Odd Serial behavior with Uno

Question

I'm not understanding what's going on with my Uno. I have a very simple piece of code. no peripherals are connected. Just a bare genuine uno. I program in VisualMicro for Visual Studio.

void setup()
{
    Serial.begin(115200);

    char stringy[9] = { 0x7E, 0x00, 0x05, 0x08, 0x01, 0x44, 0x33, 0x04, 0x7B };

    for (int i = 0; i < 9; i++) {

        Serial.print(stringy[i]);
        //delay(300);
    }

    Serial.println("");
    Serial.print("done");
}

void loop()
{
    while (1) {  }
}

Without a delay of around 250msec or greater in the for loop, I don't get all the characters. In fact, without the delay, the code doesn't even finish executing. I only get the first character '~'. It doesn't seem to matter what my baud rate is.

This code runs fine without a delay on my Nano. What could possibly be the issue?

Answer 1

You are printing the unprintable.

Do you think it should print:

~0581,34{

or

0x7E 0x00 0x05 0x08 0x01 0x44 0x33 0x04 0x7B 

What you will get is

tilde
null
enquiry
backspace
start of heading
comma
three
end of transmission
open brace

I think you can call

Serial.print(stringy[i], HEX);

To see the number you put in come out.