Help using RH_ASK with OLED display

Using Arduino Displays
1

I'm trying to build an indoor/outdoor thermometer using 433 MHz rf modules, OLED display, and DHT22. As a beginner, I'm basically just combining code from the examples in the libraries. I can make all the three parts work independently, but when I combine the RH_ASK code with the OLED code, the message gets extra gibberish tacked on to the message, and the Void loop only iterates once. I'm guessing there is some sort of conflict between the libraries, or else I'm doing something stupid. I'm using two Uno R3 clones. Here is the code:
XMTR:



#include <RH_ASK.h>
#include <SPI.h> // Not actually used but needed to compile

RH_ASK driver;

void setup()
{
    Serial.begin(9600);    // Debugging only
    if (!driver.init())
         Serial.println("init failed");
}

void loop()
{
    const char *msg = "RF Msg";
    driver.send((uint8_t *)msg, strlen(msg));
    driver.waitPacketSent();
    delay(1000);
    Serial.println("Xmit");
}

Rcvr:



#include <RH_ASK.h>
#include <SPI.h> // Not actualy used but needed to compile
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 32

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

RH_ASK driver;

     String testmsg = "test";
     int j = 1;

void setup()
{
 
    Serial.begin(9600);  // Debugging only 
    
    if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C))
          Serial.println("SSD1306 Allocation Failed");
    
    if (!driver.init())
          Serial.println("init failed");
          
    display.clearDisplay();
    display.setTextSize(2);
    display.setTextColor(WHITE);
    display.setCursor(0,18); // (X,Y)
    display.print("Setup");
    display.display();
    Serial.println("Setup");
    delay(1000);
    display.clearDisplay();
    display.display();
   
}

void loop()
{
/*    display.clearDisplay();
    display.setTextSize(2);
    display.setTextColor(WHITE);
    display.setCursor(0,18);
    display.print("Loop");
*/ 
    uint8_t buf[6];
    uint8_t buflen = sizeof(buf);
    if (driver.recv(buf, &buflen)) // Non-blocking
    {
      int i;
      // Message with a good checksum received, dump it.
      Serial.print("Message: ");
      Serial.println((char*)buf);
      
      display.clearDisplay();
      display.setCursor(0, 0);
      display.print(testmsg);
      display.setCursor(64,0);
      display.print(j);
      display.setCursor(0, 18);
      display.print((char*)buf);
      display.display();  
      j++;  
      }       
}

Thanks

2

For several reasons, don't use Strings, especially on the Uno R3.

The RadioHead library requires you to use C-strings (zero terminated character arrays). Make sure that the zero byte is transmitted, otherwise the string will not be properly terminated at the receiver.

Replace this:

    const char *msg = "RF Msg";
    driver.send((uint8_t *)msg, strlen(msg));

with this:

    const char msg[] = "RF Msg";
    driver.send((uint8_t *)msg, strlen(msg)+1);  //include zero terminator
3

Thanks, but no change in behavior.

4

Must be that you are not doing it right.
Have a read of this:-
http://www.thebox.myzen.co.uk/Tutorial/Merging_Code.html

5

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