ArduinoModbus getting to work

main.cpp

//Test code for modbus server (slave)

#include <Arduino.h>
#include <ArduinoRS485.h>
#include <ArduinoModbus.h>
#include "ntc.h"

#define D_RELAY_1 7
#define S_RELAY_1 10
#define PULLUP_OUT_1 11
#define TEMP_1  A0
#define BUTTON1 19
#define BUTTON2 20
#define BUTTON3 21
#define DIODE0  0
#define DIODE1  1  

NTC temp_sensor(TEMP_1, 3.3, 4000);

void setup()
{
  // put your setup code here, to run once:
  pinMode(LED_BUILTIN, OUTPUT);
  pinMode(D_RELAY_1, OUTPUT);
  pinMode(S_RELAY_1, OUTPUT);
  pinMode(PULLUP_OUT_1, OUTPUT);
  pinMode(TEMP_1, INPUT);
  pinMode(DIODE0, OUTPUT);
  pinMode(DIODE1, OUTPUT);

  //Serial2.begin(19200);
  if (!ModbusRTUServer.begin(1, 115200))
  {
    while (1)
      ;
  }
  uint8_t ret = ModbusRTUServer.configureCoils(0x0000, 4);
  while (!ret)
  {
    digitalWrite(LED_BUILTIN, HIGH);
    delay(500);
    digitalWrite(LED_BUILTIN, LOW);
    delay(500);
  }
  ret = ModbusRTUServer.configureHoldingRegisters(0, 5);
  while (!ret)
  {
    digitalWrite(LED_BUILTIN, HIGH);
    delay(500);
    digitalWrite(LED_BUILTIN, LOW);
    delay(500);
  }
  ret = ModbusRTUServer.configureInputRegisters(0, 1);
  while (!ret)
  {
    digitalWrite(LED_BUILTIN, HIGH);
    delay(500);
    digitalWrite(LED_BUILTIN, LOW);
    delay(500);
  }
  ret = ModbusRTUServer.configureDiscreteInputs(0, 3);
  while (!ret)
  {
    digitalWrite(LED_BUILTIN, HIGH);
    delay(500);
    digitalWrite(LED_BUILTIN, LOW);
    delay(500);
  }
}

void loop()
{
  // put your main code here, to run repeatedly:
  static unsigned long prev = 0;
  static uint8_t led_state = 0;
  static uint8_t d_relay_state = 0;
  static uint8_t s_relay_state = 0;
  static uint8_t pullup_out_state = 0;
  float temp_val;
  static uint8_t btn1, btn2, btn3;
  static uint16_t diode0_pwm, diode1_pwm;
  ModbusRTUServer.poll();
  led_state = ModbusRTUServer.coilRead(0);
  d_relay_state = ModbusRTUServer.coilRead(1);
  s_relay_state = ModbusRTUServer.coilRead(2);
  pullup_out_state = ModbusRTUServer.coilRead(3);
  digitalWrite(LED_BUILTIN, led_state);
  digitalWrite(D_RELAY_1, d_relay_state);
  digitalWrite(S_RELAY_1, s_relay_state);
  digitalWrite(PULLUP_OUT_1, pullup_out_state);
  //temp_val = analogRead(TEMP_1);
  // ModbusRTUServer.holdingRegisterWrite(0, temp_val);
  // ModbusRTUServer.holdingRegisterWrite(1, 1234);
  temp_val = temp_sensor.getAvgTemperature(64);
  temp_val += 0.01;
  ModbusRTUServer.inputRegisterWrite(0, temp_val);
  btn1 = digitalRead(BUTTON1);
  btn2 = digitalRead(BUTTON2);
  btn3 = digitalRead(BUTTON3);
  ModbusRTUServer.discreteInputWrite(0, btn1);
  ModbusRTUServer.discreteInputWrite(1, btn2);
  ModbusRTUServer.discreteInputWrite(2, btn3);
  diode0_pwm = ModbusRTUServer.holdingRegisterRead(0);
  diode1_pwm = ModbusRTUServer.holdingRegisterRead(1);
  analogWrite(DIODE0, diode0_pwm);
  analogWrite(DIODE1, diode1_pwm);

}

pins_arduino.h

#pragma once
#include <macros.h>
#include <stdint.h>

#ifndef __PINS_ARDUINO__
#define __PINS_ARDUINO__

#ifdef __cplusplus
extern "C" unsigned int PINCOUNT_fn();
#endif

// Pin count
// ----
#define PINS_COUNT           (PINCOUNT_fn())
#define NUM_DIGITAL_PINS     (30u)
#define NUM_ANALOG_INPUTS    (4u)
#define NUM_ANALOG_OUTPUTS   (0u)

extern PinName digitalPinToPinName(pin_size_t P);

// LEDs
// ----
#define PIN_LED     (25u)
#define LED_BUILTIN PIN_LED

// Analog pins
// -----------
#define PIN_A0 (26u)
#define PIN_A1 (27u)
#define PIN_A2 (28u)
#define PIN_A3 (29u)

static const uint8_t A0  = PIN_A0;
static const uint8_t A1  = PIN_A1;
static const uint8_t A2  = PIN_A2;
static const uint8_t A3  = PIN_A3;

#define ADC_RESOLUTION 12

// Serial
#define PIN_SERIAL_TX (0ul)
#define PIN_SERIAL_RX (1ul)

#define PIN_SERIAL2_TX (16ul)
#define PIN_SERIAL2_RX (17ul)


// SPI
#define PIN_SPI_MISO  (16u)
#define PIN_SPI_MOSI  (19u)
#define PIN_SPI_SCK   (18u)
#define PIN_SPI_SS    (17u)

static const uint8_t SS   = PIN_SPI_SS;   // SPI Slave SS not used. Set here only for reference.
static const uint8_t MOSI = PIN_SPI_MOSI;
static const uint8_t MISO = PIN_SPI_MISO;
static const uint8_t SCK  = PIN_SPI_SCK;

// Wire
#define PIN_WIRE_SDA        (4u)
#define PIN_WIRE_SCL        (5u)

#define SERIAL_HOWMANY		2
#define SERIAL1_TX			(digitalPinToPinName(PIN_SERIAL_TX))
#define SERIAL1_RX			(digitalPinToPinName(PIN_SERIAL_RX))
#define SERIAL2_TX          (digitalPinToPinName(PIN_SERIAL2_TX))
#define SERIAL2_RX          (digitalPinToPinName(PIN_SERIAL2_RX))

#define SERIAL_CDC			1
#define HAS_UNIQUE_ISERIAL_DESCRIPTOR
#define BOARD_VENDORID		0x2e8a
#define BOARD_PRODUCTID		0x00c0
#define BOARD_NAME			"RaspberryPi Pico"

uint8_t getUniqueSerialNumber(uint8_t* name);
void _ontouch1200bps_();

#define SPI_HOWMANY		(1)
#define SPI_MISO		(digitalPinToPinName(PIN_SPI_MISO))
#define SPI_MOSI		(digitalPinToPinName(PIN_SPI_MOSI))
#define SPI_SCK			(digitalPinToPinName(PIN_SPI_SCK))

#define WIRE_HOWMANY	(1)
#define I2C_SDA			(digitalPinToPinName(PIN_WIRE_SDA))
#define I2C_SCL			(digitalPinToPinName(PIN_WIRE_SCL))

#define digitalPinToPort(P)		(digitalPinToPinName(P)/32)

#define SERIAL_PORT_USBVIRTUAL      SerialUSB
#define SERIAL_PORT_MONITOR         SerialUSB
#define SERIAL_PORT_HARDWARE        Serial1
#define SERIAL_PORT_HARDWARE_OPEN   Serial1
#define SERIAL_PORT_HARDWARE2       Serial2

#define USB_MAX_POWER	(500)

#endif //__PINS_ARDUINO__

RS485.cpp

.
.
.
RS485Class RS485(SERIAL_PORT_HARDWARE2, RS485_DEFAULT_TX_PIN, RS485_DEFAULT_DE_PIN, RS485_DEFAULT_RE_PIN);

RS485.h

/*
  This file is part of the ArduinoRS485 library.
  Copyright (c) 2018 Arduino SA. All rights reserved.

  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.

  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.

  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
*/

#ifndef _RS485_H_INCLUDED
#define _RS485_H_INCLUDED

#include <Arduino.h>

#ifdef PIN_SERIAL2_TX
#define RS485_DEFAULT_TX_PIN PIN_SERIAL2_TX
#else
#define RS485_DEFAULT_TX_PIN 16
#endif

#ifdef __AVR__
#define RS485_DEFAULT_DE_PIN 2
#define RS485_DEFAULT_RE_PIN -1
#else
#define RS485_DEFAULT_DE_PIN 18
#define RS485_DEFAULT_RE_PIN 18
#endif


#define RS485_DEFAULT_PRE_DELAY 100
#define RS485_DEFAULT_POST_DELAY 5000 //this delay resolve timout/invalid checksum error

class RS485Class : public Stream {
  public:
    RS485Class(HardwareSerial& hwSerial, int txPin, int dePin, int rePin);

    virtual void begin(unsigned long baudrate);
    virtual void begin(unsigned long baudrate, uint16_t config);
    virtual void begin(unsigned long baudrate, int predelay, int postdelay);
    virtual void begin(unsigned long baudrate, uint16_t config, int predelay, int postdelay);
    virtual void end();
    virtual int available();
    virtual int peek();
    virtual int read(void);
    virtual void flush();
    virtual size_t write(uint8_t b);
    using Print::write; // pull in write(str) and write(buf, size) from Print
    virtual operator bool();

    void beginTransmission();
    void endTransmission();
    void receive();
    void noReceive();

    void sendBreak(unsigned int duration);
    void sendBreakMicroseconds(unsigned int duration);

    void setPins(int txPin, int dePin, int rePin);

    void setDelays(int predelay, int postdelay);

  private:
    HardwareSerial* _serial;
    int _txPin;
    int _dePin;
    int _rePin;
    int _predelay = 0;
    int _postdelay = 0;

    bool _transmisionBegun;
    unsigned long _baudrate;
    uint16_t _config;
};

extern RS485Class RS485;

#endif