Try it
Characters (· = space, ↵ = newline)
Hex bytes
Understand the result
What's going on
A computer never stores the letter “A” - it stores the number 65. ASCII is just an agreed-upon table that maps every character you can type to a number, and hex is the compact way engineers usually write that number down.
The formula
hex = ASCII_code(char).toString(16)
Repeated for every character in the string, left to right.
Show the derivation, mnemonic, and worked example
Build it up
Take a string, and look up each character’s position in the ASCII table one at a time. That position is a plain decimal number between 0 and 255, which converts to exactly two hex digits. String those hex pairs together, usually with a space between characters, and you’ve got the raw bytes a program or a serial monitor would actually see.
Worked example
Worked example
Text: "Hi"
'H' = 72 decimal = 48 hex
'i' = 105 decimal = 69 hex
Result: 48 69
