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OLIMEX© 2015
6.11 GPIO ports
There are three GPIO ports which are used generally to access unused by the board's peripherals
pins. However, there are exceptions – some of the pins might be used to easily peripherals or their
levels.
Most of the pins are already defined in default operating system images. Some of them can be used
as GPIOs, I2C or SPI without much of a problem. Information on the software usage of GPIO ports
might be found in chapters "2.8 GPIO under Debian" and "2.9 I2C and SPI under Debian".
6.11.1 GPIO-1 (General Purpose Input/Output) 40pin connector**
The GPIO-1 plastic connector has 14 pins. The signal layout is described below:
Pin # Signal name
1 +5V
3 +3.3V
5 PG0
7 PG1
9 PG2
11 PG3
13 PG4
15 PG5
17 PG6
19 PG7
21 PG8
23 PG9
25 PG10
27 PG11
29 VGA_HSYNC
31 VGA_VSYNC
33 VGA-G
35 VGA-B
37 VGA-R
39 LRADC1
*Signals marked with * are multiplexed with either a peripheral device or another connector. Ensure that the multiplexing is handled
properly on software and/or hardware level (else there would probably occur wrong levels, loss of data, etc).
**It was erroneously named GPIO-4 in the first release of the board.
***All Android buttons are connected to an ADC (LRADC) that uses a divider to determine which button is pressed.
The yellow part of the table shows all the signals shared with the 6-pin VGA connector.
GPIO-1 connector
Processor pin
-
-
F20
E21
E20
D21
D20
C21
E19
C20
D19
C19
D18
C18
AB9*
AC9*
AC16*
AB16*
AC17*
AB22*
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A20-OLinuXino-MICRO user's manual
Pin # Signal name
2 GND
4 GND
6 VOL+_BUT
8 VOL-_BUT
10 MENU_BUT
12 SEARCH_BUT
14 HOME_BUT
16 ESC_BUT
18 ENTER_BUT
20 TVOUT3
22 TVIN0
24 TVIN1
26 TVIN2
28 TVIN3
30 LINEINR
32 LINEINL
34 FMINR
36 FMINL
38 MIC1OUTP
40 MIC1OUTN
Processor pin
-
-
AB23***
AB23***
AB23***
AB23***
AB23***
AB23***
AB23***
AB17
AC18
AB18
AA17
Y17
AB21
AB20
Y21
Y20
AC22
AC23
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