Graphical LCD Backpack

This component has a library to perform some its funcionality, but it has a worse API than calling the serial backbones.

For example, the library calls directly in most of the endpoints to the same serial method:

void LCD::printStr(char Str[78])//26 characters is the length of one line on the LCD
{
    serial.print(Str);
    //if you need to print longer strings, change the size of this array here and in the .h file
}
//-------------------------------------------------------------------------------------------
void LCD::printNum(int num)//can't convert ints to strings so this is just for printing ints
{
    serial.print(num);
}
//-------------------------------------------------------------------------------------------
void LCD::nextLine()//prints new line
{
    serial.println();
}

And the method nextLine doesn't even work, as the board doesn't support "\n".

Instead, our program was base on the libarary to get the operations and used serial to program it better.

Finally, this example was made for an arduino mega, as it supports more than one serial so that the program could be debuged in the computer.

DataSheets Technical Docs

Library

Library: SparkFun Graphic LCD Serial Backpack

How it works

You give the information of the pointer to start writing and, then, give the string.

Connexions

The Rx of the LCD must be the Tx of the board and the other way around.

Example

#include "DHT.h"

#define maxX 127//159 
#define maxY 63 //127


DHT dht(22, DHT11);

/* OUR FUNCTIONS */
void setX(byte posX) //0-127 or 0-159 pixels
{
  //Set the X position 
  Serial1.write(0x7C);
  Serial1.write(0x18);//CTRL x
  Serial1.write(posX);
}

//-------------------------------------------------------------------------------------------
void clearScreen()
{
  //clears the screen, you will use this a lot!
  Serial1.write(0x7C);
  Serial1.write((byte)0); //CTRL @
  //can't send LCD.write(0) or LCD.write(0x00) because it's interprestted as a NULL
}
void setY(byte posY)//0-63 or 0-127 pixels
{
  //Set the y position 
  Serial1.write(0x7C);
  Serial1.write(0x19);//CTRL y
  Serial1.write(posY);

}

void setHome() {
  setX((byte)0);
  setY((byte)0);
}


void setup() {
  dht.begin();
  Serial1.begin(115200);
  delay(1200);

  clearScreen();
  setHome();//set the cursor back to 0,0.
  delay(10);

  Serial1.print("Starting dataproducer1");
  delay(1000);

}

void tempAndHumidity(float tempC, float humidity, float heatIndex) {
  //This function shows how you could read the data from a temerature and humidity
  //sensor and then print that data to the Graphic LCD.

  clearScreen();
  //these could be varaibles instead of static numbers

  Serial1.print("Temperature = ");
  Serial1.print(tempC);
  Serial1.print("C ");
  Serial1.print("Humidity = ");
  Serial1.print(humidity);
  Serial1.print("%    ");
  Serial1.print("Heat index = ");
  Serial1.print(heatIndex);
  Serial1.print("C ");

}


void loop() {
  // put your main code here, to run repeatedly:
  // Reading temperature or humidity takes about 250 milliseconds!
  // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
  float h = dht.readHumidity();
  // Read temperature as Celsius (the default)
  float t = dht.readTemperature();
  if (isnan(h) || isnan(t)) {
    Serial.println(F("Failed to read from DHT sensor!"));

  } else {
    float hic = dht.computeHeatIndex(t, h, false);
    tempAndHumidity(t, h, hic);
  }
  // Compute heat index in Celsius (isFahreheit = false)
  delay(2500);

}