m5stack ESP32-C5HF4 M5StampC5 Module

AI context

Dense context for pasting into a model prompt — addresses, pinout, voltages, tolerances and the vendor's reference circuit.

PART: M5Stack Stamp-C5, SKU S016, a 17.6 x 19.1 x 3.4 mm (1.8 g) embedded wireless module built on the Espressif ESP32-C5HF4 - RISC-V 32-bit single-core at up to 240 MHz, 384 KB SRAM, 4 MB flash - with 2.4 and 5 GHz dual-band Wi-Fi 6, BLE 5 and IEEE 802.15.4 (Zigbee/Thread) on one shared antenna through an LFD182G45DCHD481 dual-band diplexer. The board adds a USB Type-C port, a 3.7 V Li-ion battery input with an SGM40567-4.2XG/TR charger (charge current approx. 200 mA), a TPS2116DRLR power mux between USB and battery, a JW5712 buck regulator, an IPEX-1 antenna connector, a 12-pin 0.5 mm rear FPC expansion port and two status LEDs (RED = charging, BLUE = G28/BOOT).
ADDRESSES: none. There is no I2C device on the board and M5Stack publishes no fixed bus address for it, so a scan of the pads shows nothing at any address.
PINOUT: the only connector M5Stack numbers is the 0.5 mm-12P rear FPC (schematic JP3), pins 1-12 in the vendor's own order: 1 = 3V3, 2 = 3V3, 3 = G23, 4 = G0, 5 = G24, 6 = G25, 7 = GND, 8 = G26, 9 = G27, 10 = TXD(G11), 11 = GND, 12 = RXD(G12). The 2.54 mm edge pads are the schematic's JP1 and JP2 (7 pads each) and are named only, never numbered: the pad GPIO total is 11 (G1, G2, G3, G4, G5, G6, G7, G8, G9, G10, G28), the other three being 3.3 V, GND and the battery/USB input; G28 doubles as the BOOT/download strap. Combined with the FPC the module exposes 19 GPIO.
SUPPLY: 5 V over USB Type-C, DC 3.7 V from a Li-ion cell, or 3.3 V into the 3V3 pads (the FPC carries 3V3 on pins 1 and 2). The datasheet's absolute maximum for the ESP32-C5 input power pins is -0.3 to 3.6 V; recommended VDD range is 3.0-3.3-3.6 V and cumulative input current 0.6 A minimum. M5Stack rates the on-board JW5712 buck at 600 mA maximum output. Deep sleep on battery measures 3.7 V at 13 uA; the vendor publishes no active-current figure for the module.
LOGIC: 3.3 V I/O on every GPIO. The 3V3 pads are the buck's regulated output, not a 5 V logic level, and the TXD/RXD pads on FPC 10 and 12 are 3.3 V UART0-level signals driven through R5 (499 ohm). Exceeding 3.6 V on any 3V3-referenced pin puts the module above the ESP32-C5's absolute maximum input voltage and can permanently damage the chip.
REFERENCE CIRCUIT: the vendor's schematic is the source for the fitted parts - crystal X1 (TJ1148000HYFBC) loaded with C6 10 pF and C7 12 pF; C19 1 uF and C29 100 nF decoupling at the ESP32-C5; R4 and R6 10 kOhm; the buck's L1 2.2 uH with C2 10 uF and C4 1 uF, R7 and R8 10 kOhm, VSEL1/VSEL2/VSEL3 tied so the output is 3.3 V; USB Type-C CC resistors R2 and R3 at 5.1 kOhm; common-mode filter FT1 and ESD arrays DR1/DR2 (H5VN06B) on the USB pair; C1 1 uF and C5 1 uF on VBUS/USB_IN; the charger's R9 10 kOhm and C11 1 uF with C28 1 uF on VBAT; LED resistors R1 and R10 at 1 kOhm. No pull-up resistor is fitted on any GPIO, so an external I2C bus on the pads needs its own pair.
TRAPS: (1) M5Stack warns that the FPC cable's pin order must be checked before connecting, otherwise the hardware can be burned out. (2) When the load on the 3.3 V output from the pads or FPC reaches 300 mA or more, a 100 uF or larger capacitor must be added in parallel at the output to hold the rail. (3) Download mode is entered by tying G28 to GND and then powering the module - G28 is also the blue LED's pin. (4) The 2.54 mm pad rows carry no printed pin numbers, so any 1-N sequence quoted for them is not silkscreen. (5) SKU S016-DIP is this same PCB with the FPC connector pre-soldered and two 2.54-7P headers supplied, not a different board.