Arduino RF Wireless Message Display Using I2C LCD Keypad Shield

The function of this sketch is same as the sketch posted on May. 11, 2014, but using I2C LCD Keypad Shield as the output device.

Sketch

/*
SimpleReceiveI2CLCD
This sketch displays text strings received using VirtualWire
Connect the Receiver data pin to Arduino pin 11
Modified by Befun Hung on Nov. 09, 2014 
Use I2C LCD Keypad Shield as the output
*/

#include <VirtualWire.h>
#include <Wire.h>
#include <LiquidCrystal_I2C.h>
// #define BACKLIGHT_PIN 13
LiquidCrystal_I2C lcd(0x20); //Set the LCD I2C address
// LiquidCrystal_I2C lcd(0x38, BACKLIGHT_PIN, POSITIVE);

byte message[VW_MAX_MESSAGE_LEN]; // a buffer to store the incoming messages
byte messageLength = VW_MAX_MESSAGE_LEN; // the size of the message
unsigned long counter = 1;

void setup()
{
  // pinMode(BACKLIGHT_PIN, OUTPUT);
  // digitalWrite(BACKLIGHT_PIN, HIGH);
  // set up the LCD's number of columns and rows: 
  lcd.begin(16, 2); //initialize the lcd
  // Print a message to the LCD.
  lcd.home(); //go home
  lcd.print("Device is ready!");
  // 
  Serial.begin(9600);
  Serial.println("Device is ready");
  // Initialize the IO and ISR
  vw_setup(2000); // Bits per sec
  vw_rx_start(); // Start the receiver
}
void loop()
{
  if (vw_get_message(message, &messageLength)) // Non-blocking
  {
    lcd.clear();
    Serial.print(counter);
    Serial.print(": ");
    // set the cursor to column 0, line 1
    // (note: line 1 is the second row, since counting begins with 0):
    lcd.setCursor(0, 0);
    lcd.print(counter);
    lcd.print(":");
    lcd.setCursor(0,1);
    for (int i = 0; i < messageLength; i++)
    {
      Serial.write(message[i]);
      lcd.print(char(message[i]));
    }
    Serial.println();
    counter++;
  }
}

3x4 Keypad Radio Frequency remote control

  To send digits to radio frequency receiver, a 3x4 keypad and a transmitter is a good combination. To use the keypad, the connection between keypad and pins has to be clarified. For my keypad, the connections are:

Keypad.1: Pin1 + Pin5
Keypad.2: Pin1 + Pin6
Keypad.3: Pin1 + Pin7
Keypad.4: Pin2 + Pin5
Keypad.5: Pin2 + Pin6
Keypad.6: Pin2 + Pin7
Keypad.7: Pin3 + Pin5
Keypad.8: Pin3 + Pin6
Keypad.9: Pin3 + Pin7
Keypad.*: Pin4 + Pin5
Keypad.0: Pin4 + Pin6
Keypad.#: Pin4 + Pin7

I just want to send 3 digits range from 000 to 999 to receiver running the sketch posted on May. 11, 2014. The result is showed on the following photo.

Connections

1. Transmitter.Vcc -> Arduino.5V
2. Transmitter.Gnd -> Arduino.Gnd
3. Transmitter.Data -> Arduino.D12
4. Keypad.Pin1 (ROW0) -> Arduino.D5
5. Keypad.Pin2 (ROW1) -> Arduino.D4
6. Keypad.Pin3 (ROW2) -> Arduino.D3
7. Keypad.Pin4 (ROW3) -> Arduino.D2
8. Keypad.Pin5 (COL0) -> Arduino.D8
9. Keypad.Pin6 (COL1) -> Arduino.D7
10. Keypad.Pin7 (COL2) -> Arduino.D6

Photo

Updated Sketch

// Modified by Befun Hung on Oct. 28, 2014   
// Blink led after sending message to notice user 5 times 
#include <Keypad.h>
#include <VirtualWire.h>

#define maxLength 3
const byte ROWS = 4; // four rows
const byte COLS = 3; // three columns
char keys[ROWS][COLS] = {
  {'1','2','3'},
  {'4','5','6'},
  {'7','8','9'},
  {'*','0','#'}
};
// Connect keypad ROW0, ROW1, ROW2 and ROW3 to these Arduino pins.
byte rowPins[ROWS] = {5, 4, 3, 2};
// Connect keypad COL0, COL1 and COL2 to these Arduino pins.
byte colPins[COLS] = {8, 7, 6};    // connect to the column pinouts of the keypad
char keyins[maxLength+1] = "";
int i=0, j=0, sendTimes=5;
int led=13;

Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );

void setup() {
  Serial.begin(9600);
  // Initialize the IO and ISR
  vw_setup(2000); // Bits per sec
  Serial.println("Ready!");
  pinMode(led, OUTPUT);
}
  
void loop() {
    char key = keypad.getKey();
    if (key) {
      Serial.print(key);
      keyins[i] = key;
      i++;
      if (i == maxLength) {
        for (j=0;j<sendTimes;j++) {
          Serial.println();
          send(keyins);
          digitalWrite(led, HIGH);
          delay(20);
          digitalWrite(led, LOW);
          delay(20);
        }
        i = 0;
      } 
    }
}

void send(char *message)
{
  vw_send((uint8_t *)message, strlen(message));
  vw_wait_tx(); // Wait until the whole message is gone
}

Sketch

#include <Keypad.h>
#include <VirtualWire.h>

#define maxLength 3
const byte ROWS = 4; // four rows
const byte COLS = 3; // three columns
char keys[ROWS][COLS] = {
  {'1','2','3'},
  {'4','5','6'},
  {'7','8','9'},
  {'*','0','#'}
};
// Connect keypad ROW0, ROW1, ROW2 and ROW3 to these Arduino pins.
byte rowPins[ROWS] = {5, 4, 3, 2};
// Connect keypad COL0, COL1 and COL2 to these Arduino pins.
byte colPins[COLS] = {8, 7, 6};    // connect to the column pinouts of the keypad
char keyins[maxLength+1] = "";
int i=0;

Keypad keypad = Keypad( makeKeymap(keys), rowPins, colPins, ROWS, COLS );

void setup() {
  Serial.begin(9600);
  // Initialize the IO and ISR
  vw_setup(2000); // Bits per sec
  Serial.println("Ready!");
}
  
void loop() {
    char key = keypad.getKey();
    if (key) {
      Serial.print(key);
      keyins[i] = key;
      i++;
      if (i == maxLength) {
        Serial.println();
        send(keyins);
        i = 0;
      }
    }
}

void send(char *message)
{
  vw_send((uint8_t *)message, strlen(message));
  vw_wait_tx(); // Wait until the whole message is gone
}

Arduino RF Wireless Message Display

As I am building the RF wireless power socket for home automation, I need a stand along tool to display any wireless received message. During the lab, I use Arduino serial monitor to monitor the message received once a second, error always happens at different time point as following screen shot shows. After disconnecting the Arduino Uno from PC to monitor message received by using LCD keypad shield as a stand along system, the error condition gone.
The RF wireless message display can be used to display the time on the NTP synchronized RTC clock (my projects during Aug 2013), so no additional time adjustment at display side is needed.

Parts Used

1. Arduino Uno R3
2. cheaphousetek LCD Keypad Shield
3. RF Receiver (described in Arduino Cookbook 14.1)

Connection

1. Stack LCD Key Keypad Upon Arduino Uno R3
2. RF Receiver Data Pin - Arduino Uno D11
3. RF Receiver Vcc - Arduino Uno 5V
4. RF Receiver Gnd - Arduino Uno Gnd

Photo

The sketch runs correctly with output to LCD shield for 247,610 times.

Sketch

/*
SimpleReceiveLCD
This sketch displays text strings received using VirtualWire
Connect the Receiver data pin to Arduino pin 11
*/
#include <VirtualWire.h>
// include the library code:
#include <LiquidCrystal.h>
byte message[VW_MAX_MESSAGE_LEN]; // a buffer to store the incoming messages
byte messageLength = VW_MAX_MESSAGE_LEN; // the size of the message
unsigned long counter = 1;
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);
void setup()
{
  // set up the LCD's number of columns and rows: 
  lcd.begin(16, 2);
  // Print a message to the LCD.
  lcd.print("hello, world!");
  lcd.clear();
  Serial.begin(9600);
  Serial.println("Device is ready");
  // Initialize the IO and ISR
  vw_setup(2000); // Bits per sec
  vw_rx_start(); // Start the receiver
}
void loop()
{
  if (vw_get_message(message, &messageLength)) // Non-blocking
  {
    lcd.clear();
    Serial.print(counter);
    Serial.print(": ");
    // set the cursor to column 0, line 1
    // (note: line 1 is the second row, since counting begins with 0):
    lcd.setCursor(0, 0);
    lcd.print(counter);
    lcd.print(":");
    lcd.setCursor(0,1);
    for (int i = 0; i < messageLength; i++)
    {
      Serial.write(message[i]);
      lcd.print(char(message[i]));
    }
    Serial.println();
    counter++;
  }
}