const char and Strng

Using Arduino Programming Questions
1

Hi,

I'm trying to send a message over a wireless module,
I need to send a string of text but i'm getting a error:
How do i fix this problem?

sketch_apr28a.ino: In function 'void loop()':
sketch_apr28a:14: error: cannot convert 'String' to 'const char*' in initialization

#include <VirtualWire.h>
void setup()
{
  
    vw_set_ptt_inverted(true);  // Required by the RF module
    vw_setup(2000);            // bps connection speed
    vw_set_tx_pin(3);         // Arduino pin to connect the receiver data pin
}
 
void loop()
{
  String message = "Test";

   const char *msg = message;
   vw_send((uint8_t *)msg, strlen(msg));
   vw_wait_tx();        // We wait to finish sending the message
   delay(200);         // We wait to send the message again                
}
2 
char* message = "Test";
3

How do i solve this?

ZenderWeer.ino: In function 'void loop()':
ZenderWeer:19: error: invalid conversion from 'int' to 'char*'

#include <VirtualWire.h>
#include <dht.h>
#define dht_dpin A0

dht DHT;
void setup()
{
    
  
    vw_set_ptt_inverted(true);  // Required by the RF module
    vw_setup(2000);            // bps connection speed
    vw_set_tx_pin(3);         // Arduino pin to connect the receiver data pin
}
 
void loop()
{
   DHT.read11(dht_dpin);
int temp = (DHT.humidity);
char* temperature = temp;

  const char *msg = temperature;
   vw_send((uint8_t *)msg, strlen(msg));
   vw_wait_tx();        // We wait to finish sending the message
   delay(200);         // We wait to send the message again                
}
4

Don't have two variables in the same scope with the same name

5

Sorry, didn't see i updated the message.

ZenderWeer.ino: In function 'void loop()':
ZenderWeer:19: error: invalid conversion from 'int' to 'char*'
6

Use sprintf or itoa

7

Yes.... But how? can you give me a fix?

8

Yes.... But how? can you give me a fix?

You got a hint. Now, pretend that you really want to learn, and google those two functions.