Arduino通过蓝牙将垃圾值发送到Android App（App Inventor 2）

Question

I just used an arduino code to send text data to an android application which I made in app inventor. I used Bluetooth module HC-05 for connectivity.It almost works but instead of sending few characters, it sends junk data. Here's the arduino code:

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

}
void loop()
{
  Serial.println("h");
  delay(500);
  Serial.println("s");
  delay(500);
  Serial.println("o");
  delay(500);
}

And here's the App blocks and Design:

And here's the screenshot when I ran the app:

I click "Show" and I get these random junk data. And the next time I click show, I don't get any data at all. Can anybody explain how to solve this ?

Answer 1

For Junk values, Try to change the baud rate!

I think you are sending a data from BT device to android device only one time. try running the code continuously in arduino device.

while(1){ loop(); }

Answer 2

• Check if you connected BT module to USART0 (RX0, TX0) port
• try change baud rate, usually HC05 has 9600, but it may have also 19200 and sometimes 115200.
• note, that HC05 has 3.3V, and almost all Arduino boards are 5V. So you need to use level shifters. Else specify what board and module you use