Kenwood 144MHz FM TRANSCEIVER K2E Service Manual page 12

TH-K2AT/K2E/K2ET
Key and Encoder Input Circuit
The POWER key is assigned to the interrupt port (pin 95) of
the MPU.
The PTT key is assigned to the dedicated port (pins 13, 14)
of the MPU.
16 key (K, K2, M, M2 and E3 types)
KIN0
1
4
7
∗
4 key (E type)
KIN0
F
12
CIRCUIT DESCRIPTION
KIN1 KIN2 KIN3 KIN4 KOUT0 KOUT1 KOUT2 KOUT3 PWRSW
2 3 F MENU
5 6 VFO LAMP
8 9 MR MONI
0 # CALL SET
KIN1 KIN2 KIN3 KIN4 KOUT0 KOUT1 KOUT2 KOUT3
VFO MR CALL MENU
LAMP
MONI
SET
Fig. 14 Key and Encoder input circuit
Other keys composes a matrix and key presses are detected
by scanning them by software.
The encoder reads data using the interrupt port (pins 35
and 36) of the MPU.
IC8
MPU
PTTI
95 14
POWER S7
SW
IC8
MPU
PWRSW PTTI
95 14
POWER S7
SW
PTTE ENCB ENCA
13 36 35
ROTARY
ENCODER
J3
PTTE ENCB ENCA
13 36 35
ROTARY
ENCODER
J3