PicoBoy Color

The PicoBoy Color (PBC) is the further development of the popular PicoBoy handheld, now with a color display for even more gaming fun. Whether you want to learn programming, develop your own games or simply play, the PicoBoy Color offers a wide range of possibilities. Although the original PicoBoy remains a great starting point for beginners and school classes, the PicoBoy Color offers an enhanced gaming experience and new possibilities for those who want more.

Board Overview

Hardware

The PicoBoy Color [15] is a special mini sized RP2040 development board.

Features and Resources

Printed Circuit Board

5V/125~250㎃ 3.0~3.3V/100~150㎃

133㎒ 2㎆ 264㎅ USB-C 2×AAA UF2

RST BOOT USER UP|DOWN|LEFT|RIGHT|ENTER

RED YELLOW GREEN LCD PASSIVE

11 5 1 1 1

  • Dual core Arm Cortex-M0+ processor running up to 133㎒

  • 264㎅ on-chip SRAM

  • 2㎆ on-board QSPI flash with XIP capabilities

  • USB 1.1 controller (host/device)

  • On-board USB-C connector

  • On-board 3.3V DC-DC buck-boost converter with 250㎃ switch

  • On-board 2 AAA battery holder

  • On-board RESET button

  • On-board BOOT button

  • On-board 1 User joystick (5 keys)

  • On-board 2 User button

  • On-board 3 User LEDs

  • On-board 1 passive magnetic speaker

  • On-board 1.69-inch 240×280 pixels LCD, 65K colorful IPS (serial)

  • RGB565, 16-bit color depth

  • 1 RST signal to LCD controller

  • 1 C/D signal to LCD controller

  • 1 SPI controller for LCD

  • 1 I2C controller for external sensor

  • 5 PWM channels for LEDs, LCD backlight and speaker

  • 1 ADC analog inputs

  • 8 Programmable I/O (PIO) state machines for custom peripherals

  • 1 Watchdog timer peripheral

  • 1 Temperature sensor on-chip

Design Data

 PicoBoy Color

Positions

PicoBoy Color details

Front side:

  1. ST7789V
    1.69-inch 240×280 pixels 65K colorful IPS LCD
  2. User joystick
    UP, DOWN, LEFT, RIGHT, ENTER
  3. User keys
    momentary push buttons
  4. LED monochrome
    user LEDs for diagnostic (not power indicator)
  5. Magnetic Speaker
    3.0Vo-p (2.0~4.0V) @ 4,000㎐ with ≫65㏈A
  6. Solder Pads
    supports I2C0 (default), UART1, GPIO/PWM
  • S8050 (J3Y)
    SMD NPN Transistor 300㎽, 40V @ 500㎃, SOT-23

Back side:

  1. RP2040

  2. USB Type-C connector
    Supports USB1.1 hosts and slave devices
  3. Power Supply Switch
  4. RESET and BOOT button
    press it when resetting to enter download mode
  5. W25Q16JV
    2㎆ NOR-Flash
  6. AAA
    2×1.5V @ 1,200㎃h battery holder


  • TX4310B (N1IF)
    150㎃ DC-DC buck-boost converter, power switch for 3.3V

Data Sheets

Flash partitions

QSPI NOR-Flash

bootrom

code_partition

storage_partition

primary 2㎆

256B

1㎆ - 256B

1㎆

Pinouts

The peripherals of the RP2040 SoC [33] can be routed to various pins on the board. The configuration of these routes can be modified through DTS. Please refer to the datasheet to see the possible routings for each peripheral. The default assignments for the on-board wiring is defined below. There are solder pads with additional signals routed to outside of the board.

Pin Mapping
on-board:

11 5 1 1 1

on-board:

1 RST 1 BOOT 2 USER 1 CURSOR 1 RED 1 YELLOW 1 GREEN 1 LCD 1 PASSIVE

Default Zephyr On-Board Mapping

 

Buttons

  • ENTER : GP0 (PWM0)
  • RIGHT : GP1 (PWM1)
  • DOWN : GP2 (PWM2)
  • LEFT : GP3 (PWM3)
  • UP : GP4 (PWM4)
  • BACK : GP27 (PWM11)
  • FORWARD : GP28 (PWM12)

LEDs

  • GREEN : GP12 PWM12
  • YELLOW : GP13 PWM13
  • RED : GP14 PWM14

Display and Speaker

  • n.c. : GP5 (PWM5)
  • n.c. : GP6 (PWM6)
  • n.c. : GP7 (PWM7)
  • LCD : GP8 (PWM8)
    on-board LCD data/cmd LCD_DC
  • LCD : GP9 (PWM9)
    on-board LCD reset LCD_RST
  • LCD : GP10 (PWM10)
    on-board LCD chip select LCD_CS
  • n.c. : GP11 (PWM11)
  • PASSIVE : GP15 PWM15
  • n.c. SPI0_RX : GP16 (PWM0)
  • n.c. SPI0_CSN : GP17 (PWM1)
  • LCD SPI0_SCK : GP18 (PWM2)
    on-board LCD i/f clock LCD_CLK
  • LCD SPI0_TX : GP19 (PWM3)
    on-board LCD i/f data LCD_DIN
  • LCD GPIO26 : GP26 (PWM10)
    on-board LCD backlight LCD_BL

Sensors via solder pads

  • I2C0_SDA : (UART1_TX) : GP20 (PWM4)
    on-board solder pads i/f data I2C_SDA
    on-board solder pads i/f data UART_TX
  • I2C0_SCL : (UART1_RX) : GP21 (PWM5)
    on-board solder pads i/f clock I2C_SCL
    on-board solder pads i/f data UART_RX

GPIO and ADC

  • n.c. : GP22 (PWM6)
  • n.c. : GP23 (PWM7)
  • n.c. : GP24 (PWM8)
  • n.c. : GP25 (PWM9)
  • n.c. ADC_CH3 : GP29 (PWM13)

Supported Features

Similar to the Raspberry Pi Pico the board configuration supports the following hardware features:

Hardware Features Supported by Zephyr

Peripheral

Kconfig option

Devicetree compatible

Zephyr API

PINCTRL

CONFIG_PINCTRL

raspberrypi,pico-pinctrl

Pin Control API

GPIO

CONFIG_GPIO

raspberrypi,pico-gpio

General-Purpose Input/Output (GPIO)

UART

CONFIG_SERIAL
raspberrypi,pico-uart
arm,pl011

Universal Asynchronous Receiver-Transmitter (UART)

UDC (USB Device Controller)

CONFIG_USB_DEVICE_STACK_NEXT

raspberrypi,pico-usbd

USB device support APIs

I2C

CONFIG_I2C

raspberrypi,pico-i2c

Inter-Integrated Circuit (I2C) Bus

SPI

CONFIG_SPI
raspberrypi,pico-spi
arm,pl022

Serial Peripheral Interface (SPI) Bus

PWM

CONFIG_PWM

raspberrypi,pico-pwm

Pulse Width Modulation (PWM)

ADC

CONFIG_ADC

raspberrypi,pico-adc

Analog-to-Digital Converter (ADC)

Temperature (Sensor)

CONFIG_SENSOR

raspberrypi,pico-temp

Sensors

RTC

CONFIG_RTC

raspberrypi,pico-rtc

Real-Time Clock (RTC)

Timer (Counter)

CONFIG_COUNTER

raspberrypi,pico-timer

Counter

Watchdog Timer (WDT)

CONFIG_WATCHDOG

raspberrypi,pico-watchdog

Watchdog

Flash

CONFIG_FLASH

raspberrypi,pico-flash-controller

Flash and Flash map

PIO

CONFIG_PIO_RPI_PICO

raspberrypi,pico-pio

N/A

UART (PIO)

CONFIG_SERIAL

raspberrypi,pico-uart-pio

Universal Asynchronous Receiver-Transmitter (UART)

SPI (PIO)

CONFIG_SPI

raspberrypi,pico-spi-pio

Serial Peripheral Interface (SPI) Bus

WS2812 (PIO)

CONFIG_LED_STRIP

worldsemi,ws2812-rpi-pico-pio

N/A

DMA

CONFIG_DMA

raspberrypi,pico-dma

Direct Memory Access (DMA)

HWINFO

CONFIG_HWINFO

N/A

Hardware Information

VREG

CONFIG_REGULATOR

raspberrypi,core-supply-regulator

Regulators

RESET

CONFIG_RESET

raspberrypi,pico-reset

Reset Controller

CLOCK

CONFIG_CLOCK_CONTROL
raspberrypi,pico-clock-controller
raspberrypi,pico-clock

Clock Control

NVIC

N/A

arm,v6m-nvic

Nested Vector Interrupts Controller

SYSTICK

N/A

arm,armv6m-systick

Other hardware features are not currently supported by Zephyr. The default configuration can be found in the following Kconfig file:

Board Configurations

The board can be configured only for the following single use cases.

west build -b picoboy_color/rp2040

Use the native USB device port with CDC-ACM as Zephyr console and for the shell.

Connections and IOs

The PicoBoy Color [16] website has detailed information about board connections. Download the different datasheets there or as linked above on the positions for more details.

System Clock

The RP2040 [33] MCU is configured to use the 12㎒ external crystal with the on-chip PLL generating the 125㎒ system clock.

GPIO (PWM) Ports

The RP2040 [33] MCU has 1 GPIO cell which covers all I/O pads and 8 PWM function unit each with 2 channels beside a dedicated Timer unit. Only 5 PWM channels are available, for the LCD backlight, the three user LEDs and the passive magnetic speaker.

ADC/TS Ports

The RP2040 [33] MCU has 1 ADC with 4 channels and an additional fifth channel for the on-chip temperature sensor (TS). The ADC channels 0-3 are not available for any on-board function.

The external voltage reference ADC_VREF is directly connected to the 3.3V power supply.

SPI Port

The RP2040 [33] MCU has 2 SPIs. The serial bus SPI0 is connect to the on-board LCD over GP19 (MOSI), GP16 (MISO), GP18 (SCK), and GP17 (CSn), but only MOSI and SCK is used for write-only communication. The display chip-select signal will driven as simple GPIO by GP10 and the display itself does not provide any data out signal (MISO).

SPI1 is not available in any default setup.

I2C Port

The RP2040 [33] MCU has 2 I2Cs. The serial bus I2C0 is connect to the on-board solder pads over GP20 (I2C0_SDA), GP21 (I2C0_SCL). I2C1 is not available in any default setup.

PicoBoy Color I2C Port

There is no on-board acceleration sensor. The I2C port cannot be used at the same time as the UART port. Both share the required lines on GP20 and GP21.

The I2C port on solder pads is enabled by default.

Serial Port

The RP2040 [33] MCU has 2 UARTs.

PicoBoy Color UART Port

The serial port UART1 is connect to the on-board solder pads over GP20 (UART1_TX), GP21 (UART1_RX). UART0 is not available in any default setup. The UART port cannot be used at the same time as the I2C port. Both share the required lines on GP20 and GP21.

The UART port on solder pads is disabled by default.

USB Device Port

The RP2040 [33] MCU has a (native) USB device port that can be used to communicate with a host PC. See the USB sample applications for more, such as the USB CDC ACM UART sample sample which sets up a virtual serial port that echos characters back to the host PC. The board provide the Zephyr console per default on the USB port as CDC ACM:

USB device idVendor=2e8a, idProduct=000a, bcdDevice= 4.05
USB device strings: Mfr=1, Product=2, SerialNumber=3
Product: PicoBoy Color (CDC ACM)
Manufacturer: JSED (Raspberry Pi)
SerialNumber: B69CA314D5626E5B

Programmable I/O (PIO)

The RP2040 SoC [33] comes with two PIO periherals. These are simple co-processors that are designed for I/O operations. The PIOs run a custom instruction set, generated from a custom assembly language. PIO programs are assembled using pioasm, a tool provided by Raspberry Pi. Further information can be found in the Raspberry Pi Pico C/C++ SDK [10] document, section with title “Using PIOASM, the PIO Assembler”.

Zephyr does not (currently) assemble PIO programs. Rather, they should be manually assembled and embedded in source code. An example of how this is done can be found at drivers/serial/uart_rpi_pico_pio.c or drivers/spi/spi_rpi_pico_pio.c.

Programming and Debugging

Flashing

The board can only be flashed with a UF2 file. There is no SWD connector.

Using UF2

By default, building an application for the board will generate a build/zephyr/zephyr.uf2 file. If the board is powered on with the BOOTSEL button pressed, it will appear on the host as a mass storage device:

USB device idVendor=2e8a, idProduct=0003, bcdDevice= 1.00
USB device strings: Mfr=1, Product=2, SerialNumber=0
Product: RP2 Boot
Manufacturer: Raspberry Pi
SerialNumber: E0C9125B0D9B

The UF2 file should be drag-and-dropped or copied on command line to the device, which will then flash the board.

RP2040 Boot-ROM

Each RP2040 SoC [33] ships the UF2 compatible [6] bootloader pico-bootrom-rp2040 [12], a native support in silicon. The full source for the RP2040 bootrom at pico-bootrom-rp2040 [12] includes versions B0, B1 and B2 of the bootrom, which correspond to the same silicon revisions, respectively.

Note that every time you build a program for the RP2040, the Pico SDK selects an appropriate second stage bootloader based on what kind of external QSPI Flash type the board configuration you are building for was giving. There are several versions of boot2 [11] for different flash chips, and each one is exactly 256 bytes of code which is put right at the start of the eventual program binary. On Zephyr the boot2 versions are part of the Raspberry Pi Pico HAL [14] module. Possible selections:

CONFIG_RP2_FLASH_AT25SF128A:

boot2_at25sf128a.S [36]

CONFIG_RP2_FLASH_GENERIC_03H:

boot2_generic_03h.S [37]

CONFIG_RP2_FLASH_IS25LP080:

boot2_is25lp080.S [38]

CONFIG_RP2_FLASH_W25Q080:

boot2_w25q080.S [39]

CONFIG_RP2_FLASH_W25X10CL:

boot2_w25x10cl.S [40]

The board set this option to CONFIG_RP2_FLASH_W25Q080.

Further information can be found in the RP2040 Datasheet [34], sections with title “Bootrom” and “Processor Controlled Boot Sequence” or Brian Starkey’s Blog article Pico serial bootloader [13]

Debugging

The board does not provide any SWD connector, thus debugging software is not possible.

Basic Samples

LED Blinky and Fade

Red User LED Blinky by GPIO

See also Zephyr sample: Blinky.

west build -b picoboy_color/rp2040 -p -d build/picoboy_color zephyr/samples/basic/blinky
west flash -d build/picoboy_color

Red User LED Blinky by PWM

See also Zephyr sample: PWM Blinky.

west build -b picoboy_color/rp2040 -p -d build/picoboy_color zephyr/samples/basic/blinky_pwm
west flash -d build/picoboy_color

All User LED Fade by PWM

See also Zephyr sample: Fade LED.

west build -b picoboy_color/rp2040 -p -d build/picoboy_color zephyr/samples/basic/fade_led
west flash -d build/picoboy_color

Red User LED On/Off by GPIO Button (left side user button BACK)

See also Zephyr sample: Button.

west build -b picoboy_color/rp2040 -p -d build/picoboy_color zephyr/samples/basic/button
west flash -d build/picoboy_color

Hello Shell on USB-CDC/ACM Console

Hello Shell

See also Bridle sample: Hello Shell.

west build -b picoboy_color/rp2040 -p -d build/picoboy_color bridle/samples/helloshell
west flash -d build/picoboy_color

Simple test execution on target

(text in bold is a command input)

uart:~$ hello -h
hello - say hello
uart:~$ hello
Hello from shell.
uart:~$ hwinfo devid
Length: 8
ID: 0xb69ca314d5626e5b

uart:~$ kernel version
Zephyr version 4.5.0-rc1

uart:~$ bridle version
Bridle version 4.4.99

uart:~$ bridle version long
Bridle version 4.4.99.0

uart:~$ bridle info
Zephyr: 4.5.0-rc1
Bridle: 4.4.99
uart:~$ device list
devices:
- clock-controller@40008000 (READY)
  DT node labels: clocks
- reset-controller@4000c000 (READY)
  DT node labels: reset
- cdc_acm_console_uart (READY)
  DT node labels: cdc_acm_console_uart
- timer@40054000 (READY)
  DT node labels: timer
- watchdog@40058000 (READY)
  DT node labels: wdt0
- dma@50000000 (READY)
  DT node labels: dma
- gpio-port@0 (READY)
  DT node labels: gpio0
- usbd@50110000 (READY)
  DT node labels: usbd zephyr_udc0
- adc@4004c000 (READY)
  DT node labels: adc
- flash-controller@18000000 (READY)
  DT node labels: ssi
- i2c@40044000 (READY)
  DT node labels: i2c0 zephyr_i2c
- pwm@40050000 (READY)
  DT node labels: pwm
- vreg@40064000 (READY)
  DT node labels: vreg
- rtc@4005c000 (READY)
  DT node labels: rtc
- lcd-backlight-en (READY)
  DT node labels: lcd_backlight_en
- pwm-leds (READY)
  DT node labels: pwm-leds
- dietemp (READY)
  DT node labels: die_temp
uart:~$ history
[  0] history
[  1] device list
[  2] bridle info
[  3] bridle version long
[  4] bridle version
[  5] kernel version
[  6] hwinfo devid
[  7] hello
[  8] hello -h

More Samples

Sounds from the speaker on USB-CDC/ACM Console

The sample is prepared for the on-board PWM_SPEAKER connected to the PWM channel at GP15 / PWM15 (PWM7CHB).

The PWM period is 880 ㎐, twice the concert pitch frequency of 440 ㎐.

PicoBoy Color Speaker Test

Speaker Test

Invoke west build and west flash:

west build -b picoboy_color/rp2040 -p -d build/picoboy_color bridle/samples/buzzer
west flash -d build/picoboy_color

Simple test execution on target

  1. play a beep

  2. play a folk song

  3. play a chrismas song

uart:~$ buzzer beep
uart:~$ buzzer play folksong
uart:~$ buzzer play xmastime

Input dump on USB-CDC/ACM Console

Print the input events related to the five on-board joystick keys using the Input subsystem API. That are:

BACK : zephyr,code = <INPUT_KEY_BACK>;
FORWARD : zephyr,code = <INPUT_KEY_FORWARD>;
UP : zephyr,code = <INPUT_KEY_UP>;
DOWN : zephyr,code = <INPUT_KEY_DOWN>;
LEFT : zephyr,code = <INPUT_KEY_LEFT>;
RIGHT : zephyr,code = <INPUT_KEY_RIGHT>;
ENTER : zephyr,code = <INPUT_KEY_ENTER>;

See also Zephyr sample: Input dump.

Joystick Test

west build -b picoboy_color/rp2040 -p -d build/picoboy_color zephyr/samples/subsys/input/input_dump
west flash -d build/picoboy_color

Simple logging output on target

*** Booting Zephyr OS build v4.5.0-rc1…***
Input sample started
I: input event: dev=gpio-keys        SYN type= 1 code=158 value=1
I: input event: dev=gpio-keys        SYN type= 1 code=158 value=0
I: input event: dev=gpio-keys        SYN type= 1 code=159 value=1
I: input event: dev=gpio-keys        SYN type= 1 code=159 value=0
I: input event: dev=gpio-keys        SYN type= 1 code=103 value=1
I: input event: dev=gpio-keys        SYN type= 1 code=103 value=0
I: input event: dev=gpio-keys        SYN type= 1 code=108 value=1
I: input event: dev=gpio-keys        SYN type= 1 code=108 value=0
I: input event: dev=gpio-keys        SYN type= 1 code=105 value=1
I: input event: dev=gpio-keys        SYN type= 1 code=105 value=0
I: input event: dev=gpio-keys        SYN type= 1 code=106 value=1
I: input event: dev=gpio-keys        SYN type= 1 code=106 value=0
I: input event: dev=gpio-keys        SYN type= 1 code= 28 value=1
I: input event: dev=gpio-keys        SYN type= 1 code= 28 value=0

Display Test and Demonstration

The following samples work with the chosen display. That is:

LCD : chosen { zephyr,display = &lcd_panel; };
ST7789V : lcd_panel: &st7789v_240x280 {};

Devicetree compatible

  • zephyr,lvgl-button-input with devicetree relation lvgl_buttons: lvgl-buttons { input = <&gpio_keys>; };

    FORWARD : input-codes = <INPUT_KEY_FORWARD>; : coordinates = <120 140>; (center of LCD)

  • zephyr,lvgl-keypad-input with devicetree relation lvgl_keypad: lvgl-keypad { input = <&gpio_keys>; };

    UP : input-codes = <INPUT_KEY_UP>; : lvgl-codes = <LV_KEY_UP>;
    DOWN : input-codes = <INPUT_KEY_DOWN>; : lvgl-codes = <LV_KEY_DOWN>;
    LEFT : input-codes = <INPUT_KEY_LEFT>; : lvgl-codes = <LV_KEY_LEFT>;
    RIGHT : input-codes = <INPUT_KEY_RIGHT>; : lvgl-codes = <LV_KEY_RIGHT>;
    ENTER : input-codes = <INPUT_KEY_ENTER>; : lvgl-codes = <LV_KEY_ENTER>;

LCD Orientation and Bit Order Test

PicoBoy Color Display Test

Draw some basic rectangles onto the display using the Display driver API. See also Zephyr sample: Display.

west build -b picoboy_color/rp2040 -p -d build/picoboy_color zephyr/samples/drivers/display
west flash -d build/picoboy_color

LVGL Basic Sample

Displays “Hello World!” in the center of the screen and a counter at the bottom which increments every second using the LVGL module on top of the Display driver API. See also Zephyr sample: LVGL basic sample.

west build -b picoboy_color/rp2040 -p -d build/picoboy_color zephyr/samples/subsys/display/lvgl
west flash -d build/picoboy_color

This sample comes with a Shell command line access to the LVGL backend on the console, here configured for a USB console:

Simple test execution on target

uart:~$ lvgl
lvgl - LVGL shell commands
Subcommands:
  stats   : Show LVGL statistics
  monkey  : LVGL monkey testing

uart:~$ lvgl stats
stats - Show LVGL statistics
Subcommands:
  memory  : Show LVGL memory statistics
            Usage: memory [-c]
                   -c  dump chunk information

uart:~$ lvgl stats memory
Heap at 0x200016d0 contains 2047 units in 11 buckets

  bucket#    min units        total      largest      largest
             threshold       chunks      (units)      (bytes)
  -----------------------------------------------------------
        0            1            1            1            8
        1            2            3            3           24
        9          512            1          950         7600

7644 free bytes, 8136 allocated bytes, overhead = 600 bytes (3.7%)
uart:~$ device list
devices:
- clock-controller@40008000 (READY)
  DT node labels: clocks
- reset-controller@4000c000 (READY)
  DT node labels: reset
- cdc_acm_console_uart (READY)
  DT node labels: cdc_acm_console_uart
- timer@40054000 (READY)
  DT node labels: timer
- watchdog@40058000 (READY)
  DT node labels: wdt0
- dma@50000000 (READY)
  DT node labels: dma
- gpio-port@0 (READY)
  DT node labels: gpio0
- usbd@50110000 (READY)
  DT node labels: usbd zephyr_udc0
- pwm@40050000 (READY)
  DT node labels: pwm
- vreg@40064000 (READY)
  DT node labels: vreg
- spi@4003c000 (READY)
  DT node labels: spi0
- lcd-backlight-en (READY)
  DT node labels: lcd_backlight_en
- mipi-dbi-spi0 (READY)
  DT node labels: mipi_dbi_spi0
- st7789v-240x28@0 (READY)
  DT node labels: st7789v_240x280 lcd_panel
- gpio-keys (READY)
  DT node labels: gpio_keys
- lvgl-buttons (READY)
  DT node labels: lvgl_buttons
- lvgl-keypad (READY)
  DT node labels: lvgl_keypad

References