By name: m5stickc-plus-expert description: > Expert for programming and using the M5Stack M5StickC PLUS and M5StickC PLUS2 — the stick-shaped ESP32-PICO mini IoT dev kit with a 1.14" TFT, 6-axis IMU (MPU6886), IR transmitter, microphone, RTC, buzzer, buttons, and Grove port. Use when the user wants to: program/flash the StickC PLUS or PLUS2 (Arduino IDE, PlatformIO, UIFlow2, or MicroPython); find a GPIO/pinout or peripheral address; read the IMU/buttons/mic, drive the display, send IR, play tones, use the RTC, or read battery/power; connect HATs or Grove Units; get the PLUS-vs-PLUS2 differences (AXP192 vs GPIO4 HOLD pin, pin remaps); wear it as a watch; or pick and build a project. Triggers: "M5StickC", "StickC Plus", "M5StickC PLUS2", "M5Stack stick", "ESP32-PICO", "M5Unified", "UIFlow", "MPU6886", "flash my stick", "stick pinout", "IR remote with the stick", "M5 watch". tools: Read
M5StickC PLUS / PLUS2 Expert
The M5StickC PLUS and M5StickC PLUS2 are pocket ESP32 dev kits in a ~48×24×14 mm stick. Onboard: 1.14" 135×240 TFT (ST7789v2), 6-axis IMU (MPU6886), IR LED, PDM mic (SPM1423), RTC (BM8563), passive buzzer, 2 buttons + power/wake, red LED, USB-C, and a Grove (I2C/UART/GPIO) port. They stack HATs (top header) and chain Grove Units, and can be worn as a watch with the Watch HAT.
Know which variant you have — it changes the pins and power code. PLUS uses an AXP192 PMU; PLUS2 removes it and uses a GPIO4 HOLD pin you must drive HIGH to stay powered. Several GPIOs differ. See
references/hardware.mdbefore wiring or porting code.
How to Use This Skill
Progressive disclosure — load only what the task needs:
| Task | Load |
|---|---|
| Pinout / GPIO map, peripheral I2C addresses, specs, PLUS-vs-PLUS2 differences, HATs & Grove Units, power/battery, wearing it as a watch | references/hardware.md |
| Program in C++ (Arduino IDE or PlatformIO): M5Unified API, display/IMU/buttons/buzzer/IR/RTC/mic/WiFi/power, example sketches, upload settings, USB drivers | references/arduino.md |
| Program visually or in Python: UIFlow2 blockly, MicroPython, flashing firmware with M5Burner | references/uiflow-micropython.md |
| Project ideas with build notes (IR universal remote, gesture wand, Wi-Fi sensor dashboard, BLE HID, clock/timer, sound meter, games, Claude Desktop Buddy, …) | references/projects.md |
Quick Start (Arduino + M5Unified — works on both variants)
M5Unified auto-detects the board, so it's the recommended library for new projects (handles the
PLUS/PLUS2 differences for you). Install M5Unified (pulls in M5GFX) via Library Manager,
select board "M5StickC Plus" or "M5StickC Plus2", and upload.
#include <M5Unified.h>
void setup() {
auto cfg = M5.config();
M5.begin(cfg); // inits display, IMU, buttons, power, etc.
M5.Display.setRotation(3); // landscape
M5.Display.setTextSize(2);
M5.Display.println("Hello M5!");
}
void loop() {
M5.update(); // refresh buttons / sensors every loop
if (M5.BtnA.wasPressed()) { // BtnA = big front button (G37)
M5.Speaker.tone(4000, 100); // passive buzzer
M5.Display.println("A!");
}
}
Upload baud: try 1500000; drop to 115200 if uploads fail. Details + PlatformIO config: references/arduino.md.
API Cheat Sheet (M5Unified)
| Need | Call |
|---|---|
| Init / per-loop refresh | M5.begin(M5.config()) · M5.update() |
| Screen (M5GFX) | M5.Display.print/fillScreen/drawString/setRotation/setBrightness |
| Buttons | M5.BtnA / M5.BtnB → .wasPressed() .isPressed() .wasReleased() |
| IMU (MPU6886) | M5.Imu.update() then M5.Imu.getImuData() → .accel.x .gyro.y |
| Buzzer | M5.Speaker.tone(freqHz, ms) |
| Battery / power | M5.Power.getBatteryLevel() · M5.Power.powerOff() |
| RTC (BM8563) | M5.Rtc.getDateTime() / setDateTime() |
| Mic (PDM) | M5.Mic.begin() · M5.Mic.record(buf, len, rate) |
IR send needs IRremoteESP8266 (IR LED on G9 PLUS / G19 PLUS2). Wi-Fi/BLE use the stock ESP32 WiFi.h / BLEDevice.h.
Gotchas
- PLUS2 powers off if GPIO4 (HOLD) goes LOW. On PLUS2, set the hold pin HIGH early (M5Unified does this in
M5.begin); custom/bare code that doesn't will shut off the moment USB is unplugged. - No AXP192 on PLUS2. Code that calls AXP192 (screen brightness, battery voltage, power off) from the old
M5StickCPluslibrary won't work on PLUS2 — useM5Unified(M5.Power,M5.Display.setBrightness) for portability. - Pin remaps between variants: IR/LED, DC, RST, battery-sense, and the wake button all moved. Never reuse raw GPIO numbers across PLUS and PLUS2 — check
references/hardware.md. - Buttons: BtnA = front "M5" button (G37), BtnB = side button (G39). The power button is separate (PLUS: via AXP192; PLUS2: 6 s press / G35 wake).
- The buzzer is passive — you must drive a frequency (
tone), not just set a pin HIGH. - No serial port? Install the USB-serial driver (PLUS2 = CH9102; some sticks = CP210x/FTDI) and use a data USB-C cable, not charge-only.
- Library choice: prefer M5Unified + M5GFX. The legacy
M5StickCPlus/M5StickCPlus2libraries are device-specific and don't port between variants. - Pin G0 / G36 / G25-26 are exposed but shared (G0 = mic clock / boot strap; G36/G25/G26 on the header) — mind conflicts when adding HATs.
Related
- To build the BLE Claude Desktop Buddy desk pet on this hardware, use the existing
claude-desktop-buddyskill (it covers the firmware + Nordic-UART protocol). This skill covers the device generally; that one covers that specific project.