Klasse RS485 (bus_rs485.py)
Der Code darf nicht kommerziell genutzt werden! # -*- coding: utf-8 -*- # Access to RS485 Bus with protocol handling # (c) Franz Stoiber # The commercial use of this code is not allowed # History # 2012-12-13 begin programming # 2013-02-17 time messurement improved # 2013-03-21 class and function names harmonized # 2014-08-31 adapted for half duplex # 2015-11-26 half and full duplex harmonized # 2016-04-17 logging adapted # 2016-04-24 GPIO included # 2016-04-29 device name added in error messages # 2016-09-29 recv changed # 2016-10-02 new ErrNr 128 # 2016-11-21 LogErr added # 2017-03-25 V1 # 2017-03-30 both protocols # V2 # 2017-03-26 prepared for new protocol # V3 # 2017-03-26 protocol weather deleted # V4 # 2017-03-26 changed to new %S485 protocol # V5 # Remarks # protocol # command: [n+4][adr][cmd][byte_1]...[byte_n][crc] # answer: [n+6][adr][cmd+128][eRx][eTx][byte_1]...[byte_n][crc] import serial import time import logging LOG = logging.getLogger('main') class RS485: global LogErr global LedErr def init(self, BusName, BaudRate, DeviveName): self.DeviveName = DeviveName self.LogErr = True self.LedErr = False self.Duration = None try: self.Bus = serial.Serial(BusName, \ baudrate = BaudRate, \ parity = 'N', \ bytesize = 8, \ stopbits = 1) LOG.info('RS485: ' + BusName + ', ' + str(BaudRate) + ' Baud') self.Bus.timeout = .2 self.Bus.read(size = 10) self.Bus.timeout = None except: LOG.error('RS485: error initializing bus ' + BusName) return def initGPIO(self, GPIO, PinLedErr): self.GPIO = GPIO self.PinLedErr = PinLedErr self.LedErr = True return def sendCmd(self, Adr, Cmd, Param, ExpectedLength, TimeOut): Answer = () self.Duration = time.time() self.Bus.flushInput() State = self.sendFrame(Adr, Cmd, Param) if State: Result = self.recvFrame(Adr, Cmd, ExpectedLength, TimeOut) State = Result[0] Answer = Result[1] Duration = time.time() - self.Duration return(State, Answer, Duration) def sendFrame(self, Adr, Cmd, Param): State = False Length = len(Param) + 4 CheckSum = Length + Adr + Cmd for i in range(len(Param)): CheckSum += ord(Param[i]) CSum = CheckSum % 256 Command = chr(Length) + chr(Adr) + chr(Cmd) + Param + chr(CSum) LogValue = 'Tx: ' for i in range(len(Command)): LogValue += '%03d' % (ord(Command[i])) + ' ' LogValue += '~' self.TxValue = LogValue LOG.debug(LogValue) try: self.Bus.write(Command) State = True except: LOG.error('RS485: error sending command ' + LogValue) return(State) def recvFrame(self, Adr, Cmd, ExpectedLength, TimeOut): State = False TxErr = 0 Data = () self.Bus.timeout = TimeOut RecvData = self.Bus.read(size = 1) if RecvData != '': RecvData += self.Bus.read(size = ExpectedLength - 1) while self.Bus.inWaiting() > 0: RecvData += self.Bus.read(size = self.Bus.inWaiting()) FrameLength = len(RecvData) Frame = () for i in range(FrameLength): Frame += (ord(RecvData[i]),) LogValue = 'Rx: ' for i in range(FrameLength): LogValue += '%03d' % (Frame[i]) + ' ' LogValue += '~' LOG.debug(LogValue) CheckSum = 0 for i in range(FrameLength - 1): CheckSum += Frame[i] CSum = CheckSum % 256 Duration = ' (' + '%2d'%((time.time() - self.Duration)*1000) + 'ms)' try: DeviceNameAdr = self.DeviveName[Adr] except KeyError: DeviceNameAdr = 'undefined device' DeviceNameAdr += ' (adr ' + str(Adr) + '): ' if FrameLength == 0 and ExpectedLength > 0 and self.LogErr: LOG.error('RS485: no answer received from ' + DeviceNameAdr + self.TxValue + Duration) elif FrameLength < 6: LOG.error('RS485: answer to short from ' + DeviceNameAdr + self.TxValue + ' ' + LogValue + Duration) elif FrameLength != ExpectedLength and FrameLength != 6: LOG.error('rs485: unexpected length of answer from ' + DeviceNameAdr + self.TxValue + ' ' + LogValue + Duration) elif FrameLength <> Frame[0]: LOG.error('RS485: wrong length of answer from ' + DeviceNameAdr + self.TxValue + ' ' + LogValue + Duration) elif CSum != Frame[FrameLength - 1]: LOG.error('RS485: checksum-error in answer from ' + DeviceNameAdr + self.TxValue + ' ' + ' ' + LogValue + Duration) elif Frame[1] != Adr: LOG.error('RS485: address does not match in answer from ' + DeviceNameAdr + self.TxValue + ' ' + LogValue + Duration) elif Frame[2] != Cmd + 128: LOG.error('RS485: command does not match in answer from ' + DeviceNameAdr + self.TxValue + ' ' + LogValue + Duration) elif Frame[3] == 1: LOG.error('RS485: received more bytes as defined in frame ' + DeviceNameAdr + self.TxValue + ' ' + LogValue + Duration) elif Frame[3] == 2: LOG.error('RS485: receive buffer overrun ' + DeviceNameAdr + self.TxValue + ' ' + LogValue + Duration) elif Frame[3] == 3: LOG.error('RS485: received less bytes as defined in frame ' + DeviceNameAdr + self.TxValue + ' ' + LogValue + Duration) elif Frame[3] == 4: LOG.error('RS485: checksum error in received frame ' + DeviceNameAdr + self.TxValue + ' ' + LogValue + Duration) elif Frame[3] != 0: LOG.error('RS485: undefind receive error ' + DeviceNameAdr + self.TxValue + ' ' + LogValue + Duration) else: State = True TxErr = Frame[4] for i in range(5, FrameLength - 1): Data += (Frame[i],) return(State, (TxErr, Data))

 Klasse RS485 (Bus_RS485.h)
Der Code darf nicht kommerziell genutzt werden! /* RS485_h - Library for controlling the RS485 bus Created by Franz Stoiber 2014-17. Hints ------------------------------------------------------- The commercial use of this firmware is not allowed. ------------------------------------------------------------- */ #ifndef Bus_RS485_h #define Bus_RS485_h #include "Arduino.h" class RS485 { public: byte Version = 6; void init(int TimeoutMil, byte PinDE); void begin(unsigned long BaudRate); void end(); boolean receiveFrame(byte Adr); void sendFrame(byte Adr, byte TxLen); void clearTxBuffer(); #define BCASTAdr 255 #define RxBufferLen 40 byte RxCmd; byte RxData[RxBufferLen - 4]; byte RxErr; #define TxBufferLen 45 byte TxData[TxBufferLen - 6]; byte TxErr; private: byte calcCheckSum(byte InitVal, byte Buffer[], byte TxStart, int Len); void clearRxBuffer(); unsigned long TimeoutMillis; unsigned long ReadDelayMicros; byte PinBDE; byte RxBuffer[RxBufferLen]; byte TxBuffer[TxBufferLen]; byte RxLen; }; #endif

 Klasse RS485 (Bus_RS485.cpp)
Der Code darf nicht kommerziell genutzt werden! /* RS485.cpp - Library for controlling the RS485 bus Created by Franz Stoiber 2014-17 Hints ------------------------------------------------------- The commercial use of this firmware is not allowed. ------------------------------------------------------------- History ----------------------------------------------------- 2014-07-08 begin programming 2014-09-26 V0 2015-11-25 RS485_weather included 2015-12-02 new receiving algorithm for protocol heating 2017-03-24 bugfix computing TimeoutTime V1 2017-03-24 new receiving algorithm for protocol weather V2 2017-03-24 harmonized receive and send algorithm V3 2017-03-29 doHeatingCmd replaced with sendCmd V4 2017-04-06 new protocol BCASTAdr set to 255 V5 2017-04-07 new protocol no led V6 ------------------------------------------------------------- ToDo -------------------------------------------------------- ------------------------------------------------------------- Bugs -------------------------------------------------------- ------------------------------------------------------------- Marks ------------------------------------------------------- ------------------------------------------------------------- protocol rs485 ---------------------------------------------- command: [n+4][adr][cmd][byte_1]...[byte_n][cs] answer: [n+6][adr][cmd+128][eRx][eTx][byte_1]...[byte_n][cs] errors 1: received frame with more bytes as defined 2: receive buffer overrun 3: received frame with less bytes as defined 4: received frame with checksum error ------------------------------------------------------------- */ #include "Arduino.h" #include "Bus_RS485.h" void RS485::init(int TimeoutMil, byte PinDE) { TimeoutMillis = (unsigned long)TimeoutMil; PinBDE = PinDE; pinMode(PinBDE, OUTPUT); digitalWrite(PinBDE, 0); } void RS485::begin(unsigned long BaudRate) { Serial.begin(BaudRate); ReadDelayMicros = 10000000/BaudRate; } void RS485::end() { Serial.end(); } boolean RS485::receiveFrame(byte Adr) { byte i; byte RxLen; byte RxNrBytesRead; byte RxCSum; if (Serial.available()) { clearRxBuffer(); RxLen = (byte)Serial.read(); delayMicroseconds(ReadDelayMicros); if (RxLen < RxBufferLen) { Serial.setTimeout(TimeoutMillis); RxNrBytesRead = Serial.readBytes(RxBuffer, RxLen - 1); delayMicroseconds(ReadDelayMicros); } while (Serial.available()) { if (RxNrBytesRead < RxBufferLen) { RxBuffer[RxNrBytesRead] = Serial.read(); RxErr = 1; //more bytes as defined } else { Serial.read(); RxErr = 2; //buffer overrun } RxNrBytesRead += 1; delayMicroseconds(ReadDelayMicros); } if (RxBuffer[0] != Adr && RxBuffer[0] != BCASTAdr && RxBuffer[0] != 5) return(false); if (RxErr != 0) { if (RxNrBytesRead > 0) RxCmd = RxBuffer[1]; return(true); } if (RxLen - 1 == RxNrBytesRead) { RxCSum = calcCheckSum(RxLen, RxBuffer, 0, RxNrBytesRead - 1); if (RxCSum != RxBuffer[RxNrBytesRead - 1]) RxErr = 4; //cs error } else RxErr = 3; //less bytes as defined RxCmd = RxBuffer[1]; for (i = 0; i < RxLen - 4; i++) RxData[i] = RxBuffer[i + 2]; return(true); } else return(false); } void RS485::sendFrame(byte Adr, byte TxDataLen) { byte i; byte TxLen; byte TxCSum; digitalWrite(PinBDE, 1); TxLen = TxDataLen + 6; TxBuffer[0] = TxLen; TxBuffer[1] = Adr; TxBuffer[2] = RxCmd + 128; TxBuffer[3] = RxErr; TxBuffer[4] = TxErr; for (i = 0; i < TxDataLen; i++) TxBuffer[5 + i] = TxData[i]; TxCSum = calcCheckSum(0, TxBuffer, 0, TxLen - 1); TxBuffer[TxLen - 1] = TxCSum; Serial.write(TxBuffer, TxLen); Serial.flush(); TxErr = 0; digitalWrite(PinBDE, 0); } byte RS485::calcCheckSum(byte InitVal, byte Buffer[], byte TxStart, int Len) { byte CSum = InitVal; for (byte i = TxStart; i < Len; i++) CSum += Buffer[i]; return(CSum); } void RS485::clearRxBuffer() { byte i; for (i = 0; i < RxBufferLen; i++) RxBuffer[i] = 255; for (i = 0; i < RxBufferLen - 4; i++) RxData[i] = 255; RxErr = 0; } void RS485::clearTxBuffer() { byte i; for (i = 0; i < TxBufferLen; i++) TxBuffer[i] = 255; }