Problems using multiple modifiers

[FriedrichFroebel]

I am currently trying to get my PCSensor foot switch to work using multiple modifier keys at once with my German keyboard layout on Ubuntu 18.04.

Basically I need Alt Ctrl + 7 which inserts { using the regular keyboard. Trying to use either

• ./footswitch -S 'e9 e3' -s 7 (leading to <XF86Eject><Super_L>7 with -r) or
• ./footswitch -m alt -m ctrl -k 7 (leading to ctrl+alt+7)

does not seem to work. (These codes are from xmodmap -pk and xev -event keyboard. There are other problems using the ones from the linked USB HID usage table.) In the first case, it will just print 7 and the second case does not seem to produce any output at all.

Trying to use ß as a key (to get a backslash) does not work as well as this character cannot be encoded: Cannot encode key 'ß'.

Is there anything I can do about this?

(By the way: Using the "official" software on Windows the ssharp character does not work, too, as the software inserts ] instead. Configuring the foot switch on Windows and using the configured keys on Ubuntu does not work as well as the wrong output gets produced.)

[rgerganov]

I am currently trying to get my PCSensor foot switch to work using multiple modifier keys at once with my German keyboard layout on Ubuntu 18.04.

Basically I need Alt Ctrl + 7 which inserts { using the regular keyboard. Trying to use either

I guess you have some additional input handler which "translates" Alt+Ctrl+7 to {. I get no output when I press this on my keyboard. Why not simply using footswitch -k '{'?

[FriedrichFroebel]

German keyboard layouts have a dedicated Alt Gr key and { is the third option of the key 7. According to xev this key seems to be mapped to keycode 108 (keysym 0xfe03, ISO_Level3_Shift) with my setup.

footswitch -k '{' does not produce any output, xev says this writes keycode 248 (keysym 0x0, NoSymbol).