M5stack Cardputer Adv

M5Stack Cardputer Adv development

The Cardputer Adv is an ESP32-S3-based pocket computer from M5Stack: a 56-key keyboard, 1.14" IPS screen, IMU, mic/speaker, Grove and EXT expansion ports, microSD, and a 1750mAh battery, all in an 84 x 54 x 19.6mm shell. Official docs: https://docs.m5stack.com/en/core/Cardputer-Adv

Use this skill to write correct firmware for it (Arduino, PlatformIO, ESP-IDF, or UIFlow2/MicroPython), to explain what a pin or peripheral does, or to debug hardware-facing code (wrong I2C address, keyboard not responding, display not initializing, etc).

Important: this is not the original Cardputer

M5Stack sells two boards with very similar names and the same enclosure shape. Don't assume code for one works unmodified on the other.

If the user's code touches raw GPIO pin numbers for the keyboard or mic, double-check which board it targets — a sketch written for the original Cardputer's GPIO matrix keyboard will not read keys correctly on the Adv, which exposes its keyboard only through the TCA8418 over I2C.

The good news: if you use the official M5Cardputer Arduino library (which wraps M5Unified/M5GFX), the same high-level API (M5Cardputer.Keyboard, .Display, .Speaker, .Mic, .Imu) works on both boards — the library detects which hardware is present and talks to the right chip underneath. Prefer that library over hand-rolled register access unless the user is specifically doing bare-metal ESP-IDF work or needs something the library doesn't expose.

Quick specs

• SoC: ESP32-S3FN8, dual-core Xtensa LX7 @ 240MHz, 8MB flash
• Display: 1.14", 240x135px, ST7789V2 driver, SPI
• Keyboard: 56 keys (4 rows x 14 cols), TCA8418 I2C controller, 160gf keypress
• IMU: BMI270, 6-axis, I2C
• Audio: ES8311 codec, MEMS mic (65dB SNR), NS4150B amp + 8Ω/1W speaker, 3.5mm jack
• Storage: microSD slot
• Expansion: Grove port (HY2.0-4P), EXT 2.54-14P header (SPI/I2C/UART)
• Connectivity: WiFi + BLE (integrated in ESP32-S3)
• Battery: 1750mAh Li-po; ~120-155mA active draw depending on radio use; 0.23µA standby (power switch off)
• Other: IR emitter, magnetic back, LEGO-compatible mounting holes, lanyard hole
• Size / weight: 84.0 x 54.0 x 19.6mm, 81.0g

Full pin-by-pin map (display, keyboard/IMU I2C, audio, SD, Grove, EXT, IR, battery ADC) is in references/pinout.md — read it whenever you need an exact GPIO number rather than re-deriving it.

Picking a development platform

The board officially supports four workflows. Ask the user which one they're using if it's not obvious from their code or request; default to Arduino/C++ with the M5Cardputer library if they don't have a preference, since that's the most common path and has the broadest example coverage.

Read the relevant reference file before writing code for that platform — each one has the actual include/init pattern and the gotchas specific to that toolchain, rather than generic advice.

Compatible caps

Caps snap onto the 14-pin EXT header. When a user mentions one by name, point them at the dedicated skill for register-level detail and pin mapping — the EXT header carries SPI/I2C/UART, so multiple caps reuse the same physical pins for different purposes and mis-mapping is easy.

Note: the LoRa cap's SPI bus shares MOSI/MISO/CLK with the microSD slot (G14/G39/G40) — separate CS pins (G5 vs G12), so both can coexist on one SPIClass, but two independently configured buses to the same pins will fight. The cap skill covers this in detail.

Official resources

• Docs page: https://docs.m5stack.com/en/core/Cardputer-Adv
• Arduino library: https://github.com/m5stack/M5Cardputer (supports both Cardputer and Cardputer Adv)
• ESP-IDF factory firmware (reference implementation): https://github.com/m5stack/M5Cardputer-UserDemo/tree/CardputerADV
• Schematic (PDF): https://m5stack-doc.oss-cn-shenzhen.aliyuncs.com/1178/Sch_M5CardputerAdv_v1.0_2025_06_20_17_19_58.pdf
• 3D model / mechanical drawing (PDF): https://m5stack-doc.oss-cn-shenzhen.aliyuncs.com/1178/K132-Adv-cardputer-ADV.pdf
• Structure files: https://github.com/m5stack/M5_Hardware/tree/master/Products/K132-Adv_Cardputer-Adv/Structures

Working with the user

• If they paste an error, check whether it's an I2C problem first (wrong address, bus not initialized, or M5Cardputer.begin() missing/misordered) — most Cardputer Adv bring-up issues on this board are I2C-related because keyboard, IMU, and audio codec all share one bus (SDA=G8, SCL=G9).
• If they ask "why doesn't my keyboard code from my old Cardputer work", point them at the table above — it's almost always the GPIO-matrix vs TCA8418 difference.
• Library APIs move; treat the code patterns in the reference files as representative of the current M5Unified/M5Cardputer API shape, but if the user hits a compile error on a specific method name, check https://github.com/m5stack/M5Cardputer for the current signature rather than assuming the reference file is exactly up to date.