RS485_Sensor_Node_V1.0__SKU_DFR0233_-DFRobot

/*
# The Sample code for test the data of Analogue_Test and SHT1X Module

 # Editor : Lisper
 # Date   : 2013.12.9
 # Ver    : 1.3
 # Product: Analogue_Test and SHT1X Module
 # SKU    : DFR0233

 # Description:
 # Read the Analog value and the data of humidity & temperature

 # Hardwares:
 1. Arduino UNO
 2. IO Expansion Shield V5
 3. Analogue_Test and SHT1X Module

 # Interface: RS485
 # Note: Connect the Analogue_Test and SHT1X Module with IO Expansion Shield V5 through RS485
 Set the address of the module in manual,range from 0x02 to 0x7F,take effect after 30 seconds
*/

#define uint    unsigned  int
#define uchar   unsigned  char
#define ulong   unsigned  long
#define addr  0x02     //set address of the device for 0x02
uchar cmd[50];
uchar receive_ACK[100];
int EN = 2;

#if defined(ARDUINO) && ARDUINO >= 100
#include "Arduino.h"
#define printByte(args) Serial.write(args)
#define printlnByte(args)  Serial.write(args),Serial.println()
#else
#include "WProgram.h"
#define printByte(args) Serial.print(args,BYTE)
#define printlnByte(args)  Serial.println(args,BYTE)
#endif

void setup() {
  Serial.begin(9600);
  pinMode(2, OUTPUT); // TTL -> RS485 chip driver pin
}

void loop() {
  static ulong timepoint = 0;
  if (millis() - timepoint > 1000) {
    read_command();
    timepoint = millis();
  }
  if (Serial.available() > 0) data_return();

  //  delay(1000);

}

/************************Send command to Analogue_Test and SHT1X Module*************************/
void read_command()
{
  int i;
  char sum_cmd = 0;
  digitalWrite(EN, HIGH); // Turn the drvier pin to HIGH -> Turn on code transmitting mode for the RS485 interface
  // Turn the driver pin to LOW  -> Turn on reading mode for the RS485 interface
  delay(10);
  cmd[0] = 0x55;
  cmd[1] = 0xaa;
  cmd[2] = addr;
  cmd[3] = 0x00;
  cmd[4] = 0x21;
  for (i = 0; i < 5; i++) {
    sum_cmd += cmd[i];
  }
  cmd[5] = sum_cmd;

  for (i = 0; i < 6; i++) {

    printByte(cmd[i]);// command send to device
#if defined(ARDUINO) && ARDUINO >= 100
    Serial.flush();// complete the transmission of outgoing serial data
#endif
    delay(10);
  }
  digitalWrite(EN, LOW);
}
/************Feedback data of the Analog value and humidity & temperature ************/\



void data_return()
{
  digitalWrite(EN, LOW); // Turn the driver pin to LOW  -> Turn on reading mode for the RS485 interface
  delay(10);
  int i = 0;

  unsigned long timer = millis();

  while (true) {
    if (Serial.available()) {
      receive_ACK[i] = Serial.read();
      i++;
    }
    if (millis() - timer > 100) {
      break;
      Serial.println("Finish reading!");
    }
  }
  print_data () ;


  /*************************************************************************/
  // Display the original data

  //        for(int j = 0; j < 26; j++){
  //                Serial.print(receive_ACK[j],HEX); // return command
  //                Serial.print(" ");
  //        }
  //        Serial.println(" ");
}

void show_0x21_command(void)
{
  sht1x_data();
  Analog_test_data();

}

/************Deal with datas from Sht1x humidity & temperature sensor************/

void sht1x_data()
{
  uint humidity;
  uint temperature;
  humidity =  receive_ACK[7] * 256 + receive_ACK[8];
  temperature = receive_ACK[9] * 256 + receive_ACK[10];
  Serial.print("H:");
  Serial.print(humidity / 10, DEC);
  Serial.print("  ");
  Serial.print("T:");
  Serial.println(temperature / 10, DEC);
}

/********************Deal with datas from 6 Analog Sensors****************/
void Analog_test_data()
{
  char register_addr;
  uint  Analog_data;
  register_addr = 13;
  Serial.print("Analog Value:");
  for (int n = 1; n < 7; n++) {
    Analog_data = receive_ACK[register_addr] * 256 + receive_ACK[register_addr + 1];
    register_addr = register_addr + 2;
    Serial.print(Analog_data, DEC);
    Serial.print(" ");
  }
  Serial.println(" ");
  delay(1000);
}

/*************************** by lisper *********************************/
//print humidity and temperature
void print_data () {
  if (checksum ()) {        // if check sum is right
    Serial.println ();
    float humidity = read_uint8_t (receive_ACK, 7) / 10.0;
    Serial.print ("humidity=");
    Serial.println (humidity, 2);

    float temperature = (read_uint8_t (receive_ACK, 9) / 10.0);
    Serial.print ("temperature=");
    Serial.println (temperature, 2);
  }
  else {
    Serial.print ("\ncheck sum error! sum=");
    Serial.println (getsum_add (receive_ACK, 25), HEX);
  }
}

//if check sum is ok
boolean checksum () {
  uint8_t checksum = getsum_add (receive_ACK, 25);
  if (checksum == receive_ACK[25])
    return true;
  else
    return false;
}

//read 2 byte to uint16_t
uint16_t read_uint8_t (uint8_t *buffer, uint8_t sub) {        // Big-Endian, first byte is high byte
  return ((uint16_t)(buffer[sub]) << 8) + buffer[sub + 1];
}

//get check sum, add from 0 to length-1
uint8_t getsum_add (uint8_t *buffer, uint8_t length) {
  uint8_t sum;
  for (int i = sum = 0; i < length; i++) {
    sum += buffer[i];
  }
  return sum;
}
/*******************************************************************************/