Checking for Backspace char, ASCII 8

Hello!

I've got a sketch that gets text characters from the serial (USB) port that's connected to a PC running Putty. The user types in commands. A chr(13) (Enter key) indicates the end of the text.

I check for a char 13 to detect the end of the command without any problem, but I can't detect the back space char 8:

if (inChar == 13) {

whatever

}

if (inChar == 8) ...

I added a Serial.println(inChar); to display the ASCII of the char and it displays 12 for the backspace char.

How can I check for the BS char?

Thanks! Sgarciav

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Gough Lui over 5 years ago

It may be the fault of PuTTY - see https://www.ssh.com/ssh/putty/putty-manuals/0.68/Chapter4.html#config-backspace
4.4.1 Changing the action of the Backspace key
Some terminals believe that the Backspace key should send the same thing to the server as Control-H (ASCII code 8). Other terminals believe that the Backspace key should send ASCII code 127 (usually known as Control-?) so that it can be distinguished from Control-H. This option allows you to choose which code PuTTY generates when you press Backspace.
Check your connection options when you set-up in PuTTY:

- Gough
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SGarciaV over 5 years ago in reply to Gough Lui

Argh. I wouldn't have occurred to me to look at Putty. I refactored my code to no avail. I select the Control-H option in Putty and everything is working. Thank you! Sgarciav
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Checking for Backspace char, ASCII 8

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4.4.1 Changing the action of the Backspace key