GPIO Modes

R64.GPIO supports three GPIO modes: ROCK, BOARD, and BCM.

• ROCK is the default mode, which uses standard Rock64 GPIO numbers.
  
• BOARD allows you to use pin numbers when working with GPIOs instead of GPIO numbers.
  
• BCM attempts to emulate the layout of the Raspberry Pi's 40-pin header.
  
  • BCM 4, 5, 6, 17, and 27 are mapped to the Pi P5+ header due to compatibility issues.
  • BCM 12, 13, 16, 19, 20, 21, and 26 are not usable if a MicroSD card is inserted.
  • BCM is only able to access 28 (out of 33 total) GPIOs.

The following table compares all available layouts against the physical pin-outs of the Pi-2 and Pi P5+ buses.

Pin# (Physical)	Pin# (BOARD)	GPIO# (ROCK)	GPIO# (BCM)	Confirmed Working?
Pi-2: 3	3	89	2	YES
Pi-2: 5	5	88	3	YES
Pi-2: 7	7	60		YES (May cause crashes)
Pi-2: 8	8	64	14
Pi-2: 10	10	65	15
Pi-2: 12	12	67	18	YES (Input Only)
Pi-2: 15	15	100	22	YES
Pi-2: 16	16	101	23	YES
Pi-2: 18	18	102	24	YES
Pi-2: 19	19	97	10
Pi-2: 21	21	98	9
Pi-2: 22	22	103	25	YES
Pi-2: 23	23	96	11
Pi-2: 24	24	104	8
Pi-2: 26	26	76	7
Pi-2: 27	27	68	0
Pi-2: 28	28	69	1
Pi-2: 32	32	38	12	YES (No MicroSD)
Pi-2: 33	33	32	13	YES (No MicroSD)
Pi-2: 35	35	33	19	YES (No MicroSD)
Pi-2: 36	36	37	16	YES (No MicroSD)
Pi-2: 37	37	34	26	YES (No MicroSD)
Pi-2: 38	38	36	20	YES (No MicroSD)
Pi-2: 40	40	35	21	YES (No MicroSD)
Pi P5+: 3	43	81	4	YES
Pi P5+: 4	44	82	27	YES
Pi P5+: 5	45	87	5	YES
Pi P5+: 6	46	83	6	YES
Pi P5+: 9	49	80	17	YES
Pi P5+: 10	50	79		YES
Pi P5+: 11	51	85		YES
Pi P5+: 12	52	84		YES
Pi P5+: 13	53	27
Pi P5+: 14	54	86		YES
Pi P5+: 21	61	89	2	YES (Duplicate)
Pi P5+: 22	62	88	3	YES (Duplicate)