5.- Radio Frequency 433 MHZ. ASK. OOK.
-
Modulation Digital ASK (Amplitude-Shift Keying).
-
To transmit a "1" use an Amplitude. To transmit a "0" use another Amplitude. The frequency of Carrier is the same in the two states.
- Modulation Digital OOK ( On-Off Keying).
-
These are two old, classic and cheap modules: FS1000A and JY-JS03.
-
Frequency: 433 MHz. Modulation: ASK. Price: about $ 1.
-
Range: about 10 m indoor, 90 m outdoor.
-
In my example the antenna is a 34 cm wire.
- App.
p9AAi_bluetooth_radiofrecuencia.aia (4.3 KB)
[this application is common for the following modules.]
-
App sends by Bluetooth a message to Arduino with HC-06 BT module.
-
Arduino gets the message and passes it through terminal 12 to the RF emitter.
-
The RF receiver receives the message and passes it to another Arduino through terminal 11.
The message is displayed on the Serial Monitor. -
The first Arduino use a battery as a Power Supply, the second Arduino is connected to a PC.
- In this code, if TimerEnabled is false you can write and send a message.
- If TimerEnabled is true, the timer automatically sends a sequence of numbers (1, 2, 3, 4,...)
- Arduino. Emitter code:
#include <RH_ASK.h>
#include <SPI.h>
char caracterfinal = '\n';
String texto;
RH_ASK rf_driver;
// Conectar DATA al terminal 12 del Arduino.
void setup(){
Serial.begin(9600);
rf_driver.init();
}
void loop() {
if(Serial.available()) {
texto = Serial.readStringUntil(caracterfinal); // from App by Bluetooth
Serial.println(texto);
char *msg = texto.c_str();
rf_driver.send((uint8_t *)msg, strlen(msg)); // FS1000A sends msg
rf_driver.waitPacketSent();
}
}
- Arduino. Receiver code:
#include <RH_ASK.h>
#include <SPI.h>
RH_ASK rf_driver;
// Conectar DATA al terminal 11 del Arduino.
void setup(){
Serial.begin(9600);
rf_driver.init();
}
void loop(){
uint8_t buf[16] = {""}; // Size buffer 16.
uint8_t buflen = sizeof(buf);
if (rf_driver.recv(buf, &buflen)){
Serial.print("Mensaje recibido: ");
Serial.println((char*)buf);
}
}
- Library: RadioHead. [it also works with the VirtualWire library.]