User`s manual

6.9.2 GPIO-2 (General Purpose Input/Output) 40pin connector

The GPIO pins are led out on a separate 40pin connecter. They allow the user to attach additional

hardware, check readings or perform hardware debug. The GPIO-2 connector numbers are printed

at the bottom of the board for your convenience.

GPIO-2 connector

GPIO pin# Signal name Processor pin# GPIO pin# Signal name Processor pin#

1 5V - 2 GND -

3 3.3V - 4 LDO3_2.8V Goes to AXP209

5 TWI0-SCK A15 6 PE0 E23

7 TWI0-SDA B15 8 PE1 E22

9 PI0 A20 10 PE2 D23

11 PI1 B20 12 PE3 D22

13 PI2 A19 14 PE4 C23

15 PI3 B19 16 PE5 C22

17 PI10 C17 18 PE6 B23

19 PI11 D17 20 PE7 B22

21 PC3/NCE1 L22* 22 PE8 A23

23 PC7/NRB1 J22* 24 PE9 A22

25 PC16 M21 26 PE10 B21

27 PC17 F23 28 PE11 A21

29 PC18 F22 30 PI21 E13

31 PC23 G19 32 PI20 E14

33 PC24/NQS F21* 34 PI19 D14

35 GPIO1 - 36 PI18 E15

37 GPIO2 - 38 PI17 E16

39 GPIO3 - 40 PI16 E17

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).

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