OLIMEX© 2018
A20-OLinuXino-MICRO user's manual
MIC_IN connector
Pin #
Signal name
Processor pin
2
MICIN
AC20
3
MICIN
AC20
5
GND
-
The socket can interface standard 3.5 mm phone connector (also known stereo plug or audio plug).
Headphones connector
Pin #
Signal name
Processor pin
2
HPOUTL
Y19
3
HPOUTR
W19
5
HPCOM (GND)
AA19, AA20
The connector can interface standard 3.5 mm phone connector (also known stereo plug or audio
plug).
The default audio output is set to the HDMI connector (for displays and monitors with built-in
audio speakers). If you wish to use audio out you need to first disconnect the HDMI, boot the board,
connect the audio out device (speakers) and finally connect the HDMI.
6.5 USB_OTG connector
The part of the schematic related to the USB_OTG is shown below:
The USB_OTG features Low Loss Power Distribution Switch SY6280 which protects the board in
case the devices you have plugged to the USB_OTG attempt to draw more current than 523mA
combined. The maximum current available on the 5V USB_OTG is exactly 523mA.
The SY6280 responsible for the USB_OTG is enabled by USB0-DRV (processor pin C12), thus the
USB_OTG is also controlled by the same signal.
There are two parts of a successful OTG device/host mode switch and usage – hardware part and
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