Smart Machine Smart Decision
SIM800H _Hardware Design_V2.03
41
2016-10-10
4.10.
Keypad Interface
The keypad interface consists of 5 keypad column outputs and 5 keypad row inputs. with total 5*5*2, which is 50
keys.
Module has two connections, which supports 25 keys and anther supports 50 keys.
KBR4
KBR3
KBR2
KBR1
KBR0
KBC0
KBC1
KBC2
KBC3
KBC4
Module
Figure 37: 25 keys reference circuit
Note
:
According to the traditional 5*5 to design buttons, when there is spare KBC or KBR, customer can execute AT command
to define as GPIO for details please see the relevant manuals.
Module supports a new key connection, can support 50 keys, which meets full keyboard demand, the connection
diagram is as following:
KBR4
KBR0
KBC0
KBC4
20K
Module
20K
Figure 38: 50 keys reference circuit
Note
:
Do not change the 20KΩ resistor in the diagram.
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