Raspberry Pi Pico W is a microcontroller board based on the Raspberry Pi RP2040 microcontroller chip.
Figure 1. The
Raspberry Pi Pico W
Rev3 board.
Raspberry Pi Pico W has been designed to be a low cost yet flexible development platform for RP2040, with a 2.4GHz
wireless interface and the following key features:
•
RP2040 microcontroller with 2MB of flash memory
•
On-board single-band 2.4GHz wireless interfaces (802.11n, Bluetooth 5.2)
◦
Support for Bluetooth LE Central and Peripheral roles
◦
Support for Bluetooth Classic
•
Micro USB B port for power and data (and for reprogramming the flash)
•
40-pin 21mm
×
51mm 'DIP' style 1mm thick PCB with 0.1" through-hole pins also with edge castellations
◦
Exposes 26 multi-function 3.3V general purpose I/O (GPIO)
◦
23 GPIO are digital-only, with three also being ADC capable
◦
Can be surface-mounted as a module
•
3-pin Arm serial wire debug (SWD) port
•
Simple yet highly flexible power supply architecture
◦
Various options for easily powering the unit from micro USB, external supplies or batteries
•
High quality, low cost, high availability
•
Comprehensive SDK, software examples and documentation
For full details of the RP2040 microcontroller please see the
RP2040 Datasheet
book. Key features include:
•
Dual-core cortex M0+ at up to 133MHz
◦
On-chip PLL allows variable core frequency
•
264kB multi-bank high performance SRAM
•
External Quad-SPI flash with eXecute In Place (XIP) and 16kB on-chip cache
•
High performance full-crossbar bus fabric
•
On-board USB1.1 (device or host)
•
30 multi-function general purpose I/O (four can be used for ADC)
◦
1.8-3.3V I/O voltage
•
12-bit 500ksps analogue to digital converter (ADC)
•
Various digital peripherals
◦
2
×
UART, 2
×
I2C, 2
×
SPI, 16
×
PWM channels
◦
1
×
timer with 4 alarms, 1
×
real time clock
•
2
×
programmable I/O (PIO) blocks, 8 state machines in total
◦
Flexible, user-programmable high-speed I/O
◦
Can emulate interfaces such as SD card and VGA
NOTE
Raspberry Pi Pico W I/O voltage is fixed at 3.3V
Raspberry Pi Pico W provides a minimal yet flexible external circuitry to support the RP2040 chip: flash memory
(Winbond W25Q16JV), a crystal, power supplies and decoupling, and USB connector. The majority of the RP2040
microcontroller pins are brought to the user I/O pins on the left and right edge of the board. Four RP2040 I/O are used
for internal functions: driving an LED, on-board switch mode power supply (SMPS) power control, and sensing the
system voltages.
Pico W has an on-board 2.4GHz wireless interface using an Infineon CYW43439. The antenna is an onboard antenna
licensed from ABRACON (formerly ProAnt). The wireless interface is connected via SPI to the RP2040.
Pico W has been designed to use either soldered 0.1-inch pin-headers (it is one 0.1-inch pitch wider than a standard 40-
pin DIP package), or to be positioned as a surface-mountable 'module', as the user I/O pins are also castellated. There
are SMT pads underneath the USB connector and BOOTSEL button, which allow these signals to be accessed if used as
a reflow-soldered SMT module.
1.1. Raspberry Pi Pico W design files
The source design files, including the schematic and PCB layout, are made available openly except for the antenna. The
Niche™ antenna is an Abracon/Proant patented antenna technology. Please contact
niche@abracon.com
for
information on licensing.
Schematic
The schematic is reproduced in
Appendix B
. The schematic is also distributed alongside the
layout files
.
Layout
The CAD files, including PCB layout, can be found
here
. Note that Pico W was designed in
Cadence Allegro PCB Editor, and opening in other PCB CAD packages will require an import script
or plugin
2.1. Pico W pinout
The Pico W pinout has been designed to directly bring out as much of the RP2040 GPIO and internal circuitry function
as possible, while also providing a suitable number of ground pins to reduce electro-magnetic interference (EMI) and
signal crosstalk. RP2040 is built on a modern 40nm silicon process, so its digital I/O edge rates are very fast.
