# M5Stack CoreInk: specs and pinout

> M5Stack CoreInk (K048): an ESP32-PICO-D4 controller with a 1.54 inch 200x200 black and white E-Ink display, buttons, buzzer and a built-in battery.

[HTML version](https://soldr.ai/docs/boards/m5stack-coreink)

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M5Stack CoreInk (K048): an ESP32-PICO-D4 controller with a 1.54 inch 200x200 black and white E-Ink display, buttons, buzzer and a built-in battery.

Every value cites its sourceOfficial pinout

[Buy on Compoden](https://compoden.com/products/m5stack-coreink-esp32-e-ink-display-development-board)

## Specs

| Spec | Value | Source |
|---|---|---|
| SoC | ESP32-PICO-D4, Xtensa 32-bit LX6 dual-core, up to 240 MHz | source p.4, Specifications |
| Memory | 520 KB SRAM, 4 MB flash | source p.4, Specifications |
| Wi-Fi | 2.4 GHz Wi-Fi | source p.4, Specifications |
| Input voltage | 5 V at 500 mA (USB Type-C) | source p.4, Specifications |
| Display | 1.54 inch E-Ink, 200 x 200, 1-bit black and white, SPI (GDEY0154D67) | source p.4, Specifications |
| RTC | BM8563 (I2C, SDA G21, SCL G22) | source p.4, Specifications; p.7, PinMap |
| Battery | 390 mAh at 3.7 V (built-in) | source p.4, Specifications |
| Expansion header | HY2.0-4P (GND, 5V, G32, G33) | source p.7, PinMap |
| Operating temperature | 0 to 60 C | source p.4, Specifications (Operating Temperature) |
| E-Ink refresh time | 2 s full refresh, 0.26 s partial refresh; recommended refresh interval 15 s | source p.4, Specifications (E-Ink Display); p.2 Notes |
| Buttons, LED, buzzer | Programmable button, reset, power; green LED; passive buzzer | source p.4, Specifications |

## Power

| | Value | Source |
|---|---|---|
| Supply | 5 V at 500 mA via USB Type-C; built-in 390 mAh battery | source p.4, Specifications |

## Pinout

The HY2.0-4P port is the board's own expansion connector (PORT.CUSTOM); the product document gives its pin functions as GND, 5V, G32 and G33.

| Pin | Function | Voltage | Notes | Source |
|---|---|---|---|---|
| G4 | E-Ink BUSY | | E-Ink display GDEY0154D67, SPI | source p.6, PinMap |
| G0 | E-Ink RST | | | source p.6, PinMap |
| G15 | E-Ink D/C | | | source p.6, PinMap |
| G9 | E-Ink CS | | | source p.6, PinMap |
| G18 | E-Ink SCK | | | source p.6, PinMap |
| G23 | E-Ink MOSI | | | source p.6, PinMap |
| G37 | Dial switch up | | | source p.6, PinMap |
| G38 | Dial middle (press) | | | source p.6, PinMap |
| G39 | Dial switch down | | | source p.6, PinMap |
| G5 | User button | | | source p.6, PinMap |
| G10 | LED | | green LED | source p.6, PinMap |
| G2 | Buzzer | | passive buzzer | source p.6, PinMap |
| G12 | Power control (HOLD) | | | source p.6, PinMap |
| G21 | RTC SDA (BM8563) | | | source p.7, PinMap |
| G22 | RTC SCL (BM8563) | | | source p.7, PinMap |
| G1 | USB to TTL RXD (CP2104) | | | source p.7, PinMap |
| G3 | USB to TTL TXD (CP2104) | | | source p.7, PinMap |
| G32 | HY2.0-4P PORT.CUSTOM (signal) | | HY2.0-4P: black GND, red 5V, yellow G32, white G33 | source p.7, PinMap |
| G33 | HY2.0-4P PORT.CUSTOM (signal) | | | source p.7, PinMap |
| HY2.0-4P | Port pins: black GND, red 5V, yellow G32, white G33 | | Also a 5 V pin; ESP32 logic is 3.3 V so signal pins are 3.3 V only | source p.7, PinMap (HY2.0-4P) |

## Build with it
Project ideas for the M5Stack CoreInk. Each link opens Soldr with the prompt filled in; Soldr assigns the pins, checks power and shows how to wire every part.

- [A desk note board that shows a short text message on the screen of an M5Stack CoreInk](https://app.soldr.ai/?prompt=I%20want%20to%20build%20a%20desk%20note%20board%20that%20shows%20a%20short%20text%20message%20on%20the%20screen%20of%20an%20M5Stack%20CoreInk): The 200 x 200 e-ink screen keeps the image with no power, and the full refresh takes about 2 s; update it from a phone over Wi-Fi. Keep refreshes to about one every 15 s or slower as M5Stack advises.
- [An e-ink to-do list that I edit with the dial switch on an M5Stack CoreInk](https://app.soldr.ai/?prompt=I%20want%20to%20build%20an%20e-ink%20to-do%20list%20that%20I%20edit%20with%20the%20dial%20switch%20on%20an%20M5Stack%20CoreInk): The dial switch (up G37, press G38, down G39) and user button G5 give four inputs, enough to scroll and tick items on the e-ink screen.
- [An e-ink countdown timer that wakes on schedule with an M5Stack CoreInk](https://app.soldr.ai/?prompt=I%20want%20to%20build%20an%20e-ink%20countdown%20timer%20that%20wakes%20on%20schedule%20with%20an%20M5Stack%20CoreInk): The BM8563 RTC on G21 and G22 wakes the board for a refresh and the buzzer on G2 signals the end, so the battery lasts between updates.
- [A weekly habit tracker on an M5Stack CoreInk using the dial switch and e-ink screen](https://app.soldr.ai/?prompt=I%20want%20to%20build%20a%20weekly%20habit%20tracker%20on%20an%20M5Stack%20CoreInk%20using%20the%20dial%20switch%20and%20e-ink%20screen): The e-ink screen holds the grid without power, the dial marks a day done, and the RTC keeps the date between wake-ups.

## Common mistakes

- Refreshing the E-Ink screen at a high frequency for a long time: the product note says to avoid long-term high-frequency refresh and quotes the recommended refresh interval as "(15s / time)". (source: [link](https://m5stack.oss-cn-shenzhen.aliyuncs.com/resource/docs/static/pdf/static/en/core/CoreInk.pdf), Notes, p.2)
- Leaving the screen in strong ultraviolet light for long periods: the note says this can cause irreversible damage to the E-Ink screen. (source: [link](https://m5stack.oss-cn-shenzhen.aliyuncs.com/resource/docs/static/pdf/static/en/core/CoreInk.pdf), Notes, p.2)

## Not covered by the official source

- The PinMap voltage column is not stated in the product document; GPIO voltage fields are not given.
- The GDEY0154D67 display datasheet and the ESP32-PICO-D4 datasheet are not given on this page; the CoreInk page lists them as links.
- The HY2.0-4P port exposes G32, G33 and 5 V; whether 5 V is output or input is not stated in the product document, so no external parts are used in the ideas.
- Pin voltages from the schematic are not included; GPIO voltage fields are not given.

## Sources

- [link](https://m5stack.oss-cn-shenzhen.aliyuncs.com/resource/docs/static/pdf/static/en/core/CoreInk.pdf) (M5Stack CoreInk K048 product document, update time 2026-11-05, 8 pp)
- [link](https://m5stack.oss-cn-shenzhen.aliyuncs.com/resource/docs/schematic/Core/coreink/coreink_sch.pdf) (CoreInk schematic, 1 p.)