SBC

Raspberry Pi 1 Model A specs, pinout & datasheets

Single-board computer · Raspberry Pi · Released February 2013

The cut-down $25 version of the first Raspberry Pi: one USB port, no Ethernet and 256 MB of RAM, for projects that needed less power and cost.

Chip / SoC: Broadcom BCM2835
CPU: Arm1176JZF-S (ARMv6), single core
Clock: 700 MHz
RAM: 256 MB
Storage: Full-size SD card
I/O voltage: 3.3 V
Released: February 2013
Status: Retired

Draft entry: these specs were compiled from the linked sources and are waiting for a second check. Spotted a mistake? Use the form at the end of the page.

Specifications

12 specs

Chip / SoC: Broadcom BCM2835^[2]
CPU: Arm1176JZF-S (ARMv6), single core^[3]
Clock: 700 MHz^[7]
RAM: 256 MB^[2]
Storage: Full-size SD card^[2]
GPIO: 26-pin header (P1)^[2]
I/O voltage: 3.3 V^[4]
Input voltage: 5 V via micro-USB^[2]
USB: 1 × USB 2.0^[2]
Video: HDMI and RCA composite; DSI display connector^[2]
Expansion: CSI camera connector^[2]
Launch price: US$25^[7]

Can I still use it?

1 platforms

Raspberry Pi OS: Supported^[8]32-bit image; the 64-bit image needs a 64-bit model such as the Pi 3 or later.

As published by each project, checked weekly. A platform not listed has no published information here, which is not the same as no support.

Datasheets and documents

1 documents

Raspberry Pi hardware documentationGuide

Pinout

26 pins

Raspberry Pi 26-pin GPIO header (P1, revision 2)^[4]

Power
Ground
GPIO
Special
Not connected

Pin table (26 pins)

P1 (26-pin GPIO)
Pin	Label	Kind	Functions
1	3V3	Power
2	5V	Power
3	GPIO2	GPIO	I2C1 SDA
4	5V	Power
5	GPIO3	GPIO	I2C1 SCL
6	GND	Ground
7	GPIO4	GPIO	GPCLK0
8	GPIO14	GPIO	UART TXD
9	GND	Ground
10	GPIO15	GPIO	UART RXD
11	GPIO17	GPIO
12	GPIO18	GPIO	PCM CLK, PWM0
13	GPIO27	GPIO
14	GND	Ground
15	GPIO22	GPIO
16	GPIO23	GPIO
17	3V3	Power
18	GPIO24	GPIO
19	GPIO10	GPIO	SPI0 MOSI
20	GND	Ground
21	GPIO9	GPIO	SPI0 MISO
22	GPIO25	GPIO
23	GPIO11	GPIO	SPI0 SCLK
24	GPIO8	GPIO	SPI0 CE0
25	GND	Ground
26	GPIO7	GPIO	SPI0 CE1

Gotchas

3 known issues

No Ethernet. The Model A has no network port; networking needs a USB adapter on its single USB port, so a powered hub is usually needed for anything more.^[2]
3.3 V only. The GPIO pins are 3.3 V. Do not connect 5 V signals or components to them.^[4]
Little current per pin. Each GPIO pin can supply up to about 16 mA and all pins together about 50 mA; drive motors and other loads through a transistor or driver board.^[5]

What changed

From the specs

Next came the Raspberry Pi 1 Model A+

Spec	Raspberry Pi 1 Model A	Raspberry Pi 1 Model A+
RAM	256 MB	256 MB; later boards 512 MB
Storage	Full-size SD card	microSD card
GPIO	26-pin header (P1)	40-pin header
Video	HDMI and RCA composite; DSI display connector	HDMI; composite on the 3.5 mm AV jack; DSI display connector
Launch price	US$25	US$20

Power and battery

3 facts

Recommended supply: 700 mA^[5]
USB peripheral budget: 500 mA^[5]
Typical bare-board draw: 200 mA^[5]

History and use today

Editorial

History

The Model A followed the Model B a year later as the cheaper, lower-power option: the same BCM2835 with half the RAM, one USB port and no Ethernet chip.^[7]

Still useful for

Its low draw (about 200 mA idle) still makes it usable in battery-powered or solar logging projects, but a Pi Zero does the same job in a smaller board.

Sources

8 sources

Spotted a mistake?

Reviewed by hand

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