Dang it strings!

Projects Programming
1

exit status 1

Compilation error: invalid conversion from 'const char*' to 'unsigned int' [-fpermissive]

uint16_t color;
color=(str.remove("C")).toInt());
2
3

Please post a full sketch showing the data type of the str variable

Is it a String or a string, for example ?
What do you see if you split the single statement and print the result of individual functions ?

4 
//This example code is in the Public Domain (or CC0 licensed, at your option.)
//By Evandro Copercini - 2018
//
//This example creates a bridge between Serial and Classical Bluetooth (SPP)
//and also demonstrate that SerialBT have the same functionalities of a normal Serial

#include <TFT_eSPI.h> // Hardware-specific library for ESP8266

// Invoke TFT library
TFT_eSPI tft = TFT_eSPI();
#include "BluetoothSerial.h"

//#define USE_PIN // Uncomment this to use PIN during pairing. The pin is specified on the line below
const char *pin = "1234"; // Change this to more secure PIN.

String device_name = "RemoteControlX";

#if !defined(CONFIG_BT_ENABLED) || !defined(CONFIG_BLUEDROID_ENABLED)
#error Bluetooth is not enabled! Please run `make menuconfig` to and enable it
#endif

#if !defined(CONFIG_BT_SPP_ENABLED)
#error Serial Bluetooth not available or not enabled. It is only available for the ESP32 chip.
#endif

BluetoothSerial SerialBT;

void setup() {
  Serial.begin(115200);
  SerialBT.begin(device_name); //Bluetooth device name
  Serial.printf("The device with name \"%s\" is started.\nNow you can pair it with Bluetooth!\n", device_name.c_str());
  //Serial.printf("The device with name \"%s\" and MAC address %s is started.\nNow you can pair it with Bluetooth!\n", device_name.c_str(), SerialBT.getMacString()); // Use this after the MAC method is implemented
  #ifdef USE_PIN
    SerialBT.setPin(pin);
    Serial.println("Using PIN");
  #endif
  
  tft.begin();
  tft.setRotation(2);  // 0 & 2 Portrait. 1 & 3 landscape
  tft.fillScreen(TFT_BLACK);
  tft.textcolor=TFT_WHITE;
}
uint16_t color;
uint16_t xval;
uint16_t yval;
void loop() {
  if (Serial.available()) {
    SerialBT.write(Serial.read());
  }
  if (SerialBT.available()) {
  String str = SerialBT.readString();
  if(str.startsWith("C"))
{
color=(str.remove("C")).toInt());
else
        if(str.startsWith("X"))
    {
    xval=(str.remove("X")).toInt();
    else
             if(str.startsWith("Y"))
       { 
        yval=(str.remove("Y")).toInt();
        else
                         if(str.startsWith("P"))
            { 
              tft.drawPixel(xval,yval,color)
               else
                  tft.print(str);
           }
        }
    }
}


  }
  delay(20);
}
5

do not look to that description on the top, I edited the bt serial example to TFT

6

It looks like you may have misunderstood what the remove() function does

Example Code

String greeting = "hello";
greeting.remove(2, 2);  // greeting now contains "heo"
7

That’s the doc for the remove() function

It does not accept a character string literal (const char *) as a parameter

Maybe you wanted to use replace()?

8

...or, as here, a string

9

Indeed i should have written a const char * / string literal

10

color=(str.replace("C","")).toInt());

im getting invalid use of void ???

11

I guess you did not read the doc fully… the function does not return anything.

Returns

Nothing

So you first remove the string, then you call toInt() on the now cleaned up string to get the int

(Please learn to use code tags when pasting code)

str.replace("C","")); // get rid of C
color = str.toInt(); // transform into a long (signed)

What does the String look like? If C is alsays in front as first character you could also just skip it and use other functions to get the conversion going

12

string is coming from BTSERIAL. But theres a if(working with no error) that checks if it starts with

13

Plannned like C65535

14

I think after 50 plus topics and 300 plus posts, it's not unreasonable to expect you to post actual code and actual error messages.

Who knows? You may actually learn something.

15

consider

const char *inp = "C65535";

void setup (void)
{
    Serial.begin (9600);

    char c;
    unsigned  val;

    sscanf (inp, "%c%d", &c, &val);
    Serial.println (val);
}

void loop (void)
{
}
16

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