Problems with HC-12

Other Hardware Sensors
1

Hello, I have been using two HC-12s with Arduino Unos with RX and TX connected to pin 0 and 1 on both Arduinos and GND and VCC connected to 5V and GND on the arduino. However, I cant get them to communicate after trying multiple methods.

#include <SoftwareSerial.h>

SoftwareSerial HC12(1, 0); // HC-12 TX Pin, HC-12 RX Pin

void setup() {
  Serial.begin(9600);             // Serial port to computer
  HC12.begin(9600);               // Serial port to HC12

}

void loop() {
  while (HC12.available()) {        // If HC-12 has data
    Serial.write(HC12.read());      // Send the data to Serial monitor
  }
  while (Serial.available()) {      // If Serial monitor has data
    HC12.write(Serial.read());      // Send that data to HC-12
  }
}

I have been using the same code on both Arduinos with the sending Arduino I get a blinking TX light whenever I send a message in the serial monitor but the receiver doesn't get anything. To see if it was just a code error I also used the code from this github GitHub - DIYTechBros/HC-12 and still no luck.

To ensure it wasn't a hardware error I used a second pair of HC12s and still nothing. Any help is appreciated!

2

1. Try the following connections (Fg-1) using NANO/UNO; where, DPin-1, 0 are not used as they are engaged with PC/Serial Monitor/IDE.

hc12-3q
hc12-3q702×270 17.7 KB

Figure-1:

2. Upload the following sketches on both UNOs:

#include <SoftwareSerial.h>

SoftwareSerial HC12(10, 11); // SRX = 10, STX = 11

void setup() 
{
  Serial.begin(9600);             // Serial port to computer
  HC12.begin(9600);               // Serial port to HC12
}

void loop() 
{
  while (HC12.available()) 
  {        
    Serial.print(HC12.read());     
  }
  while (Serial.available()) 
  {      
    HC12.print(Serial.read());      
  }
}

3. Enter Forum in the InputBox of SM1. Check that Forum has apperaed on SM2.
4. Enter Arduino in the InputBox of SM2. Check that Arduino has apperaed on SM1.

3

Along with what others have suggested above, kindly check if the transmitter and receiver have been paired properly. You can get help from here: https://www.allaboutcircuits.com/projects/understanding-and-implementing-the-hc-12-wireless-transceiver-module/

4

Don't use pins 0 and 1 with SoftwareSerial because they are used by the hardware serial interface. Use any other 2 pins except those

5

okay So I have done this and now I am transmitting but say I put "send" in the serial monitor of one the other just receives a string of numbers "4949534948494949484948484948" which is definitely an improvement but any idea why that's the case?

6

49 49 53 49 48 49 49 49 48 49 48 48 49 48
Looks suspiciously like the ASCII codes for the characters 11510111010010

7

yea I tried putting it into like an ACII converter to see if maybe I was getting the data in that form but I don't think it would make any sense to receive 11510111010010 when sending SEND

8

I should also add that I tried changing the setting of the module while connecting the SET pin to GND but even when I type just AT I receive a random string 69828279821310

9

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