The goal is to simply listen to the data stream that my laser diameter sensor is putting out on RS-485. (2400 BAUD, 8 data, No parity, 1 Stop) I have tested the _exact_ same RS-485 board setup on a Mega just to be certain everything external to the F446RE is correct and fully functional. I even tried exchanging the Rx and Tx pins to be sure that wasn't the issue. No bueno.
I'm sure it is something simple that I have foolishly overlooked.
Here is my code:
Code: Select all
/*
* Version 01 RS485 Laser RS-484 reading test program (with LCD added)
* Bill Dube, Nov 24, 2024
* Nucleo F446RE Ver 01
*
*/
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
HardwareSerial Serial1(USART1); //D10/(PB6) =TX1 PB7 = RX1
#define VER 01
#define SERIAL_XMT 2 // DE control pin on RS 485 board
#define SERIAL_RCV 3 // RE control pin on RS 485 board
#define LCD_SCL PB8 // I2C clock pin
#define LCD_SDA PB9 // I2C data pin
LiquidCrystal_I2C lcd(0x27,16,2); // set the LCD address to 0x27 for a 16 chars and 2 line display
byte getdata;
int ByteCount;
long LaserDiaReadingI =0;
float LaserDiaReadingF;
String DigitString, ReadingString;
unsigned long int TimeNow;
float SecondsElapsed;
void setup() {
lcd.init(); // initialize the lcd
lcd.backlight();
//Using Serial1 Port for RS485,
// Pin PB6 (D10) TX Connected to pin DI on RS-485 board
// Pin PB7 RX Connected to pin R0 on RS-485 board
// (This is the opposite to what is typically shown in tutorials, but this indeed is what works.)
Serial1.begin(2400); // Serial1 port = 2400 baud, 8 data, No parity, 1 stop
// Serial.begin(115200); // Start serial monitor port when running this on a Mega
// Pin D2 connected to pin DE on rs485 board
// Pin D3 connected to pin RE on rs485 board
pinMode(SERIAL_XMT, OUTPUT);//DE Controling pin of RS-485
pinMode(SERIAL_RCV, OUTPUT);//RE Controling pin of RS-485
// Set DE and RE to logic LOW
digitalWrite(SERIAL_XMT,LOW);//DE=LOW Receive Enabled M1
digitalWrite(SERIAL_RCV,LOW);//RE=LOW Receive Enabled M1
delay(100); // Give a bit of time for board to get its serail pins sorted...
lcd.setCursor(0,0);
lcd.print("RS485 Ver= ");
lcd.println(VER);
delay(1000); // Pause to leave the starting splash up on the monitor for a second...
TimeNow = millis();
} // end setup()
void loop() {
getdata=0;
if(Serial1.available()){ //if there is a byte is available on the RS485
getdata=Serial1.read();
if (getdata == 0xF1) { // We have the beginning of a reading
ByteCount=1; // Reset the byte counter
// lcd.setCursor(0,0); // Time stamp stuff for using with Mega and serial monitor
// lcd.print("Time=");
// SecondsElapsed = (millis() - TimeNow) / 1000.0; // divide by a float to force the type conversion
// lcd.print(SecondsElapsed,3);
lcd.setCursor(0,0); // Row 1 col 1
lcd.print("Laser Reading = ");
lcd.setCursor(0,1); // Row 1 col 2
lcd.print(" "); // clear it out with blanks
lcd.setCursor(0,1); // Row 1 col 2
lcd.print(LaserDiaReadingF, 3); // Write what we get back from the laser
ReadingString =String(""); // Clear out for a new reading
}
else
{
DigitString =String(""); // Clear out the digit string
if (getdata < 16){
DigitString =String(0,HEX);
}
//Serial.print(getdata,HEX);
DigitString +=String(getdata,HEX);
if (ByteCount <=3 ) { // only save first 3 bytes
ReadingString = DigitString + ReadingString; // Put the latest data in the _front_
ByteCount++; // increment the byte counter
}
if (ByteCount == 4) {
LaserDiaReadingI = ReadingString.toInt();
LaserDiaReadingF = LaserDiaReadingI / 1000.0;
ByteCount++;
}
}
} // if Serial1 avalible
} // end loop()
