Raspberry Pi Zero WH — Official Reference¶

Future hardware

The Pi Zero WH is planned for Phase 5 (migration from Pico W). This reference is kept for future use. For the current development board, see Pico W Reference.

Source: raspberrypi.com/documentation

Hardware Specifications¶

Spec	Value
SoC	BCM2835
CPU	ARM1176JZF-S, 1GHz single-core
RAM	512MB LPDDR2 SDRAM
Wi-Fi	802.11 b/g/n 2.4GHz
Bluetooth	4.2 + BLE
USB	Micro-USB OTG
Video	Mini HDMI
Camera	CSI connector (flex cable)
Storage	Micro SD
GPIO	2×20 40-pin header (pre-soldered on WH)
Dimensions	65 × 30 × 5mm
Operating temp	0°C to 70°C
Recommended power	5V DC, 2.5A

Complete 40-Pin GPIO Pinout¶

3.3V only

GPIO pins are 3.3V logic. They are NOT 5V tolerant. Applying 5V to any GPIO pin will permanently damage the SoC.

Physical Pin	BCM GPIO	Primary Function	Notes
1	—	3.3V power	~500mA total rail
2	—	5V power	Direct from USB
3	GPIO 2	I²C SDA1	1.8kΩ pull-up onboard
4	—	5V power
5	GPIO 3	I²C SCL1	1.8kΩ pull-up onboard
6	—	GND
7	GPIO 4	GPCLK0	General-purpose clock
8	GPIO 14	UART TXD0	Serial transmit
9	—	GND
10	GPIO 15	UART RXD0	Serial receive
11	GPIO 17	GPIO	e-Paper RST
12	GPIO 18	PWM0 / PCM CLK	Hardware PWM
13	GPIO 27	GPIO
14	—	GND
15	GPIO 22	GPIO
16	GPIO 23	GPIO
17	—	3.3V power	Second 3.3V source
18	GPIO 24	GPIO	e-Paper BUSY
19	GPIO 10	SPI0 MOSI	e-Paper DIN
20	—	GND
21	GPIO 9	SPI0 MISO	Unused by e-paper
22	GPIO 25	GPIO	e-Paper DC
23	GPIO 11	SPI0 SCLK	e-Paper CLK
24	GPIO 8	SPI0 CE0	e-Paper CS
25	—	GND
26	GPIO 7	SPI0 CE1
27	GPIO 0	ID EEPROM SDA	HAT ID — reserved
28	GPIO 1	ID EEPROM SCL	HAT ID — reserved
29	GPIO 5	GPIO	Button UP
30	—	GND
31	GPIO 6	GPIO	Button DOWN
32	GPIO 12	PWM0
33	GPIO 13	PWM1	Button LEFT
34	—	GND
35	GPIO 19	PCM FS / PWM	Button RIGHT
36	GPIO 16	GPIO
37	GPIO 26	GPIO	Button CENTER
38	GPIO 20	PCM DIN
39	—	GND
40	GPIO 21	PCM DOUT

Pins marked bold are used by the Dilder hardware — see Wiring & Pinout for the full assignment table.

GPIO Electrical Limits¶

Parameter	Value
Logic voltage	3.3V max
HIGH input threshold	≥ 1.8V
LOW input threshold	≤ 0.8V
Max current per GPIO pin	16mA
Max total GPIO current	50mA
3.3V rail current	~500mA
Internal pull resistors	~50kΩ (software configurable)

Protocol Pin Assignments¶

SPI (used by the e-ink display)¶

Signal	BCM GPIO	Physical Pin
MOSI	GPIO 10	19
MISO	GPIO 9	21
SCLK	GPIO 11	23
CE0 (CS)	GPIO 8	24
CE1	GPIO 7	26

SPI mode for the Waveshare display: Mode 0 (CPOL=0, CPHA=0), MSB-first.

I²C¶

Signal	BCM GPIO	Physical Pin
SDA1	GPIO 2	3
SCL1	GPIO 3	5

UART¶

Signal	BCM GPIO	Physical Pin
TXD0	GPIO 14	8
RXD0	GPIO 15	10

Hardware PWM¶

Signal	BCM GPIO	Physical Pin
PWM0	GPIO 12	32
PWM1	GPIO 13	33
PWM0 (alt)	GPIO 18	12
PWM1 (alt)	GPIO 19	35

GPIO Numbering — BCM vs Physical¶

Always use BCM numbers in code

The Waveshare library and RPi.GPIO default to BCM numbering — the number after "GPIO" (e.g. GPIO 17 = BCM 17). Physical pin numbers are the 1–40 positions on the header. These are different. Using physical numbering by mistake will connect to the wrong pin.

import RPi.GPIO as GPIO
GPIO.setmode(GPIO.BCM)   # use BCM — always set this
GPIO.setup(17, GPIO.OUT) # GPIO 17 = physical pin 11

Official Links¶

Resource	URL
Pi Zero W product page	raspberrypi.com/products/raspberry-pi-zero-w
Hardware documentation	raspberrypi.com/documentation/computers/raspberry-pi.html
GPIO documentation	raspberrypi.com/documentation/computers/raspberry-pi.html#gpio
Schematics (PDF)	datasheets.raspberrypi.com/rpizero
Interactive pinout	pinout.xyz