Inkplate 6Color

Board Overview

Inkplate 6Color

Name:

inkplate_6color

Vendor:

Soldered Electronics

Status:

Not actively maintained

Architecture:

xtensa

SoC:

esp32

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Overview

The Inkplate 6Color is an ESP32-based development board featuring a 5.85-inch 7-color e-paper display, designed and manufactured by Soldered Electronics [7]. It targets low-power, always-on visual applications such as dashboards, signage, information panels, and IoT displays.

The board combines an ESP32-WROVER-E module with a high-resolution color e-paper panel and on-board peripherals including an RTC, microSD storage, battery monitoring, and a GPIO expander. The e-paper display retains its image without power between refreshes, enabling extremely low average power consumption in battery-operated deployments.

For more information, check Inkplate 6Color [6].

Hardware

The Inkplate 6Color is built around the ESP32-WROVER-E module (4 MB flash, 8 MB PSRAM) and includes the following additional on-board components:

• 5.85-inch 7-color e-paper display (600 × 448 pixels)

• PCAL6416A 16-bit I2C GPIO expander

• PCF85063A real-time clock with battery backup

• MicroSD card slot (SPI)

• Battery voltage monitor (ADC)

• Wake-up button (active low)

• easyC I2C expansion connector

• USB-C connector for power and programming

• JST battery connector

ESP32 Features

• Dual core Xtensa microprocessor (LX6), running at 160 or 240MHz

• 520KB of SRAM

• 802.11b/g/n/e/i

• Bluetooth v4.2 BR/EDR and BLE

• Various peripherals:

  • 12-bit ADC with up to 18 channels

  • 2x 8-bit DACs

  • 10x touch sensors

  • 4x SPI

  • 2x I2S

  • 2x I2C

  • 3x UART

  • SD/SDIO/MMC host

  • Slave (SDIO/SPI)

  • Ethernet MAC

  • CAN bus 2.0

  • IR (RX/TX)

  • Motor PWM

  • LED PWM with up to 16 channels

  • Hall effect sensor

  • Temperature sensor

• Cryptographic hardware acceleration (RNG, ECC, RSA, SHA-2, AES)

• 5uA deep sleep current

Asymmetric Multiprocessing (AMP)

Boards featuring the ESP32 and ESP32-S3 SoC allows 2 different applications to be executed. Due to its dual-core architecture, each core can be enabled to execute customized tasks in stand-alone mode and/or exchanging data over OpenAMP framework. See Inter-Processor Communication (IPC) folder as code reference.

Note

** AMP and serial output support **

In the current Zephyr ESP32 implementation, access to Zephyr-managed serial drivers (such as printk(), logging, or the console UART) is not yet implemented for applications running on the APPCPU. As a result, serial output APIs provided by Zephyr are only available on the PROCPU.

As a mitigation, applications running on the APPCPU may use ESP32 ROM functions such as ets_printf() to emit diagnostic or debug output.

For more information, check the ESP32 Datasheet [1] or the ESP32 Technical Reference Manual [2].

Connections and IOs

Internal I2C Bus (Bus 0):

Device	Address	Function
PCAL6416A	0x20	16-bit GPIO expander
PCF85063A	0x51	Real-time clock

GPIO Assignments:

GPIO	Function	Usage
GPIO1	UART0_TX	Console UART transmit
GPIO3	UART0_RX	Console UART receive
GPIO12	SPI2_MISO	SD card SPI interface
GPIO13	SPI2_MOSI	SD card SPI interface
GPIO14	SPI2_SCLK	SD card SPI clock
GPIO15	SPI2_CS	SD card chip select
GPIO21	I2C0_SDA	External I2C data (easyC)
GPIO22	I2C0_SCL	External I2C clock (easyC)
GPIO26	I2C1_SDA	Internal I2C data
GPIO27	SPI3_MOSI	E-paper display interface
GPIO32	I2C1_SCL	Internal I2C clock
GPIO36	Wake Button	User wake-up button (active low)
GPIO39	RTC Interrupt	PCF85063A interrupt output

Supported Features

The inkplate_6color board supports the hardware features listed below.

on-chip / on-board

Feature integrated in the SoC / present on the board.

2 / 2

Number of instances that are enabled / disabled.
Click on the label to see the first instance of this feature in the board/SoC DTS files.

vnd,foo

Compatible string for the Devicetree binding matching the feature.
Click on the link to view the binding documentation.

inkplate_6color/esp32/appcpu target

Type	Location	Description	Compatible
CPU	on-chip	Espressif Xtensa LX6 CPU2	espressif,xtensa-lx6
ADC	on-chip	ESP32 ADC2	espressif,esp32-adc
Bluetooth	on-chip	Bluetooth HCI for Espressif ESP321	espressif,esp32-bt-hci
CAN	on-chip	ESP32 Two-Wire Automotive Interface (TWAI)1	espressif,esp32-twai
Clock control	on-chip	ESP32 Clock (Power & Clock Controller Module) Module1	espressif,esp32-clock
Counter	on-chip	ESP32 Counter Driver based on RTC Main Timer1	espressif,esp32-rtc-timer
	on-chip	ESP32 general-purpose timers4	espressif,esp32-timer
	on-chip	ESP32 counters4	espressif,esp32-counter
Cryptographic accelerator	on-chip	Espressif ESP32 SHA Hardware Accelerator1	espressif,esp32-sha
	on-chip	Espressif ESP32 family AES Hardware Accelerator1	espressif,esp32-aes
DAC	on-chip	ESP32 Digital to Analog converter (DAC)1	espressif,esp32-dac
Ethernet	on-chip	ESP32 Ethernet1	espressif,esp32-eth
	on-chip	ESP32 MDIO controller1	espressif,esp32-mdio
Flash controller	on-chip	ESP32 flash controller1	espressif,esp32-flash-controller
GPIO & Headers	on-chip	ESP32 GPIO controller2	espressif,esp32-gpio
I2C	on-chip	ESP32 I2C2	espressif,esp32-i2c
I2S	on-chip	ESP32 I2S2	espressif,esp32-i2s
Input	on-chip	ESP32 touch sensor input1	espressif,esp32-touch
Interrupt controller	on-chip	ESP32 Interrupt controller1	espressif,esp32-intc
IPM	on-chip	ESP32 soft inter processor message1	espressif,esp32-ipm
Mailbox	on-chip	ESP32 soft mailbox1	espressif,mbox-esp32
Memory controller	on-chip	ESP32 pseudo-static RAM controller1	espressif,esp32-psram
MTD	on-chip	Flash node1	soc-nv-flash
	on-chip	Fixed partitions of a flash (or other non-volatile storage) memory1	fixed-partitions
Pin control	on-chip	ESP32 pin controller1	espressif,esp32-pinctrl
PWM	on-chip	ESP32 LED Control (LEDC)1	espressif,esp32-ledc
	on-chip	ESP32 Motor Control Pulse Width Modulator (MCPWM)2	espressif,esp32-mcpwm
RNG	on-chip	ESP32 TRNG (True Random Number Generator)1	espressif,esp32-trng
SDHC	on-chip	ESP32 SDHC controller1	espressif,esp32-sdhc
	on-chip	ESP32 SDHC controller slot2	espressif,esp32-sdhc-slot
Sensors	on-chip	ESP32 Pulse Counter (PCNT)1	espressif,esp32-pcnt
Serial controller	on-chip	ESP32 UART3	espressif,esp32-uart
SPI	on-chip	ESP32 SPI controller2	espressif,esp32-spi
SRAM	on-chip	Generic on-chip SRAM2	mmio-sram
Watchdog	on-chip	ESP32 watchdog11	espressif,esp32-watchdog
Wi-Fi	on-chip	ESP32 SoC Wi-Fi1	espressif,esp32-wifi

inkplate_6color/esp32/procpu target

Type	Location	Description	Compatible
CPU	on-chip	Espressif Xtensa LX6 CPU2	espressif,xtensa-lx6
ADC	on-chip	ESP32 ADC11	espressif,esp32-adc
Bluetooth	on-chip	Bluetooth HCI for Espressif ESP321	espressif,esp32-bt-hci
CAN	on-chip	ESP32 Two-Wire Automotive Interface (TWAI)1	espressif,esp32-twai
Clock control	on-chip	ESP32 Clock (Power & Clock Controller Module) Module1	espressif,esp32-clock
Counter	on-chip	ESP32 Counter Driver based on RTC Main Timer1	espressif,esp32-rtc-timer
	on-chip	ESP32 general-purpose timers4	espressif,esp32-timer
	on-chip	ESP32 counters4	espressif,esp32-counter
Cryptographic accelerator	on-chip	Espressif ESP32 SHA Hardware Accelerator1	espressif,esp32-sha
	on-chip	Espressif ESP32 family AES Hardware Accelerator1	espressif,esp32-aes
DAC	on-chip	ESP32 Digital to Analog converter (DAC)1	espressif,esp32-dac
Display	on-board	E-Ink AC057TC1 Display Controller1	eink,ac057tc1
Ethernet	on-chip	ESP32 Ethernet1	espressif,esp32-eth
	on-chip	ESP32 MDIO controller1	espressif,esp32-mdio
Flash controller	on-chip	ESP32 flash controller1	espressif,esp32-flash-controller
GPIO & Headers	on-chip	ESP32 GPIO controller2	espressif,esp32-gpio
	on-board	PCAL6416A 16-bit I2C-based I/O expander1	nxp,pcal6416a
	on-board	EasyC is a 4-pin JST connector for I2C devices1	solderedelectronics,easyc-connector
I2C	on-chip	ESP32 I2C11	espressif,esp32-i2c
I2S	on-chip	ESP32 I2S2	espressif,esp32-i2s
IIO	on-board	Voltage Divider1	voltage-divider
Input	on-chip	ESP32 touch sensor input1	espressif,esp32-touch
	on-board	Group of GPIO-bound input keys1	gpio-keys
Interrupt controller	on-chip	ESP32 Interrupt controller1	espressif,esp32-intc
IPM	on-chip	ESP32 soft inter processor message1	espressif,esp32-ipm
Mailbox	on-chip	ESP32 soft mailbox1	espressif,mbox-esp32
Memory controller	on-chip	ESP32 pseudo-static RAM controller1	espressif,esp32-psram
MTD	on-chip	Flash node1	soc-nv-flash
	on-chip	Fixed partitions of a flash (or other non-volatile storage) memory1	fixed-partitions
Pin control	on-chip	ESP32 pin controller1	espressif,esp32-pinctrl
PWM	on-chip	ESP32 LED Control (LEDC)1	espressif,esp32-ledc
	on-chip	ESP32 Motor Control Pulse Width Modulator (MCPWM)2	espressif,esp32-mcpwm
RNG	on-chip	ESP32 TRNG (True Random Number Generator)1	espressif,esp32-trng
RTC	on-board	NXP PCF85063A RTC1	nxp,pcf85063a
SDHC	on-chip	ESP32 SDHC controller1	espressif,esp32-sdhc
	on-chip	ESP32 SDHC controller slot2	espressif,esp32-sdhc-slot
Sensors	on-chip	ESP32 Pulse Counter (PCNT)1	espressif,esp32-pcnt
Serial controller	on-chip	ESP32 UART12	espressif,esp32-uart
SPI	on-chip	ESP32 SPI controller2	espressif,esp32-spi
SRAM	on-chip	Generic on-chip SRAM2	mmio-sram
Watchdog	on-chip	ESP32 watchdog11	espressif,esp32-watchdog
Wi-Fi	on-chip	ESP32 SoC Wi-Fi1	espressif,esp32-wifi

System Requirements

Binary Blobs

Espressif HAL requires RF binary blobs in order work. Run the command below to retrieve those files.

west blobs fetch hal_espressif

Note

It is recommended running the command above after west update.

Programming and Debugging

The inkplate_6color board supports the runners and associated west commands listed below.

	flash	debug	attach	debugserver	rtt
esp32	✅ (default)
openocd	✅	✅ (default)	✅	✅	✅

Simple Boot

The board could be loaded using the single binary image, without 2nd stage bootloader. It is the default option when building the application without additional configuration.

Note

Simple boot does not provide any security features nor OTA updates.

MCUboot Bootloader

User may choose to use MCUboot bootloader instead. In that case the bootloader must be built (and flashed) at least once.

There are two options to be used when building an application:

1. Sysbuild

2. Manual build

Note

User can select the MCUboot bootloader by adding the following line to the board default configuration file.

CONFIG_BOOTLOADER_MCUBOOT=y

Sysbuild

The sysbuild makes possible to build and flash all necessary images needed to bootstrap the board with the ESP32 SoC.

To build the sample application using sysbuild use the command:

west build -b <board> --sysbuild samples/hello_world

By default, the ESP32 sysbuild creates bootloader (MCUboot) and application images. But it can be configured to create other kind of images.

Build directory structure created by sysbuild is different from traditional Zephyr build. Output is structured by the domain subdirectories:

build/
├── hello_world
│   └── zephyr
│       ├── zephyr.elf
│       └── zephyr.bin
├── mcuboot
│    └── zephyr
│       ├── zephyr.elf
│       └── zephyr.bin
└── domains.yaml

Note

With --sysbuild option the bootloader will be re-build and re-flash every time the pristine build is used.

For more information about the system build please read the Sysbuild (System build) documentation.

Manual Build

During the development cycle, it is intended to build & flash as quickly possible. For that reason, images can be built one at a time using traditional build.

The instructions following are relevant for both manual build and sysbuild. The only difference is the structure of the build directory.

Note

Remember that bootloader (MCUboot) needs to be flash at least once.

Build and flash applications as usual (see Building an Application and Run an Application for more details).

# From the root of the zephyr repository
west build -b <board> samples/hello_world

The usual flash target will work with the board configuration. Here is an example for the Hello World application.

# From the root of the zephyr repository
west build -b <board> samples/hello_world
west flash

Open the serial monitor using the following command:

west espressif monitor

After the board has automatically reset and booted, you should see the following message in the monitor:

***** Booting Zephyr OS vx.x.x-xxx-gxxxxxxxxxxxx *****
Hello World! <board>

Board variants using Snippets

ESP32 boards can be assembled with different modules using multiple combinations of SPI flash sizes, PSRAM sizes and PSRAM modes. The snippets under snippets/espressif provide a modular way to apply these variations at build time without duplicating board definitions.

The following snippet-based variants are supported:

Snippet name	Description
Flash memory size
espressif-flash-4M	Board with 4MB of flash
espressif-flash-8M	Board with 8MB of flash
espressif-flash-16M	Board with 16MB of flash
espressif-flash-32M	Board with 32MB of flash
espressif-flash-64M	Board with 64MB of flash
espressif-flash-128M	Board with 128MB of flash
PSRAM memory size
espressif-psram-2M	Board with 2MB of PSRAM
espressif-psram-4M	Board with 4MB of PSRAM
espressif-psram-8M	Board with 8MB of PSRAM
PSRAM utilization
espressif-psram-reloc	Relocate flash to PSRAM
espressif-psram-wifi	Wi-Fi buffers in PSRAM

To apply a board variant, use the -S flag with west build:

west build -b <board> -S espressif-flash-32M -S espressif-psram-4M samples/hello_world

Note

These snippets are only applicable to boards with compatible hardware support for the selected flash/PSRAM configuration.

• If no FLASH snippet is used, the board default flash size will be used.

• If no PSRAM snippet is used, the board default psram size will be used.

Debugging

OpenOCD Debugging

Espressif chips require a custom OpenOCD build with ESP32-specific patches. Download the latest release from OpenOCD for ESP32 [3].

For detailed JTAG setup instructions, see JTAG debugging for ESP32 [5].

Zephyr Thread Awareness

OpenOCD supports Zephyr RTOS thread awareness, allowing GDB to:

• List all threads with info threads

• Display thread names, priorities, and states

• Switch between thread contexts

• Show backtraces for any thread

Requirements:

• OpenOCD ESP32 v0.12.0-esp32-20251215 [4] or later

• Build with CONFIG_DEBUG_THREAD_INFO=y

Example:

# From the root of the zephyr repository
west build -b <board> samples/hello_world -- -DCONFIG_DEBUG_THREAD_INFO=y -DOPENOCD=<path/to/bin/openocd> -DOPENOCD_DEFAULT_PATH=<path/to/openocd/share/openocd/scripts>
west debug

Using a Custom OpenOCD

The Zephyr SDK includes a bundled OpenOCD, but it may not have ESP32 support. To use the Espressif OpenOCD, specify the path when building:

# From the root of the zephyr repository
west build -b <board> samples/hello_world -- -DOPENOCD=/path/to/openocd -DOPENOCD_DEFAULT_PATH=/path/to/openocd/scripts
west debug

References

[1]

https://www.espressif.com/sites/default/files/documentation/esp32_datasheet_en.pdf

[2]

https://www.espressif.com/sites/default/files/documentation/esp32_technical_reference_manual_en.pdf

[3]

https://github.com/espressif/openocd-esp32/releases

[4]

https://github.com/espressif/openocd-esp32/releases/tag/v0.12.0-esp32-20251215

[5]

https://docs.espressif.com/projects/esp-idf/en/latest/esp32/api-guides/jtag-debugging/index.html

[6]

https://soldered.com/product/inkplate-6color/

[7]

https://soldered.com/