask &= ~(currentPins); result = RESULT_OK; printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("OWI ADC Conversion failed (bus_pattern: %#x)"), currentPins); } else { result = RESULT_FAILURE; if ( NULL == id ) { owiAdcTimeoutAndFailureBusMask |= currentPins; if ( FALSE != timeout_flag ) { CommunicationError_p(ERRG, dynamicMessage_ErrorIndex, TRUE, PSTR("OWI ADC Conversion timeout (bus_pattern: %#x"), currentPins); printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("OWI Adc Conversion timeout (>%i ms) on bus_mask (%#x)"), maxConversionTime, currentPins); } CommunicationError_p(ERRG, dynamicMessage_ErrorIndex, TRUE, PSTR("OWI ADC Conversion failed (bus_pattern: %#x)"), currentPins); } else { owiCreateIdString(owi_id_string, id); if ( FALSE != timeout_flag ) { CommunicationError_p(ERRG, dynamicMessage_ErrorIndex, TRUE, PSTR("OWI ADC Conversion timeout (id: %s"), owi_id_string); printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("OWI Adc Conversion timeout (>%i ms) (id: %s)"), maxConversionTime, owi_id_string); } CommunicationError_p(ERRG, dynamicMessage_ErrorIndex, TRUE, PSTR("OWI ADC Conversion failed (id: %s)"), owi_id_string); } } return result; }
uint8_t owiADCMemoryWriteByte(unsigned char bus_pattern, unsigned char * id, uint16_t address, uint8_t data, uint8_t maxTrials) { uint16_t receive_CRC; uint8_t flag = FALSE; uint8_t verificationData = 0x0; uint8_t trialsCounter = maxTrials; printDebug_p(debugLevelEventDebug, debugSystemOWIADC, __LINE__, filename, PSTR("writing to ADC memory address: %#x \tdata: %#x"),address, data); /* 0 trials, give it a chance */ if (0 == trialsCounter) { trialsCounter++;} while ( FALSE == flag && trialsCounter != 0) { /* select one or all, depending if id is given */ if ( id == NULL) { /* * SKIP ROM [CCH] * * This command can save time in a single drop bus system by allowing the bus master to access the * memory/ convert functions without providing the 64-bit ROM code. If more than one slave is present on * the bus and a read command is issued following the Skip ROM command, data collision will occur on the * bus as multiple slaves transmit simultaneously (open drain pulldowns will produce a wired-AND result). */ OWI_SendByte(OWI_ROM_SKIP, bus_pattern); } else { /* * MATCH ROM [55H] * * The match ROM command, followed by a 64-bit ROM sequence, allows the bus master to address a * specific DS2450 on a multidrop bus. Only the DS2450 that exactly matches the 64-bit ROM sequence * will respond to the following memory/convert function command. All slaves that do not match the 64-bit * ROM sequence will wait for a reset pulse. This command can be used with a single or multiple devices * on the bus. */ OWI_MatchRom(id, bus_pattern); // Match id found earlier } /* * WRITE MEMORY [55H] * * The Write Memory command is used to write to memory pages 1 and 2 in order to set the channel specific * control data and alarm thresholds. The command can also be used to write the single control byte * on page 3 at address 1Ch. The bus master will follow the command byte with a two byte starting address * (TA1=(T7:T0), TA2=(T15:T8)) and a data byte of (D7:D0). A 16-bit CRC of the command byte, address * bytes, and data byte is computed by the DS2450 and read back by the bus master to confirm that the * correct command word, starting address, and data byte were received. Now the DS2450 copies the data * byte to the specified memory location. With the next eight time slots the bus master receives a copy of * the same byte but read from memory for verification. If the verification fails, a Reset Pulse should be * issued and the current byte address should be written again. * If the bus master does not issue a Reset Pulse and the end of memory was not yet reached, the DS2450 * will automatically increment its address counter to address the next memory location. The new two-byte * address will also be loaded into the 16-bit CRC-generator as a starting value. The bus master will send * the next byte using eight write time slots. As the DS2450 receives this byte it also shifts * it into the CRCgenerator and the result is a 16-bit CRC of the new data byte and the new address. * With the next sixteen read time slots the bus master * will read this 16-bit CRC from the DS2450 to verify that the address * incremented properly and the data byte was received correctly. Following the CRC the master receives * the byte just written as read from the memory. If the CRC or read-back byte is incorrect, a Reset Pulse * should be issued in order to repeat the Write Memory command sequence. * Note that the initial pass through the Write Memory flow chart will generate a 16-bit CRC value that is * the result of shifting the command byte into the CRC-generator, followed by the two address bytes, and * finally the data byte. Subsequent passes through the Write Memory flow chart due to the DS2450 * automatically incrementing its address counter will generate a 16-bit CRC that is the result of loading (not * shifting) the new (incremented) address into the CRC-generator and then shifting in the new data byte. * The decision to continue after having received a bad CRC or if the verification fails is made entirely by * the bus master. Write access to the conversion read-out registers is not possible. If a write attempt is * made to a page 0 address the device will follow the Write Memory flow chart correctly but the * verification of the data byte read back from memory will usually fail. The Write Memory command * sequence can be ended at any point by issuing a Reset Pulse. * */ OWI_SendByte(DS2450_WRITE_MEMORY, bus_pattern); OWI_SendWord(address, bus_pattern); OWI_SendByte(data, bus_pattern); /* receive 16bit CRC */ receive_CRC = OWI_ReceiveWord(bus_pattern); /* IMPORTANT AFTER EACH 'MEMORY WRITE' OPERATION to start memory writing*/ /* only possible if there is not OWI_ROM_SKIP, so wait until this device specific is implemented*/ if (id != NULL) { #warning TODO: add a complex check on the CRC, including the correct address, if in single device mode /*verify written data*/ verificationData = OWI_ReceiveByte(bus_pattern); if ( data == verificationData ) /* check passed */ { flag = TRUE; } else { trialsCounter--; } } else { flag = TRUE; } /* ending the Write Memory command sequence by issuing a Reset Pulse*/ OWI_DetectPresence(bus_pattern); /*the "DetectPresence" function includes sending a Reset Pulse*/ } /*end of while loop */ if (FALSE == flag) { return 1; } else { return 0; } }