Hello, I have a project to make a display to monitor data from a PLC. I'm using Arduino Nano, 128x64 OLED, and TTL to RS485 (MAX485). The libraries I use are Adafruit_SSD1306.h and SimpleModbusMaster.h. Communication is smooth when I use the SimpleModbusMaster.h Library. But when I combine programs using OLED. Communication does not occur in OLED or PLC. I'm using I2C on OLED, and SoftwareSerial in pin (2,3) in library SimpleModbusMaster.h. Here's the code I use and the wiring. Is there any suggestion so that OLED and Modbus communication run smoothly?
#include "SimpleModbusMaster.h"
#include "ConvIntToFloat.h"
#include <Wire.h>
#include <Adafruit_SSD1306.h> //Legacy include:include "SSD1306.h"
#include <Adafruit_GFX.h>
#include <Fonts/Roboto_Light_14.h>
Adafruit_SSD1306 lcd(128, 64, &Wire, -1);
#define connection_error_led 13
#define baud 38400
#define timeout 2000
#define polling 200
#define retry_count 10
#define TxEnablePin 8
float rh = 0.0, temp = 0.0;
int Flag = 1;
String Flag1;
//This is the easiest way to create new packets, Add as many as you want. TOTAL_NO_OF_PACKETS, is automatically updated.
enum {
PACKET1,
PACKET2,
// leave this last entry
TOTAL_NO_OF_PACKETS
};
//Create an array of Packets for modbus_update()
Packet packets[TOTAL_NO_OF_PACKETS];
packetPointer packet1 = &packets[PACKET1];
packetPointer packet2 = &packets[PACKET2];
unsigned int data485[4];
unsigned int data485write[1];
unsigned long last_toggle = 0;
unsigned long previousMillis = 0;
void setup() {
Serial.begin(38400);
delay(100);
lcd.begin(SSD1306_SWITCHCAPVCC, 0x3c);
//===Read 4 registers starting at address 8983===//
packet1->id = 1;
packet1->function = READ_HOLDING_REGISTERS;
packet1->address = 8983;
packet1->no_of_registers = 2;
packet1->register_array = data485;
//===Write the 1 registers to the PLC starting at address 8985===//
packet2->id = 1;
packet2->function = PRESET_MULTIPLE_REGISTERS;
packet2->address = 8985;
packet2->no_of_registers = 1;
packet2->register_array = data485write;
//Initialize communication settings etc...
modbus_configure(baud, timeout, polling, retry_count, TxEnablePin, packets, TOTAL_NO_OF_PACKETS);
}
void loop() {
unsigned long currentMillis = millis();
//USE For Read Data Register
if (currentMillis - previousMillis >= 200)
{
previousMillis = currentMillis;
Serial.println("Masuk Case 1");
unsigned int connection_status = modbus_update(packets);
rh = InttoFloat(data485[1], data485[0]);
temp = InttoFloat(data485[3], data485[2]);
Serial.println(rh);
Serial.println(temp);
Serial.print("Nilai Modbus Update = ");
Serial.println(connection_status);
}
//Use for show data to OLED
previousMillis = currentMillis;
Serial.println("Masuk Case 2");
lcd.clearDisplay();
lcd.setFont(&Roboto_Light_14);
lcd.setTextColor(WHITE);
lcd.setCursor(10, 11);
lcd.print("AHU Condition");
lcd.setCursor(0, 35);
lcd.print("Temp");
lcd.setCursor(40, 35);
lcd.print(":");
lcd.setCursor(47, 35);
lcd.print(String(temp));
lcd.setCursor(0, 50);
lcd.print("RH");
lcd.setCursor(40, 50);
lcd.print(":");
lcd.setCursor(47, 50);
lcd.print(String(rh));
lcd.display();
}
