Hytera MD78X - DB26 Accessory Interface

VHF (136MHz
–
174MHz)
Interface Definition
37
Pin 1 Pin 10 Radio Status
High Level Low Level
The mobile radio is connected to an external speaker (including
desktop microphone with earpiece).
High Level High Level
The mobile radio is in USB slave mode, or it is not connected to any
accessory, or it is connected to a palm microphone without keypad.
7.2 DB26 Accessory Interface
DB26 accessory interface, namely the 26-pin further development interface on the rear panel, is mainly
used for accessory connection of mobile radio, or compatibility with other interfaces. Users can further
develop the radio via this interface. The figure and definition of each pin is as follows.
Pin
No.
Name Type
Signal Electrical
Performance
Description
1
Vbus USB
power supply
Power output
Power supply: +5V;
current limiting: 500 mA
Pin 1 and Pin 10 (accessory
identification interface 2)
compose an accessory
identification matrix. This
pin outputs a 5 V voltage
when accessory
identification code is
00|01|10, and outputs low
level when the code is 11.
2 Ground
Power supply
(grounding)
/ /
3
GP5_3
(Chan_Act)
GPIO 5V TTL
GPIO. Programmable via
CPS.