Raspberry Pi Pico W
The Raspberry Pi Pico is a general purpose board supplied by the Raspberry Pi Foundation. The W variant adds built in WiFi communications.
Features
RP2040 microcontroller chip
Dual-core ARM Cortex M0+ processor, flexible clock running up to 133 MHz
264kB of SRAM, and 2MB of on-board Flash memory
Castellated module allows soldering direct to carrier boards
USB 1.1 Host and Device support
Low-power sleep and dormant modes
Drag & drop programming using mass storage over USB
26 multi-function GPIO pins
2× SPI, 2× I2C, 2× UART, 3× 12-bit ADC, 16× controllable PWM channels
Accurate clock and timer on-chip
Temperature sensor
Accelerated floating point libraries on-chip
8 × Programmable IO (PIO) state machines for custom peripheral support
Built in WiFi radio (Infineon CYW43439)
Serial Console
By default a serial console appears on pins 1 (TX GPIO0) and pin 2 (RX GPIO1). This console runs a 115200-8N1.
The board can be configured to use the USB connection as the serial console.
Wireless Communication
The on board Infineon CYW43439 supports 2.4 GHz WiFi 4 communications (802.11n), WPS3 and SoftAP with up to four clients.
Pin Mapping
Pin |
Signal |
Notes |
|---|---|---|
1 |
GPIO0 |
Default TX for UART0 serial console |
2 |
GPIO1 |
Default RX for UART1 serial console |
3 |
Ground |
|
4 |
GPIO2 |
|
5 |
GPIO3 |
|
6 |
GPIO4 |
|
7 |
GPIO5 |
|
8 |
Ground |
|
9 |
GPIO6 |
|
10 |
GPIO7 |
|
11 |
GPIO8 |
|
12 |
GPIO9 |
|
13 |
Ground |
|
14 |
GPIO10 |
|
15 |
GPIO11 |
|
16 |
GPIO12 |
|
17 |
GPIO13 |
|
18 |
Ground |
|
19 |
GPIO14 |
|
20 |
GPIO15 |
|
21 |
GPIO16 |
|
22 |
GPIO17 |
|
23 |
Ground |
|
24 |
GPIO18 |
|
25 |
GPIO19 |
|
26 |
GPIO20 |
|
27 |
GPIO21 |
|
28 |
Ground |
|
29 |
GPIO22 |
|
30 |
Run |
|
31 |
GPIO26 |
ADC0 |
32 |
GPIO27 |
ADC1 |
33 |
AGND |
Analog Ground |
34 |
GPIO28 |
ADC2 |
35 |
ADC_VREF |
|
36 |
3V3 |
Power output to peripherals |
37 |
3V3_EN |
Pull to ground to turn off. |
38 |
Ground |
|
39 |
VSYS |
+5V Supply to board |
40 |
VBUS |
Connected to USB +5V |
Other RP2040 Pins
GPIO23 Output - WiFi controller enable. GPIO24 I/O - WiFi controller data line. GPIO25 Output - WiFi controller chip select line. GPIO29 Output - WiFi controller clock line. ADC3 Input - Analog voltage equal to one third of VSys voltage.
Note: ADC3 and GPIO29 share the same pin on the RP2040. If the GPIO25 line is held high (Wifi controller NOT selected) then a voltage equal to one third of the VSys voltage with appear on this line and can be read with ADC3. When the WiFi chip is selected this voltage will be removed so the line can be used as a clock for data exchange with the WiFi controller.
Separate pins for the Serial Debug Port (SDB) are available
WiFi Controller GPIO
GPIO0 - Output - On board LED. GPIO1 - Output - Power supply control. GPIO2 - Input - High if USB port or Pad 40 supplying power.
Power Supply
The Raspberry Pi Pico can be powered via the USB connector, or by supplying +5V to pin 39. The board had a diode that prevents power from pin 39 from flowing back to the USB socket, although the socket can be power via pin 30.
The Raspberry Pi Pico chip run on 3.3 volts. This is supplied by an onboard voltage regulator. This regulator can be disabled by pulling pin 37 to ground.
The regulator can run in two modes. By default the regulator runs in PFM mode which provides the best efficiency, but may be switched to PWM mode for improved ripple by outputting a one on the wireless chip’s GPIO1 (not the RP2040’s GPIO1).
Configurations
audiopack
NuttShell configuration (console enabled in UART0, at 115200 bps) with support for NXPlayer audio player.
composite
NuttShell configuration (console enabled in UART0, at 115200 bps) with support for CDC/ACM with MSC USB composite driver.
displaypack
NuttShell configuration (console enabled in USB Port, at 115200 bps) supporting ST7789 video display.
enc28j60
NuttShell configuration (console enabled in UART0, at 115200 bps) with support for NC28J60.
lcd1602
NuttShell configuration (console enabled in UART0, at 115200 bps) with support for LCD1602.
nsh
Basic NuttShell configuration (console enabled in UART0, at 115200 bps).
nsh-flash
Basic NuttShell configuration (console enabled in UART0, at 115200 bps with SMART flash filesystem.
nshsram
NuttShell configuration (console enabled in UART0, at 115200 bps) with interrupt vectors in RAM.
smp
Basic NuttShell configuration (console enabled in UART0, at 115200 bps) with both ARM cores enabled.
spisd
NuttShell configuration (console enabled in UART0, at 115200 bps) with SPI configured.
ssd1306
NuttShell configuration (console enabled in UART0, at 115200 bps) with support for ssd1306.
st7735
NuttShell configuration (console enabled in UART0, at 115200 bps) with support for st7735.
telnet
NuttShell configuration (console enabled in UART0, at 115200 bps) with WiFi client mode and both telnet server and client enabled.
After loading this configuration use make menuconfig to change the country code in Device Drivers->Wireless Device Support->IEEE 802.11 Device Support and the wireless configuration in Application Configuration->Network Utilities->Network initialization->WAPI Configuration to match your wireless network.
usbmsc
NuttShell configuration (console enabled in UART0, at 115200 bps) with support for usbmsc.
usbnsh
Basic NuttShell configuration (console enabled in USB Port, at 115200 bps).
README.txt
README
======
This directory contains the port of NuttX to the Raspberry Pi Pico.
See https://www.raspberrypi.org/products/raspberry-pi-pico/ for information
about Raspberry Pi Pico W
NuttX supports the following RP2040 capabilities:
- UART (console port)
- GPIO 0 (UART0 TX) and GPIO 1 (UART0 RX) are used for the console.
- I2C
- SPI (master only)
- DMAC
- PWM
- ADC
- Watchdog
- USB device
- MSC, CDC/ACM serial and these composite device are supported.
- CDC/ACM serial device can be used for the console.
- PIO (RP2040 Programmable I/O)
- Flash ROM Boot
- SRAM Boot
- If Pico SDK is available, nuttx.uf2 file which can be used in
BOOTSEL mode will be created.
- Persistent flash filesystem in unused flash ROM
- WiFi wireless communication
NuttX also provide support for these external devices:
- BMP180 sensor at I2C0 (don't forget to define I2C0 GPIOs at "I2C0 GPIO pin assign" in Board Selection menu)
- INA219 sensor / module (don't forget to define I2C0 GPIOs at "I2C0 GPIO pin assign" in Board Selection menu)
- Pico Display Pack (ST7789 LCD)
- RGB leds and buttons are not supported yet.
- Pico Audio Pack (PCM5100A I2S DAC)
- I2S interface is realized by PIO.
- WS2812 smart pixel support
There is currently no direct user mode access to these RP2040 hardware features:
- SPI Slave Mode
- SSI
- RTC
- Timers
Installation
============
1. Download Raspberry Pi Pico SDK and update submodule(cyw43-driver)
$ git clone -b 1.4.0 https://github.com/raspberrypi/pico-sdk.git
$ cd pico-sdk
$ git submodule update --init --recursive lib/cyw43-driver
2. Download and install picotool
Instructions can be found here: https://github.com/raspberrypi/picotool
If you are on Arch Linux, you can install the picotool through the AUR:
$ yay -S picotool
3. Set PICO_SDK_PATH environment variable
$ export PICO_SDK_PATH=<absolute_path_to_pico-sdk_directory>
4. Configure and build NuttX
$ git clone https://github.com/apache/nuttx.git nuttx
$ git clone https://github.com/apache/nuttx-apps.git apps
$ cd nuttx
$ make distclean
$ ./tools/configure.sh raspberrypi-pico:nsh
$ make V=1
5. Connect Raspberry Pi Pico board to USB port while pressing BOOTSEL.
The board will be detected as USB Mass Storage Device.
Then copy "nuttx.uf2" into the device.
(Same manner as the standard Pico SDK applications installation.)
6. To access the console, GPIO 0 and 1 pins must be connected to the
device such as USB-serial converter.
`usbnsh` configuration provides the console access by USB CDC/ACM serial
devcice. The console is available by using a terminal software on the USB
host.
Defconfigs
==========
- nsh
Minimum configuration with NuttShell
- nsh-flash
NuttX shell with SMART flash filesystem.
- nshsram
Load NuttX binary to SRAM
- smp
Enable SMP mode. Both Core 0 and Core 1 are used by NuttX.
- telnet
NuttShell configuration (console enabled in UART0, at 115200 bps) with
WiFi client mode and both telnet server and client enabled.
In order to use this configuration you must have RaspberryPi's pico-sdk
on your build system and have the PICO-SDK-PATH environment variable
set with the location of pico-sdk.
After loading this configuration use make menuconfig to change the
country code in Device Drivers->Wireless Device Support->IEEE 802.11
Device Support and the wireless configuration in Application
Configuration->Network Utilities->Network initialization->WAPI
Configuration to match your wireless network.
- ssd1306
SSD1306 OLED display (I2C) test configuration
Connection:
SSD1306 Raspberry Pi Pico
GND ----- GND (Pin 3 or 38 or ...)
VCC ----- 3V3 OUT (Pin 36)
SDA ----- GP4 (I2C0 SDA) (Pin 6)
SCL ----- GP5 (I2C0 SCL) (Pin 7)
- lcd1602
LCD 1602 Segment LCD Disaply (I2C)
Connection:
PCF8574 BackPack Raspberry Pi Pico
GND ----- GND (Pin 3 or 38 or ...)
VCC ----- 5V Vbus (Pin 40)
SDA ----- GP4 (I2C0 SDA) (Pin 6)
SCL ----- GP5 (I2C0 SCL) (Pin 7)
- spisd
SD card support (SPI connection)
Connection:
SD card slot Raspberry Pi Pico
DAT2 (NC)
DAT3/CS ----- GP17 (SPI0 CSn) (Pin 22)
CMD /DI ----- GP19 (SPI0 TX) (Pin 25)
VDD ----- 3V3 OUT (Pin 36)
CLK/SCK ----- GP18 (SPI0 SCK) (Pin 24)
VSS ----- GND (Pin 3 or 38 or ...)
DAT0/DO ----- GP16 (SPI0 RX) (Pin 21)
DAT1 (NC)
* Card hot swapping is not supported.
- st7735
st7735 SPI LCD support
Connection:
st7735 Raspberry Pi Pico
GND ----- GND (Pin 3 or 38 or ...)
VCC ----- 5V Vbus (Pin 40)
SDA ----- GP15 (SPI1 TX) (Pin 20)
SCK ----- GP14 (SPI1 SCK) (Pin 19)
CS ----- GP13 (SPI1 CSn) (Pin 17)
AO(D/C) ----- GP12 (SPI1 RX) (Pin 16)
BL ----- GP11 (Pin 15)
RESET ----- GP10 (Pin 14)
- enc28j60
ENC28J60 SPI ethernet controller support
- IP address is configured by DHCP.
- DNS address is 8.8.8.8 (CONFIG_NETINIT_DNSIPADDR)
- NTP client is enabled.
Connection:
ENC28J60 Raspberry Pi Pico
GND ----- GND (Pin 3 or 38 or ...)
3.3 ----- 3V3 OUT (Pin 36)
SI ----- GP15 (SPI1 TX) (Pin 20)
SCK ----- GP14 (SPI1 SCK) (Pin 19)
CS ----- GP13 (SPI1 CSn) (Pin 17)
SO ----- GP12 (SPI1 RX) (Pin 16)
INT ----- GP11 (Pin 15)
RESET ----- GP10 (Pin 14)
- displaypack
Pico Display Pack support
See the following page for connection:
https://shop.pimoroni.com/products/pico-display-pack
- audiopack
Pico Audio Pack support
See the following page for connection:
https://shop.pimoroni.com/products/pico-audio-pack
SD card interface is also enabled.
- usbnsh
USB CDC/ACM serial console with NuttShell
- usbmsc
USB MSC and CDC/ACM support
`msconn` and `sercon` commands enable the MSC and CDC/ACM devices.
The MSC support provides the interface to the SD card with SPI,
so the SD card slot connection like spisd configuration is required.
- composite
USB composite device (MSC + CDC/ACM) support
`conn` command enables the composite device.
License exceptions
==================
The following files are originated from the files in Pico SDK.
So, the files are licensed under 3-Clause BSD same as Pico SDK.
- arch/arm/src/rp2040/rp2040_clock.c
- arch/arm/src/rp2040/rp2040_pll.c
- arch/arm/src/rp2040/rp2040_xosc.c
- These are created by referring the Pico SDK clock initialization.
- arch/arm/src/rp2040/rp2040_pio.c
- arch/arm/src/rp2040/rp2040_pio.h
- arch/arm/src/rp2040/rp2040_pio_instructions.h
- These provide the similar APIs to Pico SDK's hardware_pio APIs.
- arch/arm/src/rp2040/hardware/*.h
- These are generated from rp2040.svd originally provided in Pico SDK.