Page
49
of
54
15
Appendix C: EHS and DHSG API
15.1
EHS Interface
15.1.1
EHS
The EHS connector is compatible with the EA40 standard but is designed so that it may support other
standards in future. The pins are as follow:
Pin no.
Direction Description
1
In/out
Bidirectional IO/SPI DI. Used for SDO in EA40.
Connected to pin 8 in DHSG connector.
2
In
Input IO/SPI CLK. Used for SCLK in EA40.
3
In
Input IO/SPI CS. Used for CS in EA40.
4
Out
Output IO/SPI DO. Used for SDI in EA40.
Connected to pin 1 in DHSG connector.
5
PWR
Power input
6
GND
Ground
15.1.2
Phone
Input for audio signal. The pins can be configured using the slider on the button of the base. The table
below shows that in detail.
Pin no.
Slider position
A
B
C
D
E
F
1
SPK+
SPK-
SPK-
MIC-
SPK-
MIC-
2
MIC-
MIC+
MIC-
SPK-
SPK+
SPK+
3
MIC+
MIC-
MIC+
SPK+
MIC-
SPK-
4
SPK-
SPK+
SPK+
MIC+
MIC+
MIC+
15.1.3
DHSG
The DHSG connector follows the pinout described in the official DHSG standard [DHSG_SPEC]. Other pin
configurations have been seen and to support these, a special cable is needed. The pins are as follow:
Pin no.
Direction
DESCRIPTION
1
Out
Output IO/SPI DO. Used for Data RX in DHSG.
Connected to pin 4 in EHS connector.
2
GND
Ground
3
AUDIO
The audio signals can be configured using the slider as shown in table below.
4
AUDIO
The audio signals can be configured using the slider as shown in table below.
5
AUDIO
The audio signals can be configured using the slider as shown in table below.
6
AUDIO
The audio signals can be configured using the slider as shown in table below.
