Repeater GPIO Connections

RPi 4 GPIO pin out

• Note the RPi4 (only) can be powered with 5.2 v directly on Pins 2 and 4. Ground is Pins 6, 9, 14, 20, 25, 30, 34 and 39.

GPIO Connections for the ATV Repeater

Here is the initial list of GPIO connections.

Pin No	BCM No	Wiring Pi	RPi Pri	RPi Alt0	Primary Use	Secondary Use	Notes
1	-	-	3.3v	-	-	-	Future Clock module?
2	-	-	5v	-	-	-	-
3	2	8	GPIO 2	SDA1	-	-	Future Clock module?
4	-	-	5v	-	-	-	-
5	3	9	GPIO 3	SCL1	-	-	Future Clock module?
6	-	-	0v	-	-	-	-
7	4	7	GPIO 4	GPCLK0	-	-	Future Clock module?
8	14	15	GPIO 14	TXD0	-	-	Future RS-232?
9	-	-	0v	-	-	-	Future Clock module?
10	15	16	GPIO 15	RXD0	-	-	Future RS-232?
11	17	0	GPIO 17	FL1	-	-	IR Sensor Input?
12	18	1	GPIO 18	-	IR Sender Output	-	To control HDMI Switch
13	27	2	GPIO 27	SD0_DAT3	Button - Down	-	Active low
14	-	-	0v	-	-	-	-
15	22	3	GPIO 22	SD0_CLK	Button - Left	-	Active low
16	23	4	GPIO 23	SD0_CMD	Button - Right	-	Active low
17	-	-	3.3v	-	-	-	-
18	24	5	GPIO 24	SD0_DAT0	Button - Select	-	Active low
19	10	12	GPIO 10	SPI0_MOSI	-	-	Future Pri TS
20	-	-	0v	-	-	-	-
21	9	13	GPIO 9	SPI0_MISO	-	-	Future Pri TS
22	25	6	GPIO 25	SD0_DAT1	Button - Back	-	Active low
23	11	14	GPIO 11	SPI0_SCLK	-	-	Future Pri TS
24	8	10	GPIO 8	SPI0_CE0_N	-	-	Future Pri TS
25	-	-	0v	-	-	-	-
26	7	11	GPIO 7	SPI0_CE1_N	Hardware Shutdown	-	Active low if enabled
27	0	30	ID_SD	SDA0	Reserved	-	Not Available
28	1	31	ID_SC	SCL0	Reserved	-	Not Available
29	5	21	GPIO 5	GPCLK0	Button - Menu	-	Active low
30	-	-	0v	-	-	-	-
31	6	22	GPIO 6	GPCLK2	Button - Mute	-	Active Low
32	12	26	GPIO 12	PWM0	Band LSB D0	-	-
33	13	23	GPIO 13	PWM1	Band NSB D1	-	-
34	-	-	0v	-	-	-	-
35	19	24	GPIO 19	SPI6_MESO	-	-	Future 2nd TS
36	16	27	GPIO 16	FL0	Button - Power	-	Active low
37	26	25	GPIO 26	SD0_DAT2	Button - OSD Info	-	Active low
38	20	28	GPIO 20	SPI6_MOSI	-	-	Future 2nd TS
39	-	-	0v	-	-	-	-
40	21	29	GPIO 21	SPI6_SCLK	-	-	Future 2nd TS

The clock module that may be used (not tested yet) on pins 1, 3, 5, 7 and 9 is this https://thepihut.com/blogs/raspberry-pi-tutorials/17209332-adding-a-real-time-clock-to-your-raspberry-pi. This would allow the repeater to keep track of time without an internet connection and reset correctly after power outages.

Note that the GPIO pin names are markedly different from the RPi 3B. Each pin on the RPi4 GPIO can be referred to in many ways: its physical pin number, the Broadcom I/O number, the Wiring Pi number or the primary or alternate names. Source for GPIO designations was the Raspberry Pi 4 Model B datasheet.