walnux/Documentation/platforms/arm/rp2040/boards/waveshare-rp2040-lcd-1.28/index.rst

===============================
Waveshare RP2040 LCD 1.28
===============================

.. tags:: chip:rp2040

The `Waveshare RP2040 LCD 1.28 <https://www.waveshare.com/wiki/RP2040-LCD-1.28>`_
is a low-cost, high-performance MCU board designed by Waveshare based on RP2040
with onboard 1.28 inch LCD.

.. figure:: RP2040-LCD-1.28.jpg
   :align: center

Features
========

* RP2040 MCU chip designed by Raspberry Pi in the United Kingdom
* Dual-core Arm Cortex M0+ processor, flexible clock running up to 133 MHz
* 264KB of SRAM, and 2MB of onboard Flash memory
* Type-C connector, keeps it up to date, easier to use
* Onboard 1.28-inch 240 x 240 resolution, 65K RGB IPS LCD display for clear color pictures
* Lithium battery recharge/discharge header, suitable for mobile devices
* All GPIOs are adapted through 1.27 pitch female headers
  (There are 30 pins in total, but some pins have been connected to the internal circuit,
  you need to pay attention when multiplexing, please refer to the wiki for details)
* USB 1.1 with device and host support
* Low-power sleep and dormant modes
* Drag-and-drop programming using mass storage over USB
* 2 x SPI, 2 x I2C, 2 x UART, 2 x UART, 4 x 12-bit ADC, 16 x controllable PWM channels
* Accurate clock and timer on-chip
* Temperature sensor
* Accelerated floating-point libraries on-chip
* 8 x Programmable I/O (PIO) state machines for custom peripheral support

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.

Buttons and LEDs
================

No user LED is provided.

A BOOT button, which if held down when pressing RESET or power is first
applied to the board, will cause the RP2040 to boot into programming
mode and appear as a storage device to a computer connected via USB.
Saving a .UF2 file to this device will replace the Flash ROM contents
on the RP2040.

Pin Mapping
===========

===== ========== ==========
Pad   Signal     Notes
===== ========== ==========
2     GPIO0      Default TX for UART0 serial console
4     GPIO1      Default RX for UART0 serial console
===== ========== ==========

Power Supply
============

The Raspberry Pi Pico can be powered via the USB connector, connecting
a lithium battery through connector, or by supplying +5V to pin 18(VSYS).
The board had a diode that prevents power from pin 18 from flowing back
to the USB socket. Power through USB or VSYS will be charging the battery
if connected. The schematic is available at `RP2040-LCD-1.28-sch.pdf <https://www.waveshare.net/w/upload/6/60/RP2040-LCD-1.28-sch.pdf>`_

Supported Capabilities
======================

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

There is currently no direct user mode access to these RP2040 hardware features:

* SPI Slave Mode
* SSI
* RTC
* Timers

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)
* SHT4X sensor at I2C0
* WS2812 smart pixel support

Installation
============

1. Download Raspberry Pi Pico SDK

.. code-block:: console

  $ git clone -b 2.0.0 https://github.com/raspberrypi/pico-sdk.git

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:

.. code-block:: console

  $ yay -S picotool

3. Set PICO_SDK_PATH environment variable

.. code-block:: console

  $ export PICO_SDK_PATH=<absolute_path_to_pico-sdk_directory>

4. Configure and build NuttX

.. code-block:: console

  $ 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 waveshare-rp2040-lcd-1.28:nsh
  $ make V=1

5. Connect the Waveshare RP2040 board to USB port while pressing BOOT.
   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
   decive.  The console is available by using a terminal software on the USB
   host.

Configurations
==============

composite
---------

NuttShell configuration (console enabled in UART0, at 115200 bps) with support for
CDC/ACM with MSC USB composite driver. ``conn`` command enables the composite
device.

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 SD
card support enabled.

.. list-table:: spisd connections
   :widths: auto
   :header-rows: 1

   * - SD card slot
     - Waveshare RP2040
   * - DAT2          
     - Not connected
   * - 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          
     - Not connected

Card hot swapping is not supported.

usbmsc
------

NuttShell configuration (console enabled in UART0, at 115200 bps) with support for
USB MSC and CDC/ACM.

``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.

usbnsh
------

Basic NuttShell configuration using CDC/ACM serial (console enabled in USB Port,
at 115200 bps).

fb
------------------

NuttShell configuration (console enabled in USB Port, at 115200 bps) with support for
gc9a01 and video framebuffer example.

lvgl
-----------------

NuttShell configuration (console enabled in USB Port, at 115200 bps) with support for
gc9a01 and LVGL demo (using lcd_dev).

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.