diff --git a/IO_Modbus.cpp b/IO_Modbus.cpp
index 4c7df51..7404b12 100644
--- a/IO_Modbus.cpp
+++ b/IO_Modbus.cpp
@@ -19,7 +19,468 @@
 
 #include "IO_Modbus.h"
 #include "defines.h"
+void ModbusADU::setTransactionId(uint16_t transactionId) {
+  _setRegister(tcp, 0, transactionId);
+}
 
+void ModbusADU::setProtocolId(uint16_t protocolId) {
+  _setRegister(tcp, 2, protocolId);
+}
+
+void ModbusADU::setLength(uint16_t length) {
+  if (length < 3 || length > 254) _setRegister(tcp, 4, 0);
+  else _setRegister(tcp, 4, length);
+}
+
+void ModbusADU::setUnitId(uint8_t unitId) {
+  tcp[6] = unitId;
+}
+
+void ModbusADU::setFunctionCode(uint8_t functionCode) {
+  pdu[0] = functionCode;
+}
+
+void ModbusADU::setDataRegister(uint8_t index, uint16_t value) {
+  _setRegister(data, index, value);
+}
+
+
+
+void ModbusADU::setRtuLen(uint16_t rtuLen) {
+  setLength(rtuLen - 2);
+}
+
+void ModbusADU::setTcpLen(uint16_t tcpLen) {
+  setLength(tcpLen - 6);
+}
+
+void ModbusADU::setPduLen(uint16_t pduLen) {
+  setLength(pduLen + 1);
+}
+
+void ModbusADU::setDataLen(uint16_t dataLen) {
+  setLength(dataLen + 2);
+}
+
+
+
+uint16_t ModbusADU::getTransactionId() {
+  return _getRegister(tcp, 0);
+}
+
+uint16_t ModbusADU::getProtocolId() {
+  return _getRegister(tcp, 2);
+}
+
+uint16_t ModbusADU::getLength() {
+  uint16_t length = _getRegister(tcp, 4);
+  if (length < 3 || length > 254) return 0;
+  else return length;
+}
+
+uint8_t ModbusADU::getUnitId() {
+  return tcp[6];
+}
+
+uint8_t ModbusADU::getFunctionCode() {
+  return pdu[0];
+}
+
+uint16_t ModbusADU::getDataRegister(uint8_t index) {
+  return _getRegister(data, index);
+}
+
+
+
+uint16_t ModbusADU::getRtuLen() {
+  uint16_t len = getLength();
+  if (len == 0) return 0;
+  else return len + 2;
+}
+
+uint16_t ModbusADU::getTcpLen() {
+  uint16_t len = getLength();
+  if (len == 0) return 0;
+  else return len + 6;
+}
+
+uint16_t ModbusADU::getPduLen() {
+  uint16_t len = getLength();
+  if (len == 0) return 0;
+  else return len - 1;
+}
+
+uint16_t ModbusADU::getDataLen() {
+  uint16_t len = getLength();
+  if (len == 0) return 0;
+  else return len - 2;
+}
+
+
+
+void ModbusADU::updateCrc() {
+  uint16_t len = getLength();
+  uint16_t crc = _calculateCrc(len);
+  rtu[len] = lowByte(crc);
+  rtu[len + 1] = highByte(crc);
+}
+
+bool ModbusADU::crcGood() {
+  uint16_t len = getLength();
+  uint16_t aduCrc = rtu[len] | (rtu[len + 1] << 8);
+  uint16_t calculatedCrc = _calculateCrc(len);
+  if (aduCrc == calculatedCrc) return true;
+  else return false;
+}
+
+
+
+void ModbusADU::prepareExceptionResponse(uint8_t exceptionCode) {
+  pdu[0] |= 0x80;
+  pdu[1] = exceptionCode;
+  setPduLen(2);
+}
+
+
+
+void ModbusADU::_setRegister(uint8_t *buf, uint16_t index, uint16_t value) {
+  buf[index] = highByte(value);
+  buf[index + 1] = lowByte(value);
+}
+
+uint16_t ModbusADU::_getRegister(uint8_t *buf, uint16_t index) {
+  return (buf[index] << 8) | buf[index + 1];
+}
+
+uint16_t ModbusADU::_calculateCrc(uint16_t len) {
+  uint16_t value = 0xFFFF;
+  for (uint16_t i = 0; i < len; i++) {
+    value ^= (uint16_t)rtu[i];
+    for (uint8_t j = 0; j < 8; j++) {
+      bool lsb = value & 1;
+      value >>= 1;
+      if (lsb == true) value ^= 0xA001;
+    }
+  }
+  return value;
+}
+
+
+
+uint16_t div8RndUp(uint16_t value) {
+  return (value + 7) >> 3;
+}
+
+ModbusRTUComm::ModbusRTUComm(Stream& serial, int8_t dePin, int8_t rePin) : _serial(serial) {
+  _dePin = dePin;
+  _rePin = rePin;
+}
+
+void ModbusRTUComm::begin(unsigned long baud, uint32_t config) {
+  unsigned long bitsPerChar;
+  switch (config) {
+    case SERIAL_8E2:
+    case SERIAL_8O2:
+      bitsPerChar = 12;
+      break;
+    case SERIAL_8N2:
+    case SERIAL_8E1:
+    case SERIAL_8O1:
+      bitsPerChar = 11;
+      break;
+    case SERIAL_8N1:
+    default:
+      bitsPerChar = 10;
+      break;
+  }
+  if (baud <= 19200) {
+    _charTimeout = (bitsPerChar * 2500000) / baud;
+    _frameTimeout = (bitsPerChar * 4500000) / baud;
+  }
+  else {
+    _charTimeout = (bitsPerChar * 1000000) / baud + 750;
+    _frameTimeout = (bitsPerChar * 1000000) / baud + 1750;
+  }
+  #if defined(ARDUINO_UNOR4_MINIMA) || defined(ARDUINO_UNOR4_WIFI) || defined(ARDUINO_GIGA) || (defined(ARDUINO_NANO_RP2040_CONNECT) && defined(ARDUINO_ARCH_MBED))
+  _postDelay = ((bitsPerChar * 1000000) / baud) + 2;
+  #endif
+  if (_dePin >= 0) {
+    pinMode(_dePin, OUTPUT);
+    digitalWrite(_dePin, LOW);
+  }
+  if (_rePin >= 0) {
+    pinMode(_rePin, OUTPUT);
+    digitalWrite(_rePin, LOW);
+  }
+  clearRxBuffer();
+}
+
+void ModbusRTUComm::setTimeout(unsigned long timeout) {
+  _readTimeout = timeout;
+}
+
+ModbusRTUCommError ModbusRTUComm::readAdu(ModbusADU& adu) {
+  adu.setRtuLen(0);
+  unsigned long startMillis = millis();
+  while (!_serial.available()) {
+    if (millis() - startMillis >= _readTimeout) return MODBUS_RTU_COMM_TIMEOUT;
+  }
+  uint16_t len = 0;
+  unsigned long startMicros = micros();
+  do {
+    if (_serial.available()) {
+      startMicros = micros();
+      adu.rtu[len] = _serial.read();
+      len++;
+    }
+  } while (micros() - startMicros <= _charTimeout && len < 256);
+  adu.setRtuLen(len);
+  while (micros() - startMicros < _frameTimeout);
+  if (_serial.available()) {
+    adu.setRtuLen(0);
+    return MODBUS_RTU_COMM_FRAME_ERROR;
+  }
+  if (!adu.crcGood()) {
+    adu.setRtuLen(0);
+    return MODBUS_RTU_COMM_CRC_ERROR;
+  }
+  return MODBUS_RTU_COMM_SUCCESS;
+}
+
+void ModbusRTUComm::writeAdu(ModbusADU& adu) {
+  adu.updateCrc();
+  if (_dePin >= 0) digitalWrite(_dePin, HIGH);
+  if (_rePin >= 0) digitalWrite(_rePin, HIGH);
+  _serial.write(adu.rtu, adu.getRtuLen());
+  _serial.flush();
+  delayMicroseconds(_postDelay);
+  if (_dePin >= 0) digitalWrite(_dePin, LOW);
+  if (_rePin >= 0) digitalWrite(_rePin, LOW);
+}
+
+void ModbusRTUComm::clearRxBuffer() {
+  unsigned long startMicros = micros();
+  do {
+    if (_serial.available() > 0) {
+      startMicros = micros();
+      _serial.read();
+    }
+  } while (micros() - startMicros < _frameTimeout);
+}
+
+ModbusRTUMaster::ModbusRTUMaster(Stream& serial, int8_t dePin, int8_t rePin) : _rtuComm(serial, dePin, rePin) {
+  _rtuComm.setTimeout(500);
+}
+
+void ModbusRTUMaster::setTimeout(unsigned long timeout) {
+  _rtuComm.setTimeout(timeout);
+}
+
+void ModbusRTUMaster::begin(unsigned long baud, uint32_t config) {
+  _rtuComm.begin(baud, config);
+}
+
+
+
+ModbusRTUMasterError ModbusRTUMaster::readCoils(uint8_t id, uint16_t startAddress, bool buf[], uint16_t quantity) {
+  return _readValues(id, 1, startAddress, buf, quantity);
+}
+
+ModbusRTUMasterError ModbusRTUMaster::readDiscreteInputs(uint8_t id, uint16_t startAddress, bool buf[], uint16_t quantity) {
+  return _readValues(id, 2, startAddress, buf, quantity);
+}
+
+ModbusRTUMasterError ModbusRTUMaster::readHoldingRegisters(uint8_t id, uint16_t startAddress, uint16_t buf[], uint16_t quantity) {
+  return _readValues(id, 3, startAddress, buf, quantity);
+}
+
+ModbusRTUMasterError ModbusRTUMaster::readInputRegisters(uint8_t id, uint16_t startAddress, uint16_t buf[], uint16_t quantity) {
+  return _readValues(id, 4, startAddress, buf, quantity);
+}
+
+
+
+ModbusRTUMasterError ModbusRTUMaster::writeSingleCoil(uint8_t id, uint16_t address, bool value) {
+  return _writeSingleValue(id, 5, address, ((value) ? 0xFF00 : 0x0000));
+}
+
+ModbusRTUMasterError ModbusRTUMaster::writeSingleHoldingRegister(uint8_t id, uint16_t address, uint16_t value) {
+  return _writeSingleValue(id, 6, address, value);
+}
+
+
+
+ModbusRTUMasterError ModbusRTUMaster::writeMultipleCoils(uint8_t id, uint16_t startAddress, bool buf[], uint16_t quantity) {
+  const uint8_t functionCode = 15;
+  if (id > 247) return MODBUS_RTU_MASTER_INVALID_ID;
+  if (!buf) return MODBUS_RTU_MASTER_INVALID_BUFFER;
+  if (quantity == 0 || quantity > 1968) return MODBUS_RTU_MASTER_INVALID_QUANTITY;
+  ModbusADU adu;
+  uint16_t byteCount = div8RndUp(quantity);
+  adu.setUnitId(id);
+  adu.setFunctionCode(functionCode);
+  adu.setDataRegister(0, startAddress);
+  adu.setDataRegister(2, quantity);
+  adu.data[4] = byteCount;
+  for (uint16_t i = 0; i < quantity; i++) {
+    bitWrite(adu.data[5 + (i >> 3)], i & 7, buf[i]);
+  }
+  for (uint16_t i = quantity; i < (byteCount * 8); i++) {
+    bitClear(adu.data[5 + (i >> 3)], i & 7);
+  }
+  adu.setDataLen(5 + byteCount);
+  _rtuComm.writeAdu(adu);
+  if (id == 0) return MODBUS_RTU_MASTER_SUCCESS;
+  ModbusRTUCommError commError = _rtuComm.readAdu(adu);
+  if (commError) return _translateCommError(commError);
+  if (adu.getUnitId() != id) return MODBUS_RTU_MASTER_UNEXPECTED_ID;
+  if (adu.getFunctionCode() == (functionCode + 0x80)) {
+    _exceptionResponse = adu.data[0];
+    return MODBUS_RTU_MASTER_EXCEPTION_RESPONSE;
+  }
+  if (adu.getFunctionCode() != functionCode) return MODBUS_RTU_MASTER_UNEXPECTED_FUNCTION_CODE;
+  if (adu.getDataLen() != 4) return MODBUS_RTU_MASTER_UNEXPECTED_LENGTH;
+  if (adu.getDataRegister(0) != startAddress) return MODBUS_RTU_MASTER_UNEXPECTED_ADDRESS;
+  if (adu.getDataRegister(2) != quantity) return MODBUS_RTU_MASTER_UNEXPECTED_QUANTITY;
+  return MODBUS_RTU_MASTER_SUCCESS;
+}
+
+ModbusRTUMasterError ModbusRTUMaster::writeMultipleHoldingRegisters(uint8_t id, uint16_t startAddress, uint16_t buf[], uint16_t quantity) {
+  uint8_t functionCode = 16;
+  if (id > 247) return MODBUS_RTU_MASTER_INVALID_ID;
+  if (!buf) return MODBUS_RTU_MASTER_INVALID_BUFFER;
+  if (quantity == 0 || quantity > 123) return MODBUS_RTU_MASTER_INVALID_QUANTITY;
+  uint16_t byteCount = quantity * 2;
+  ModbusADU adu;
+  adu.setUnitId(id);
+  adu.setFunctionCode(functionCode);
+  adu.setDataRegister(0, startAddress);
+  adu.setDataRegister(2, quantity);
+  adu.data[4] = byteCount;
+  for (uint16_t i = 0; i < quantity; i++) {
+    adu.setDataRegister(5 + (i * 2), buf[i]);
+  }
+  adu.setDataLen(5 + byteCount);
+  _rtuComm.writeAdu(adu);
+  if (id == 0) return MODBUS_RTU_MASTER_SUCCESS;
+  ModbusRTUCommError commError = _rtuComm.readAdu(adu);
+  if (commError) return _translateCommError(commError);
+  if (adu.getUnitId() != id) return MODBUS_RTU_MASTER_UNEXPECTED_ID;
+  if (adu.getFunctionCode() == (functionCode + 0x80)) {
+    _exceptionResponse = adu.data[0];
+    return MODBUS_RTU_MASTER_EXCEPTION_RESPONSE;
+  }
+  if (adu.getFunctionCode() != functionCode) return MODBUS_RTU_MASTER_UNEXPECTED_FUNCTION_CODE;
+  if (adu.getDataLen() != 4) return MODBUS_RTU_MASTER_UNEXPECTED_LENGTH;
+  if (adu.getDataRegister(0) != startAddress) return MODBUS_RTU_MASTER_UNEXPECTED_ADDRESS;
+  if (adu.getDataRegister(2) != quantity) return MODBUS_RTU_MASTER_UNEXPECTED_QUANTITY;
+  return MODBUS_RTU_MASTER_SUCCESS;
+}
+
+
+
+uint8_t ModbusRTUMaster::getExceptionResponse() {
+  return _exceptionResponse;
+}
+
+
+
+ModbusRTUMasterError ModbusRTUMaster::_readValues(uint8_t id, uint8_t functionCode, uint16_t startAddress, bool buf[], uint16_t quantity) {
+  if (id < 1 || id > 247) return MODBUS_RTU_MASTER_INVALID_ID;
+  if (!buf) return MODBUS_RTU_MASTER_INVALID_BUFFER;
+  if (quantity == 0 || quantity > 2000) return MODBUS_RTU_MASTER_INVALID_QUANTITY;
+  ModbusADU adu;
+  adu.setUnitId(id);
+  adu.setFunctionCode(functionCode);
+  adu.setDataRegister(0, startAddress);
+  adu.setDataRegister(2, quantity);
+  adu.setDataLen(4);
+  _rtuComm.writeAdu(adu);
+  ModbusRTUCommError commError = _rtuComm.readAdu(adu);
+  if (commError) return _translateCommError(commError);
+  if (adu.getUnitId() != id) return MODBUS_RTU_MASTER_UNEXPECTED_ID;
+  if (adu.getFunctionCode() == (functionCode + 0x80)) {
+    _exceptionResponse = adu.data[0];
+    return MODBUS_RTU_MASTER_EXCEPTION_RESPONSE;
+  }
+  if (adu.getFunctionCode() != functionCode) return MODBUS_RTU_MASTER_UNEXPECTED_FUNCTION_CODE;
+  uint16_t byteCount = div8RndUp(quantity);
+  if (adu.getDataLen() != (1 + byteCount)) return MODBUS_RTU_MASTER_UNEXPECTED_LENGTH;
+  if (adu.data[0] != byteCount) return MODBUS_RTU_MASTER_UNEXPECTED_BYTE_COUNT;
+  for (uint16_t i = 0; i < quantity; i++) {
+    buf[i] = bitRead(adu.data[1 + (i >> 3)], i & 7);
+  }
+  return MODBUS_RTU_MASTER_SUCCESS;
+}
+
+ModbusRTUMasterError ModbusRTUMaster::_readValues(uint8_t id, uint8_t functionCode, uint16_t startAddress, uint16_t buf[], uint16_t quantity) {
+  if (id < 1 || id > 247) return MODBUS_RTU_MASTER_INVALID_ID;
+  if (!buf) return MODBUS_RTU_MASTER_INVALID_BUFFER;
+  if (quantity == 0 || quantity > 125) return MODBUS_RTU_MASTER_INVALID_QUANTITY;
+  ModbusADU adu;
+  adu.setUnitId(id);
+  adu.setFunctionCode(functionCode);
+  adu.setDataRegister(0, startAddress);
+  adu.setDataRegister(2, quantity);
+  adu.setDataLen(4);
+  _rtuComm.writeAdu(adu);
+  ModbusRTUCommError commError = _rtuComm.readAdu(adu);
+  if (commError) return _translateCommError(commError);
+  if (adu.getUnitId() != id) return MODBUS_RTU_MASTER_UNEXPECTED_ID;
+  if (adu.getFunctionCode() == (functionCode + 0x80)) {
+    _exceptionResponse = adu.data[0];
+    return MODBUS_RTU_MASTER_EXCEPTION_RESPONSE;
+  }
+  if (adu.getFunctionCode() != functionCode) return MODBUS_RTU_MASTER_UNEXPECTED_FUNCTION_CODE;
+  uint16_t byteCount = quantity * 2;
+  if (adu.getDataLen() != (1 + byteCount)) return MODBUS_RTU_MASTER_UNEXPECTED_LENGTH;
+  if (adu.data[0] != byteCount) return MODBUS_RTU_MASTER_UNEXPECTED_BYTE_COUNT;
+  for (uint16_t i = 0; i < quantity; i++) {
+    buf[i] = adu.getDataRegister(1 + (i * 2));
+  }
+  return MODBUS_RTU_MASTER_SUCCESS;
+}
+
+ModbusRTUMasterError ModbusRTUMaster::_writeSingleValue(uint8_t id, uint8_t functionCode, uint16_t address, uint16_t value) {
+  if (id > 247) return MODBUS_RTU_MASTER_INVALID_ID;
+  ModbusADU adu;
+  adu.setUnitId(id);
+  adu.setFunctionCode(functionCode);
+  adu.setDataRegister(0, address);
+  adu.setDataRegister(2, value);
+  adu.setDataLen(4);
+  _rtuComm.writeAdu(adu);
+  if (id == 0) return MODBUS_RTU_MASTER_SUCCESS;
+  ModbusRTUCommError commError = _rtuComm.readAdu(adu);
+  if (commError) return _translateCommError(commError);
+  if (adu.getUnitId() != id) return MODBUS_RTU_MASTER_UNEXPECTED_ID;
+  if (adu.getFunctionCode() == (functionCode + 0x80)) {
+    _exceptionResponse = adu.data[0];
+    return MODBUS_RTU_MASTER_EXCEPTION_RESPONSE;
+  }
+  if (adu.getFunctionCode() != functionCode) return MODBUS_RTU_MASTER_UNEXPECTED_FUNCTION_CODE;
+  if (adu.getDataLen() != 4) return MODBUS_RTU_MASTER_UNEXPECTED_LENGTH;
+  if (adu.getDataRegister(0) != address) return MODBUS_RTU_MASTER_UNEXPECTED_ADDRESS;
+  if (adu.getDataRegister(2) != value) return MODBUS_RTU_MASTER_UNEXPECTED_VALUE;
+  return MODBUS_RTU_MASTER_SUCCESS;
+}
+
+
+
+ModbusRTUMasterError ModbusRTUMaster::_translateCommError(ModbusRTUCommError commError) {
+  switch (commError) {
+    case MODBUS_RTU_COMM_SUCCESS:
+      return MODBUS_RTU_MASTER_SUCCESS;
+    case MODBUS_RTU_COMM_TIMEOUT:
+      return MODBUS_RTU_MASTER_RESPONSE_TIMEOUT;
+    case MODBUS_RTU_COMM_FRAME_ERROR:
+      return MODBUS_RTU_MASTER_FRAME_ERROR;
+    case MODBUS_RTU_COMM_CRC_ERROR:
+      return MODBUS_RTU_MASTER_CRC_ERROR;
+    default:
+      return MODBUS_RTU_MASTER_UNKNOWN_COMM_ERROR;
+  }
+}
 
 /************************************************************
  * Modbus implementation
diff --git a/IO_Modbus.h b/IO_Modbus.h
index 4933eeb..be5b65b 100644
--- a/IO_Modbus.h
+++ b/IO_Modbus.h
@@ -52,7 +52,129 @@
 #define IO_MODBUS_H
 
 #include "IODevice.h"
-#include "ModbusRTUMaster.h"
+class ModbusADU {
+  public:
+    uint8_t *rtu = _adu + 6;
+    uint8_t *tcp = _adu;
+    uint8_t *pdu = _adu + 7;
+    uint8_t *data = _adu + 8;
+
+    void setTransactionId(uint16_t transactionId);
+    void setProtocolId(uint16_t protocolId);
+    void setLength(uint16_t length);
+    void setUnitId(uint8_t unitId);
+    void setFunctionCode(uint8_t functionCode);
+    void setDataRegister(uint8_t index, uint16_t value);
+
+    void setRtuLen(uint16_t rtuLen);
+    void setTcpLen(uint16_t tcpLen);
+    void setPduLen(uint16_t pduLen);
+    void setDataLen(uint16_t dataLen);
+
+    uint16_t getTransactionId();
+    uint16_t getProtocolId();
+    uint16_t getLength();
+    uint8_t getUnitId();
+    uint8_t getFunctionCode();
+    uint16_t getDataRegister(uint8_t index);
+
+    uint16_t getRtuLen();
+    uint16_t getTcpLen();
+    uint16_t getPduLen();
+    uint16_t getDataLen();
+
+    void updateCrc();
+    bool crcGood();
+
+    void prepareExceptionResponse(uint8_t exceptionCode);
+
+  private:
+    uint8_t _adu[262];
+    void _setRegister(uint8_t *buf, uint16_t index, uint16_t value);
+    uint16_t _getRegister(uint8_t *buf, uint16_t index);
+    uint16_t _calculateCrc(uint16_t len);
+    
+};
+
+uint16_t  div8RndUp(uint16_t value);
+
+enum ModbusRTUCommError : uint8_t {
+  MODBUS_RTU_COMM_SUCCESS = 0,
+  MODBUS_RTU_COMM_TIMEOUT = 1,
+  MODBUS_RTU_COMM_FRAME_ERROR = 2,
+  MODBUS_RTU_COMM_CRC_ERROR = 3
+};
+
+class ModbusRTUComm {
+  public:
+    ModbusRTUComm(Stream& serial, int8_t dePin = -1, int8_t rePin = -1);
+    void begin(unsigned long baud, uint32_t config = SERIAL_8N1);
+    void setTimeout(unsigned long timeout);
+    ModbusRTUCommError readAdu(ModbusADU& adu);
+    void writeAdu(ModbusADU& adu);
+    void clearRxBuffer();
+
+  private:
+    Stream& _serial;
+    int8_t _dePin;
+    int8_t _rePin;
+    unsigned long _charTimeout;
+    unsigned long _frameTimeout;
+    unsigned long _postDelay = 0;
+    unsigned long _readTimeout = 0;
+};
+
+enum ModbusRTUMasterError : uint8_t {
+  MODBUS_RTU_MASTER_SUCCESS = 0,
+  MODBUS_RTU_MASTER_INVALID_ID = 1,
+  MODBUS_RTU_MASTER_INVALID_BUFFER = 2,
+  MODBUS_RTU_MASTER_INVALID_QUANTITY = 3,
+  MODBUS_RTU_MASTER_RESPONSE_TIMEOUT = 4,
+  MODBUS_RTU_MASTER_FRAME_ERROR = 5,
+  MODBUS_RTU_MASTER_CRC_ERROR = 6,
+  MODBUS_RTU_MASTER_UNKNOWN_COMM_ERROR = 7,
+  MODBUS_RTU_MASTER_UNEXPECTED_ID = 8,
+  MODBUS_RTU_MASTER_EXCEPTION_RESPONSE = 9,
+  MODBUS_RTU_MASTER_UNEXPECTED_FUNCTION_CODE = 10,
+  MODBUS_RTU_MASTER_UNEXPECTED_LENGTH = 11,
+  MODBUS_RTU_MASTER_UNEXPECTED_BYTE_COUNT = 12,
+  MODBUS_RTU_MASTER_UNEXPECTED_ADDRESS = 13,
+  MODBUS_RTU_MASTER_UNEXPECTED_VALUE = 14,
+  MODBUS_RTU_MASTER_UNEXPECTED_QUANTITY = 15
+};
+
+class ModbusRTUMaster {
+  public:
+    ModbusRTUMaster(Stream& serial, int8_t dePin = -1, int8_t rePin = -1);
+    void setTimeout(unsigned long timeout);
+    void begin(unsigned long baud, uint32_t config = SERIAL_8N1);
+
+    ModbusRTUMasterError readCoils(uint8_t id, uint16_t startAddress, bool buf[], uint16_t quantity);
+    ModbusRTUMasterError readDiscreteInputs(uint8_t id, uint16_t startAddress, bool buf[], uint16_t quantity);
+    ModbusRTUMasterError readHoldingRegisters(uint8_t id, uint16_t startAddress, uint16_t buf[], uint16_t quantity);
+    ModbusRTUMasterError readInputRegisters(uint8_t id, uint16_t startAddress, uint16_t buf[], uint16_t quantity);
+
+    ModbusRTUMasterError writeSingleCoil(uint8_t id, uint16_t address, bool value);
+    ModbusRTUMasterError writeSingleHoldingRegister(uint8_t id, uint16_t address, uint16_t value);
+    ModbusRTUMasterError writeMultipleCoils(uint8_t id, uint16_t startAddress, bool buf[], uint16_t quantity);
+    ModbusRTUMasterError writeMultipleHoldingRegisters(uint8_t id, uint16_t startAddress, uint16_t buf[], uint16_t quantity);
+
+    uint8_t getExceptionResponse();
+
+  private:
+    ModbusRTUComm _rtuComm;
+    uint8_t _exceptionResponse = 0;
+
+    ModbusRTUMasterError _readValues(uint8_t id, uint8_t functionCode, uint16_t startAddress, bool buf[], uint16_t quantity);
+    ModbusRTUMasterError _readValues(uint8_t id, uint8_t functionCode, uint16_t startAddress, uint16_t buf[], uint16_t quantity);
+    ModbusRTUMasterError _writeSingleValue(uint8_t id, uint8_t functionCode, uint16_t address, uint16_t value);
+
+    ModbusRTUMasterError _translateCommError(ModbusRTUCommError commError);
+
+};
+
+
+
 /**********************************************************************
  * Modbusnode class
  * 
diff --git a/ModbusADU.cpp b/ModbusADU.cpp
deleted file mode 100644
index b7752b2..0000000
--- a/ModbusADU.cpp
+++ /dev/null
@@ -1,153 +0,0 @@
-#include "ModbusADU.h"
-
-void ModbusADU::setTransactionId(uint16_t transactionId) {
-  _setRegister(tcp, 0, transactionId);
-}
-
-void ModbusADU::setProtocolId(uint16_t protocolId) {
-  _setRegister(tcp, 2, protocolId);
-}
-
-void ModbusADU::setLength(uint16_t length) {
-  if (length < 3 || length > 254) _setRegister(tcp, 4, 0);
-  else _setRegister(tcp, 4, length);
-}
-
-void ModbusADU::setUnitId(uint8_t unitId) {
-  tcp[6] = unitId;
-}
-
-void ModbusADU::setFunctionCode(uint8_t functionCode) {
-  pdu[0] = functionCode;
-}
-
-void ModbusADU::setDataRegister(uint8_t index, uint16_t value) {
-  _setRegister(data, index, value);
-}
-
-
-
-void ModbusADU::setRtuLen(uint16_t rtuLen) {
-  setLength(rtuLen - 2);
-}
-
-void ModbusADU::setTcpLen(uint16_t tcpLen) {
-  setLength(tcpLen - 6);
-}
-
-void ModbusADU::setPduLen(uint16_t pduLen) {
-  setLength(pduLen + 1);
-}
-
-void ModbusADU::setDataLen(uint16_t dataLen) {
-  setLength(dataLen + 2);
-}
-
-
-
-uint16_t ModbusADU::getTransactionId() {
-  return _getRegister(tcp, 0);
-}
-
-uint16_t ModbusADU::getProtocolId() {
-  return _getRegister(tcp, 2);
-}
-
-uint16_t ModbusADU::getLength() {
-  uint16_t length = _getRegister(tcp, 4);
-  if (length < 3 || length > 254) return 0;
-  else return length;
-}
-
-uint8_t ModbusADU::getUnitId() {
-  return tcp[6];
-}
-
-uint8_t ModbusADU::getFunctionCode() {
-  return pdu[0];
-}
-
-uint16_t ModbusADU::getDataRegister(uint8_t index) {
-  return _getRegister(data, index);
-}
-
-
-
-uint16_t ModbusADU::getRtuLen() {
-  uint16_t len = getLength();
-  if (len == 0) return 0;
-  else return len + 2;
-}
-
-uint16_t ModbusADU::getTcpLen() {
-  uint16_t len = getLength();
-  if (len == 0) return 0;
-  else return len + 6;
-}
-
-uint16_t ModbusADU::getPduLen() {
-  uint16_t len = getLength();
-  if (len == 0) return 0;
-  else return len - 1;
-}
-
-uint16_t ModbusADU::getDataLen() {
-  uint16_t len = getLength();
-  if (len == 0) return 0;
-  else return len - 2;
-}
-
-
-
-void ModbusADU::updateCrc() {
-  uint16_t len = getLength();
-  uint16_t crc = _calculateCrc(len);
-  rtu[len] = lowByte(crc);
-  rtu[len + 1] = highByte(crc);
-}
-
-bool ModbusADU::crcGood() {
-  uint16_t len = getLength();
-  uint16_t aduCrc = rtu[len] | (rtu[len + 1] << 8);
-  uint16_t calculatedCrc = _calculateCrc(len);
-  if (aduCrc == calculatedCrc) return true;
-  else return false;
-}
-
-
-
-void ModbusADU::prepareExceptionResponse(uint8_t exceptionCode) {
-  pdu[0] |= 0x80;
-  pdu[1] = exceptionCode;
-  setPduLen(2);
-}
-
-
-
-void ModbusADU::_setRegister(uint8_t *buf, uint16_t index, uint16_t value) {
-  buf[index] = highByte(value);
-  buf[index + 1] = lowByte(value);
-}
-
-uint16_t ModbusADU::_getRegister(uint8_t *buf, uint16_t index) {
-  return (buf[index] << 8) | buf[index + 1];
-}
-
-uint16_t ModbusADU::_calculateCrc(uint16_t len) {
-  uint16_t value = 0xFFFF;
-  for (uint16_t i = 0; i < len; i++) {
-    value ^= (uint16_t)rtu[i];
-    for (uint8_t j = 0; j < 8; j++) {
-      bool lsb = value & 1;
-      value >>= 1;
-      if (lsb == true) value ^= 0xA001;
-    }
-  }
-  return value;
-}
-
-
-
-uint16_t div8RndUp(uint16_t value) {
-  return (value + 7) >> 3;
-}
\ No newline at end of file
diff --git a/ModbusADU.h b/ModbusADU.h
deleted file mode 100644
index 2aa72d9..0000000
--- a/ModbusADU.h
+++ /dev/null
@@ -1,52 +0,0 @@
-#ifndef ModbusADU_h
-#define ModbusADU_h
-
-#include "Arduino.h"
-
-class ModbusADU {
-  public:
-    uint8_t *rtu = _adu + 6;
-    uint8_t *tcp = _adu;
-    uint8_t *pdu = _adu + 7;
-    uint8_t *data = _adu + 8;
-
-    void setTransactionId(uint16_t transactionId);
-    void setProtocolId(uint16_t protocolId);
-    void setLength(uint16_t length);
-    void setUnitId(uint8_t unitId);
-    void setFunctionCode(uint8_t functionCode);
-    void setDataRegister(uint8_t index, uint16_t value);
-
-    void setRtuLen(uint16_t rtuLen);
-    void setTcpLen(uint16_t tcpLen);
-    void setPduLen(uint16_t pduLen);
-    void setDataLen(uint16_t dataLen);
-
-    uint16_t getTransactionId();
-    uint16_t getProtocolId();
-    uint16_t getLength();
-    uint8_t getUnitId();
-    uint8_t getFunctionCode();
-    uint16_t getDataRegister(uint8_t index);
-
-    uint16_t getRtuLen();
-    uint16_t getTcpLen();
-    uint16_t getPduLen();
-    uint16_t getDataLen();
-
-    void updateCrc();
-    bool crcGood();
-
-    void prepareExceptionResponse(uint8_t exceptionCode);
-
-  private:
-    uint8_t _adu[262];
-    void _setRegister(uint8_t *buf, uint16_t index, uint16_t value);
-    uint16_t _getRegister(uint8_t *buf, uint16_t index);
-    uint16_t _calculateCrc(uint16_t len);
-    
-};
-
-uint16_t  div8RndUp(uint16_t value);
-
-#endif
\ No newline at end of file
diff --git a/ModbusRTUComm.cpp b/ModbusRTUComm.cpp
deleted file mode 100644
index 2abbe96..0000000
--- a/ModbusRTUComm.cpp
+++ /dev/null
@@ -1,98 +0,0 @@
-#include "ModbusRTUComm.h"
-
-ModbusRTUComm::ModbusRTUComm(Stream& serial, int8_t dePin, int8_t rePin) : _serial(serial) {
-  _dePin = dePin;
-  _rePin = rePin;
-}
-
-void ModbusRTUComm::begin(unsigned long baud, uint32_t config) {
-  unsigned long bitsPerChar;
-  switch (config) {
-    case SERIAL_8E2:
-    case SERIAL_8O2:
-      bitsPerChar = 12;
-      break;
-    case SERIAL_8N2:
-    case SERIAL_8E1:
-    case SERIAL_8O1:
-      bitsPerChar = 11;
-      break;
-    case SERIAL_8N1:
-    default:
-      bitsPerChar = 10;
-      break;
-  }
-  if (baud <= 19200) {
-    _charTimeout = (bitsPerChar * 2500000) / baud;
-    _frameTimeout = (bitsPerChar * 4500000) / baud;
-  }
-  else {
-    _charTimeout = (bitsPerChar * 1000000) / baud + 750;
-    _frameTimeout = (bitsPerChar * 1000000) / baud + 1750;
-  }
-  #if defined(ARDUINO_UNOR4_MINIMA) || defined(ARDUINO_UNOR4_WIFI) || defined(ARDUINO_GIGA) || (defined(ARDUINO_NANO_RP2040_CONNECT) && defined(ARDUINO_ARCH_MBED))
-  _postDelay = ((bitsPerChar * 1000000) / baud) + 2;
-  #endif
-  if (_dePin >= 0) {
-    pinMode(_dePin, OUTPUT);
-    digitalWrite(_dePin, LOW);
-  }
-  if (_rePin >= 0) {
-    pinMode(_rePin, OUTPUT);
-    digitalWrite(_rePin, LOW);
-  }
-  clearRxBuffer();
-}
-
-void ModbusRTUComm::setTimeout(unsigned long timeout) {
-  _readTimeout = timeout;
-}
-
-ModbusRTUCommError ModbusRTUComm::readAdu(ModbusADU& adu) {
-  adu.setRtuLen(0);
-  unsigned long startMillis = millis();
-  while (!_serial.available()) {
-    if (millis() - startMillis >= _readTimeout) return MODBUS_RTU_COMM_TIMEOUT;
-  }
-  uint16_t len = 0;
-  unsigned long startMicros = micros();
-  do {
-    if (_serial.available()) {
-      startMicros = micros();
-      adu.rtu[len] = _serial.read();
-      len++;
-    }
-  } while (micros() - startMicros <= _charTimeout && len < 256);
-  adu.setRtuLen(len);
-  while (micros() - startMicros < _frameTimeout);
-  if (_serial.available()) {
-    adu.setRtuLen(0);
-    return MODBUS_RTU_COMM_FRAME_ERROR;
-  }
-  if (!adu.crcGood()) {
-    adu.setRtuLen(0);
-    return MODBUS_RTU_COMM_CRC_ERROR;
-  }
-  return MODBUS_RTU_COMM_SUCCESS;
-}
-
-void ModbusRTUComm::writeAdu(ModbusADU& adu) {
-  adu.updateCrc();
-  if (_dePin >= 0) digitalWrite(_dePin, HIGH);
-  if (_rePin >= 0) digitalWrite(_rePin, HIGH);
-  _serial.write(adu.rtu, adu.getRtuLen());
-  _serial.flush();
-  delayMicroseconds(_postDelay);
-  if (_dePin >= 0) digitalWrite(_dePin, LOW);
-  if (_rePin >= 0) digitalWrite(_rePin, LOW);
-}
-
-void ModbusRTUComm::clearRxBuffer() {
-  unsigned long startMicros = micros();
-  do {
-    if (_serial.available() > 0) {
-      startMicros = micros();
-      _serial.read();
-    }
-  } while (micros() - startMicros < _frameTimeout);
-}
diff --git a/ModbusRTUComm.h b/ModbusRTUComm.h
deleted file mode 100644
index cae7234..0000000
--- a/ModbusRTUComm.h
+++ /dev/null
@@ -1,33 +0,0 @@
-#ifndef ModbusRTUComm_h
-#define ModbusRTUComm_h
-
-#include "Arduino.h"
-#include "ModbusADU.h"
-
-enum ModbusRTUCommError : uint8_t {
-  MODBUS_RTU_COMM_SUCCESS = 0,
-  MODBUS_RTU_COMM_TIMEOUT = 1,
-  MODBUS_RTU_COMM_FRAME_ERROR = 2,
-  MODBUS_RTU_COMM_CRC_ERROR = 3
-};
-
-class ModbusRTUComm {
-  public:
-    ModbusRTUComm(Stream& serial, int8_t dePin = -1, int8_t rePin = -1);
-    void begin(unsigned long baud, uint32_t config = SERIAL_8N1);
-    void setTimeout(unsigned long timeout);
-    ModbusRTUCommError readAdu(ModbusADU& adu);
-    void writeAdu(ModbusADU& adu);
-    void clearRxBuffer();
-
-  private:
-    Stream& _serial;
-    int8_t _dePin;
-    int8_t _rePin;
-    unsigned long _charTimeout;
-    unsigned long _frameTimeout;
-    unsigned long _postDelay = 0;
-    unsigned long _readTimeout = 0;
-};
-
-#endif
\ No newline at end of file
diff --git a/ModbusRTUMaster.cpp b/ModbusRTUMaster.cpp
deleted file mode 100644
index 897ce5a..0000000
--- a/ModbusRTUMaster.cpp
+++ /dev/null
@@ -1,216 +0,0 @@
-#include "ModbusRTUMaster.h"
-
-ModbusRTUMaster::ModbusRTUMaster(Stream& serial, int8_t dePin, int8_t rePin) : _rtuComm(serial, dePin, rePin) {
-  _rtuComm.setTimeout(500);
-}
-
-void ModbusRTUMaster::setTimeout(unsigned long timeout) {
-  _rtuComm.setTimeout(timeout);
-}
-
-void ModbusRTUMaster::begin(unsigned long baud, uint32_t config) {
-  _rtuComm.begin(baud, config);
-}
-
-
-
-ModbusRTUMasterError ModbusRTUMaster::readCoils(uint8_t id, uint16_t startAddress, bool buf[], uint16_t quantity) {
-  return _readValues(id, 1, startAddress, buf, quantity);
-}
-
-ModbusRTUMasterError ModbusRTUMaster::readDiscreteInputs(uint8_t id, uint16_t startAddress, bool buf[], uint16_t quantity) {
-  return _readValues(id, 2, startAddress, buf, quantity);
-}
-
-ModbusRTUMasterError ModbusRTUMaster::readHoldingRegisters(uint8_t id, uint16_t startAddress, uint16_t buf[], uint16_t quantity) {
-  return _readValues(id, 3, startAddress, buf, quantity);
-}
-
-ModbusRTUMasterError ModbusRTUMaster::readInputRegisters(uint8_t id, uint16_t startAddress, uint16_t buf[], uint16_t quantity) {
-  return _readValues(id, 4, startAddress, buf, quantity);
-}
-
-
-
-ModbusRTUMasterError ModbusRTUMaster::writeSingleCoil(uint8_t id, uint16_t address, bool value) {
-  return _writeSingleValue(id, 5, address, ((value) ? 0xFF00 : 0x0000));
-}
-
-ModbusRTUMasterError ModbusRTUMaster::writeSingleHoldingRegister(uint8_t id, uint16_t address, uint16_t value) {
-  return _writeSingleValue(id, 6, address, value);
-}
-
-
-
-ModbusRTUMasterError ModbusRTUMaster::writeMultipleCoils(uint8_t id, uint16_t startAddress, bool buf[], uint16_t quantity) {
-  const uint8_t functionCode = 15;
-  if (id > 247) return MODBUS_RTU_MASTER_INVALID_ID;
-  if (!buf) return MODBUS_RTU_MASTER_INVALID_BUFFER;
-  if (quantity == 0 || quantity > 1968) return MODBUS_RTU_MASTER_INVALID_QUANTITY;
-  ModbusADU adu;
-  uint16_t byteCount = div8RndUp(quantity);
-  adu.setUnitId(id);
-  adu.setFunctionCode(functionCode);
-  adu.setDataRegister(0, startAddress);
-  adu.setDataRegister(2, quantity);
-  adu.data[4] = byteCount;
-  for (uint16_t i = 0; i < quantity; i++) {
-    bitWrite(adu.data[5 + (i >> 3)], i & 7, buf[i]);
-  }
-  for (uint16_t i = quantity; i < (byteCount * 8); i++) {
-    bitClear(adu.data[5 + (i >> 3)], i & 7);
-  }
-  adu.setDataLen(5 + byteCount);
-  _rtuComm.writeAdu(adu);
-  if (id == 0) return MODBUS_RTU_MASTER_SUCCESS;
-  ModbusRTUCommError commError = _rtuComm.readAdu(adu);
-  if (commError) return _translateCommError(commError);
-  if (adu.getUnitId() != id) return MODBUS_RTU_MASTER_UNEXPECTED_ID;
-  if (adu.getFunctionCode() == (functionCode + 0x80)) {
-    _exceptionResponse = adu.data[0];
-    return MODBUS_RTU_MASTER_EXCEPTION_RESPONSE;
-  }
-  if (adu.getFunctionCode() != functionCode) return MODBUS_RTU_MASTER_UNEXPECTED_FUNCTION_CODE;
-  if (adu.getDataLen() != 4) return MODBUS_RTU_MASTER_UNEXPECTED_LENGTH;
-  if (adu.getDataRegister(0) != startAddress) return MODBUS_RTU_MASTER_UNEXPECTED_ADDRESS;
-  if (adu.getDataRegister(2) != quantity) return MODBUS_RTU_MASTER_UNEXPECTED_QUANTITY;
-  return MODBUS_RTU_MASTER_SUCCESS;
-}
-
-ModbusRTUMasterError ModbusRTUMaster::writeMultipleHoldingRegisters(uint8_t id, uint16_t startAddress, uint16_t buf[], uint16_t quantity) {
-  uint8_t functionCode = 16;
-  if (id > 247) return MODBUS_RTU_MASTER_INVALID_ID;
-  if (!buf) return MODBUS_RTU_MASTER_INVALID_BUFFER;
-  if (quantity == 0 || quantity > 123) return MODBUS_RTU_MASTER_INVALID_QUANTITY;
-  uint16_t byteCount = quantity * 2;
-  ModbusADU adu;
-  adu.setUnitId(id);
-  adu.setFunctionCode(functionCode);
-  adu.setDataRegister(0, startAddress);
-  adu.setDataRegister(2, quantity);
-  adu.data[4] = byteCount;
-  for (uint16_t i = 0; i < quantity; i++) {
-    adu.setDataRegister(5 + (i * 2), buf[i]);
-  }
-  adu.setDataLen(5 + byteCount);
-  _rtuComm.writeAdu(adu);
-  if (id == 0) return MODBUS_RTU_MASTER_SUCCESS;
-  ModbusRTUCommError commError = _rtuComm.readAdu(adu);
-  if (commError) return _translateCommError(commError);
-  if (adu.getUnitId() != id) return MODBUS_RTU_MASTER_UNEXPECTED_ID;
-  if (adu.getFunctionCode() == (functionCode + 0x80)) {
-    _exceptionResponse = adu.data[0];
-    return MODBUS_RTU_MASTER_EXCEPTION_RESPONSE;
-  }
-  if (adu.getFunctionCode() != functionCode) return MODBUS_RTU_MASTER_UNEXPECTED_FUNCTION_CODE;
-  if (adu.getDataLen() != 4) return MODBUS_RTU_MASTER_UNEXPECTED_LENGTH;
-  if (adu.getDataRegister(0) != startAddress) return MODBUS_RTU_MASTER_UNEXPECTED_ADDRESS;
-  if (adu.getDataRegister(2) != quantity) return MODBUS_RTU_MASTER_UNEXPECTED_QUANTITY;
-  return MODBUS_RTU_MASTER_SUCCESS;
-}
-
-
-
-uint8_t ModbusRTUMaster::getExceptionResponse() {
-  return _exceptionResponse;
-}
-
-
-
-ModbusRTUMasterError ModbusRTUMaster::_readValues(uint8_t id, uint8_t functionCode, uint16_t startAddress, bool buf[], uint16_t quantity) {
-  if (id < 1 || id > 247) return MODBUS_RTU_MASTER_INVALID_ID;
-  if (!buf) return MODBUS_RTU_MASTER_INVALID_BUFFER;
-  if (quantity == 0 || quantity > 2000) return MODBUS_RTU_MASTER_INVALID_QUANTITY;
-  ModbusADU adu;
-  adu.setUnitId(id);
-  adu.setFunctionCode(functionCode);
-  adu.setDataRegister(0, startAddress);
-  adu.setDataRegister(2, quantity);
-  adu.setDataLen(4);
-  _rtuComm.writeAdu(adu);
-  ModbusRTUCommError commError = _rtuComm.readAdu(adu);
-  if (commError) return _translateCommError(commError);
-  if (adu.getUnitId() != id) return MODBUS_RTU_MASTER_UNEXPECTED_ID;
-  if (adu.getFunctionCode() == (functionCode + 0x80)) {
-    _exceptionResponse = adu.data[0];
-    return MODBUS_RTU_MASTER_EXCEPTION_RESPONSE;
-  }
-  if (adu.getFunctionCode() != functionCode) return MODBUS_RTU_MASTER_UNEXPECTED_FUNCTION_CODE;
-  uint16_t byteCount = div8RndUp(quantity);
-  if (adu.getDataLen() != (1 + byteCount)) return MODBUS_RTU_MASTER_UNEXPECTED_LENGTH;
-  if (adu.data[0] != byteCount) return MODBUS_RTU_MASTER_UNEXPECTED_BYTE_COUNT;
-  for (uint16_t i = 0; i < quantity; i++) {
-    buf[i] = bitRead(adu.data[1 + (i >> 3)], i & 7);
-  }
-  return MODBUS_RTU_MASTER_SUCCESS;
-}
-
-ModbusRTUMasterError ModbusRTUMaster::_readValues(uint8_t id, uint8_t functionCode, uint16_t startAddress, uint16_t buf[], uint16_t quantity) {
-  if (id < 1 || id > 247) return MODBUS_RTU_MASTER_INVALID_ID;
-  if (!buf) return MODBUS_RTU_MASTER_INVALID_BUFFER;
-  if (quantity == 0 || quantity > 125) return MODBUS_RTU_MASTER_INVALID_QUANTITY;
-  ModbusADU adu;
-  adu.setUnitId(id);
-  adu.setFunctionCode(functionCode);
-  adu.setDataRegister(0, startAddress);
-  adu.setDataRegister(2, quantity);
-  adu.setDataLen(4);
-  _rtuComm.writeAdu(adu);
-  ModbusRTUCommError commError = _rtuComm.readAdu(adu);
-  if (commError) return _translateCommError(commError);
-  if (adu.getUnitId() != id) return MODBUS_RTU_MASTER_UNEXPECTED_ID;
-  if (adu.getFunctionCode() == (functionCode + 0x80)) {
-    _exceptionResponse = adu.data[0];
-    return MODBUS_RTU_MASTER_EXCEPTION_RESPONSE;
-  }
-  if (adu.getFunctionCode() != functionCode) return MODBUS_RTU_MASTER_UNEXPECTED_FUNCTION_CODE;
-  uint16_t byteCount = quantity * 2;
-  if (adu.getDataLen() != (1 + byteCount)) return MODBUS_RTU_MASTER_UNEXPECTED_LENGTH;
-  if (adu.data[0] != byteCount) return MODBUS_RTU_MASTER_UNEXPECTED_BYTE_COUNT;
-  for (uint16_t i = 0; i < quantity; i++) {
-    buf[i] = adu.getDataRegister(1 + (i * 2));
-  }
-  return MODBUS_RTU_MASTER_SUCCESS;
-}
-
-ModbusRTUMasterError ModbusRTUMaster::_writeSingleValue(uint8_t id, uint8_t functionCode, uint16_t address, uint16_t value) {
-  if (id > 247) return MODBUS_RTU_MASTER_INVALID_ID;
-  ModbusADU adu;
-  adu.setUnitId(id);
-  adu.setFunctionCode(functionCode);
-  adu.setDataRegister(0, address);
-  adu.setDataRegister(2, value);
-  adu.setDataLen(4);
-  _rtuComm.writeAdu(adu);
-  if (id == 0) return MODBUS_RTU_MASTER_SUCCESS;
-  ModbusRTUCommError commError = _rtuComm.readAdu(adu);
-  if (commError) return _translateCommError(commError);
-  if (adu.getUnitId() != id) return MODBUS_RTU_MASTER_UNEXPECTED_ID;
-  if (adu.getFunctionCode() == (functionCode + 0x80)) {
-    _exceptionResponse = adu.data[0];
-    return MODBUS_RTU_MASTER_EXCEPTION_RESPONSE;
-  }
-  if (adu.getFunctionCode() != functionCode) return MODBUS_RTU_MASTER_UNEXPECTED_FUNCTION_CODE;
-  if (adu.getDataLen() != 4) return MODBUS_RTU_MASTER_UNEXPECTED_LENGTH;
-  if (adu.getDataRegister(0) != address) return MODBUS_RTU_MASTER_UNEXPECTED_ADDRESS;
-  if (adu.getDataRegister(2) != value) return MODBUS_RTU_MASTER_UNEXPECTED_VALUE;
-  return MODBUS_RTU_MASTER_SUCCESS;
-}
-
-
-
-ModbusRTUMasterError ModbusRTUMaster::_translateCommError(ModbusRTUCommError commError) {
-  switch (commError) {
-    case MODBUS_RTU_COMM_SUCCESS:
-      return MODBUS_RTU_MASTER_SUCCESS;
-    case MODBUS_RTU_COMM_TIMEOUT:
-      return MODBUS_RTU_MASTER_RESPONSE_TIMEOUT;
-    case MODBUS_RTU_COMM_FRAME_ERROR:
-      return MODBUS_RTU_MASTER_FRAME_ERROR;
-    case MODBUS_RTU_COMM_CRC_ERROR:
-      return MODBUS_RTU_MASTER_CRC_ERROR;
-    default:
-      return MODBUS_RTU_MASTER_UNKNOWN_COMM_ERROR;
-  }
-}
-
diff --git a/ModbusRTUMaster.h b/ModbusRTUMaster.h
deleted file mode 100644
index d9193c3..0000000
--- a/ModbusRTUMaster.h
+++ /dev/null
@@ -1,57 +0,0 @@
-#ifndef ModbusRTUMaster_h
-#define ModbusRTUMaster_h
-
-#include "Arduino.h"
-#include "ModbusADU.h"
-#include "ModbusRTUComm.h"
-
-enum ModbusRTUMasterError : uint8_t {
-  MODBUS_RTU_MASTER_SUCCESS = 0,
-  MODBUS_RTU_MASTER_INVALID_ID = 1,
-  MODBUS_RTU_MASTER_INVALID_BUFFER = 2,
-  MODBUS_RTU_MASTER_INVALID_QUANTITY = 3,
-  MODBUS_RTU_MASTER_RESPONSE_TIMEOUT = 4,
-  MODBUS_RTU_MASTER_FRAME_ERROR = 5,
-  MODBUS_RTU_MASTER_CRC_ERROR = 6,
-  MODBUS_RTU_MASTER_UNKNOWN_COMM_ERROR = 7,
-  MODBUS_RTU_MASTER_UNEXPECTED_ID = 8,
-  MODBUS_RTU_MASTER_EXCEPTION_RESPONSE = 9,
-  MODBUS_RTU_MASTER_UNEXPECTED_FUNCTION_CODE = 10,
-  MODBUS_RTU_MASTER_UNEXPECTED_LENGTH = 11,
-  MODBUS_RTU_MASTER_UNEXPECTED_BYTE_COUNT = 12,
-  MODBUS_RTU_MASTER_UNEXPECTED_ADDRESS = 13,
-  MODBUS_RTU_MASTER_UNEXPECTED_VALUE = 14,
-  MODBUS_RTU_MASTER_UNEXPECTED_QUANTITY = 15
-};
-
-class ModbusRTUMaster {
-  public:
-    ModbusRTUMaster(Stream& serial, int8_t dePin = -1, int8_t rePin = -1);
-    void setTimeout(unsigned long timeout);
-    void begin(unsigned long baud, uint32_t config = SERIAL_8N1);
-
-    ModbusRTUMasterError readCoils(uint8_t id, uint16_t startAddress, bool buf[], uint16_t quantity);
-    ModbusRTUMasterError readDiscreteInputs(uint8_t id, uint16_t startAddress, bool buf[], uint16_t quantity);
-    ModbusRTUMasterError readHoldingRegisters(uint8_t id, uint16_t startAddress, uint16_t buf[], uint16_t quantity);
-    ModbusRTUMasterError readInputRegisters(uint8_t id, uint16_t startAddress, uint16_t buf[], uint16_t quantity);
-
-    ModbusRTUMasterError writeSingleCoil(uint8_t id, uint16_t address, bool value);
-    ModbusRTUMasterError writeSingleHoldingRegister(uint8_t id, uint16_t address, uint16_t value);
-    ModbusRTUMasterError writeMultipleCoils(uint8_t id, uint16_t startAddress, bool buf[], uint16_t quantity);
-    ModbusRTUMasterError writeMultipleHoldingRegisters(uint8_t id, uint16_t startAddress, uint16_t buf[], uint16_t quantity);
-
-    uint8_t getExceptionResponse();
-
-  private:
-    ModbusRTUComm _rtuComm;
-    uint8_t _exceptionResponse = 0;
-
-    ModbusRTUMasterError _readValues(uint8_t id, uint8_t functionCode, uint16_t startAddress, bool buf[], uint16_t quantity);
-    ModbusRTUMasterError _readValues(uint8_t id, uint8_t functionCode, uint16_t startAddress, uint16_t buf[], uint16_t quantity);
-    ModbusRTUMasterError _writeSingleValue(uint8_t id, uint8_t functionCode, uint16_t address, uint16_t value);
-
-    ModbusRTUMasterError _translateCommError(ModbusRTUCommError commError);
-
-};
-
-#endif