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
}