If ASCII codes are only 7 bit, why my laptop keyboard has too many wires in its bus connection ?

crutschow

Joined Mar 14, 2008
34,285
It varies with the keyboard design.
You'd have to find the schematic for the specific keyboard you have.
There are additional wires for power and ground, as well as special functions that aren't in the ASCII code.
 

Alec_t

Joined Sep 17, 2013
14,280
The keys are arranged as a matrix (rows and columns), which is scanned to identify which key is pressed.
Keyboards vary, but mine has 6 rows of 18 keys. Those could be scanned using 6+18 wires plus a ground connection, = 25 wires. Yours may be similar.
 
Top