DocsTaggerTagger Mainboardv0.4Connectors

Connectors & Pinout

Connector reference for the BattleCore Tagger Mainboard v0.4 — pin assignments, voltages, and intended use for each port.

The Tagger Mainboard v0.4 is built around an ESP32-S3 module, so every logic signal is 3.3 V. Inputs are not 5 V tolerant — never drive a signal pin above 3.3 V. Power is supplied from a battery pack and stepped down on-board to the 5 V and 3.3 V rails.

Each connector below includes a live view of the actual board layout, centred on that port. Use the mouse wheel to zoom out for context (where the connector sits on the whole PCB) or in for detail, and drag to pan. Hover or tap a pad to highlight it in the pin table, and vice-versa.

Power Rails

Rail	Voltage	Source	Used by
`VIN_BATT`	Battery	Battery pack (via external power switch)	Feeds the 5 V buck regulator and battery-level sense.
`PWR_5V`	5 V	PWR_SEL jumper (battery buck or USB VBUS)	System 5 V rail — LEDs, IR emitters, effects, daughterboard.
`PWR_3V3`	3.3 V	On-board 3.3 V buck regulator (from PWR_5V)	ESP32-S3 and all logic / sensor peripherals.
`PWR_GND`	GND · 0 V	—	Common ground reference for the whole board.

Shared SPI Bus

The Display, NFC, LoRa, and Accelerometer ports share one SPI bus — SPI_SCLK, SPI_MOSI, SPI_MISO, and the shared SPI_RST line. Each device is addressed by its own dedicated chip-select (DISPLAY_CS, NFC_CS, LORA_CS, ACELRMTR_CS).

Connectors

Power Connectors
1. Battery Input (BATT_CONNECT)
2. 5 V Source Select (PWR_SEL)
SPI Peripherals
Serial & Daughterboard
I/O & Effects
Infrared
1. IR Emitter Output (IR_OUT)
2. IR Receiver Input (IR_IN)

Power Connectors

Battery Input

BATT_CONNECT

4-pin · 2.5 mm pitch · through-hole · 3 A

Connector: JST XH B4B-XH-A

Main battery input. Connect battery negative to pin 1 and battery positive to pin 4. Pins 2 and 3 are the terminals for an external power switch (e.g. a key switch): pin 3 carries the battery positive (VIN_BATT_IN, shared with pin 4) and pin 2 is the switched rail (VIN_BATT) that feeds the 5 V buck regulator and the battery-level sense divider. Closing the switch between pins 2 and 3 physically connects the battery and powers the board on. Battery voltage must sit above ~5.5 V (e.g. a 2S Li-ion pack) since the on-board regulator is a step-down (buck) converter.

Observe polarity — pin 1 is ground and pin 4 is battery positive. The battery feeds the regulators with no reverse-polarity protection, so connecting the pack backwards can instantly destroy the regulators and downstream electronics. Keep the pack voltage above ~5.5 V (the regulator is a step-down) and within the regulator's rated input voltage.

Location on the PCB (top view). Scroll to zoom, drag to pan; the highlighted port is BATT_CONNECT. Hover or tap a pad to link it to the table. = pin 1

Pin	Signal	Voltage	Notes
1	`PWR_GND`	GND · 0 V	Battery negative / system ground.
2	`VIN_BATT`	Battery	Power-switch terminal — switched rail that feeds the regulators when the switch is closed.
3	`VIN_BATT_IN`	Battery	Power-switch terminal — battery-positive side (shared with pin 4). Bridge to pin 2 via the switch to turn the board on.
4	`VIN_BATT_IN`	Battery	Battery positive input.

5 V Source Select

PWR_SEL

3-pin · 2.54 mm pitch · jumper

Connector: 2.54 mm header (PZ254)

Selects what feeds the board's 5 V system rail (PWR_5V, pin 2 — the common centre pin). Jumper pin 2 to pin 1 to run the board from the battery's 5 V buck regulator, or pin 2 to pin 3 to run it from USB VBUS. The 3.3 V regulator is derived from PWR_5V, so this jumper controls the entire logic supply.

Only ever bridge the centre pin (PWR_5V) to one side. Never link BATT_5V (pin 1) and USB_5V (pin 3) together — that ties the battery's 5 V regulator directly to USB VBUS, back-feeding one source into the other and risking damage to the regulator, the USB host, or the battery circuitry.

Location on the PCB (top view). Scroll to zoom, drag to pan; the highlighted port is PWR_SEL. Hover or tap a pad to link it to the table. = pin 1

Pin	Signal	Voltage	Notes
1	`BATT_5V`	5 V	5 V from the on-board battery buck regulator.
2	`PWR_5V`	5 V	System 5 V rail (common) — feeds the 3.3 V regulator and 5 V peripherals.
3	`USB_5V`	5 V	5 V from USB VBUS, via a 2 A resettable polyfuse.

SPI Peripherals

Display (SPI)

DISPLAY

7-pin · 1.5 mm pitch · SMT

Connector: JST ZH B7B-ZR-SM4-TFT

SPI display port (TFT / OLED). Shares the common SPI bus (SCLK / MOSI / RST) with the other peripherals and uses its own chip-select plus a data/command line.

Location on the PCB (top view). Scroll to zoom, drag to pan; the highlighted port is DISPLAY. Hover or tap a pad to link it to the table. = pin 1

Pin	Signal	Voltage	Notes
1	`PWR_3V3`	3.3 V	Display logic / supply.
2	`PWR_GND`	GND · 0 V	Ground.
3	`SPI_RST`	3.3 V logic	Shared peripheral reset.
4	`SPI_MOSI`	3.3 V logic	Shared SPI data out (controller → display).
5	`SPI_SCLK`	3.3 V logic	Shared SPI clock.
6	`DISPLAY_CS`	3.3 V logic	Dedicated chip-select.
7	`DISPLAY_DC`	3.3 V logic	Data / command select.

Two extra SMT mounting tabs are tied to GND for mechanical retention.

NFC Reader (SPI)

NFC

7-pin · 1.5 mm pitch · SMT

Connector: JST ZH B7B-ZR-SM4-TFT

SPI NFC reader module port. Shares the common SPI bus and uses a dedicated chip-select. Full SPI including MISO so the reader can return tag data.

Location on the PCB (top view). Scroll to zoom, drag to pan; the highlighted port is NFC. Hover or tap a pad to link it to the table. = pin 1

Pin	Signal	Voltage	Notes
1	`PWR_3V3`	3.3 V	Reader supply.
2	`PWR_GND`	GND · 0 V	Ground.
3	`SPI_RST`	3.3 V logic	Shared peripheral reset.
4	`SPI_MOSI`	3.3 V logic	Shared SPI data out.
5	`SPI_SCLK`	3.3 V logic	Shared SPI clock.
6	`SPI_MISO`	3.3 V logic	Shared SPI data in (reader → controller).
7	`NFC_CS`	3.3 V logic	Dedicated chip-select.

Two extra SMT mounting tabs are tied to GND for mechanical retention.

LoRa Radio (SPI)

LORA

8-pin · 1.5 mm pitch · SMT · 1 A

Connector: JST ZH (1.5 mm, 8P)

SPI LoRa radio module port for long-range RF. Shares the common SPI bus with a dedicated chip-select and an extra control line (DIO / busy).

Location on the PCB (top view). Scroll to zoom, drag to pan; the highlighted port is LORA. Hover or tap a pad to link it to the table. = pin 1

Pin	Signal	Voltage	Notes
1	`PWR_3V3`	3.3 V	Radio supply.
2	`PWR_GND`	GND · 0 V	Ground.
3	`SPI_RST`	3.3 V logic	Shared peripheral reset.
4	`SPI_MOSI`	3.3 V logic	Shared SPI data out.
5	`SPI_SCLK`	3.3 V logic	Shared SPI clock.
6	`SPI_MISO`	3.3 V logic	Shared SPI data in.
7	`LORA_CS`	3.3 V logic	Dedicated chip-select.
8	`LORA_DC`	3.3 V logic	Radio control line (DIO / busy / data-command).

Two extra SMT mounting tabs are tied to GND for mechanical retention.

Accelerometer (SPI)

ACELRMTR

6-pin · 1.5 mm pitch · SMT · 2 A

Connector: JST ZH A1501WV-S-6P

SPI accelerometer / motion sensor port. Shares the common SPI bus with its own chip-select for motion sensing.

Location on the PCB (top view). Scroll to zoom, drag to pan; the highlighted port is ACELRMTR. Hover or tap a pad to link it to the table. = pin 1

Pin	Signal	Voltage	Notes
1	`PWR_3V3`	3.3 V	Sensor supply.
2	`PWR_GND`	GND · 0 V	Ground.
3	`SPI_MOSI`	3.3 V logic	Shared SPI data out.
4	`SPI_SCLK`	3.3 V logic	Shared SPI clock.
5	`SPI_MISO`	3.3 V logic	Shared SPI data in.
6	`ACELRMTR_CS`	3.3 V logic	Dedicated chip-select.

Two extra SMT mounting tabs are tied to GND for mechanical retention.

Serial & Daughterboard

GPS Module (UART)

GPS

4-pin · 1.5 mm pitch · SMT · 1 A

Connector: JST ZH (1.5 mm, 4P)

UART GPS receiver port. Provides 3.3 V power and a serial link for position data.

Location on the PCB (top view). Scroll to zoom, drag to pan; the highlighted port is GPS. Hover or tap a pad to link it to the table. = pin 1

Pin	Signal	Voltage	Notes
1	`PWR_3V3`	3.3 V	GPS supply.
2	`PWR_GND`	GND · 0 V	Ground.
3	`GPS_TX`	3.3 V logic	GPS serial out (GPS → controller).
4	`GPS_RX`	3.3 V logic	GPS serial in (controller → GPS).

Two extra SMT mounting tabs are tied to GND for mechanical retention.

Serial Expansion UART

MP_SERIAL

2-pin · 2.54 mm pitch · through-hole

Connector: 2.54 mm header (PZ254)

Spare main-processor UART broken out for a serial device expansion. Currently unused — reserved for attaching a future 3.3 V serial peripheral. 3.3 V logic; do not drive with 5 V levels.

Location on the PCB (top view). Scroll to zoom, drag to pan; the highlighted port is MP_SERIAL. Hover or tap a pad to link it to the table. = pin 1

Pin	Signal	Voltage	Notes
1	`MP_SERIAL_TX`	3.3 V logic	Controller serial out — connect to the device's RX.
2	`MP_SERIAL_RX`	3.3 V logic	Controller serial in — connect to the device's TX.

Daughterboard IO

DBIO

6-pin · 2×3 · 2.54 mm pitch · through-hole

Connector: 2.54 mm header (2×3)

Daughterboard expansion header. Carries both power rails (5 V + 3.3 V), ground, and a UART link to an attached daughterboard (e.g. the audio co-processor).

Location on the PCB (top view). Scroll to zoom, drag to pan; the highlighted port is DBIO. Hover or tap a pad to link it to the table. = pin 1

Pin	Signal	Voltage	Notes
1	`PWR_GND`	GND · 0 V	Ground.
2	`DBIOTX`	3.3 V logic	Controller serial out to daughterboard.
3	`PWR_GND`	GND · 0 V	Ground.
4	`PWR_5V`	5 V	5 V supply to daughterboard.
5	`PWR_3V3`	3.3 V	3.3 V supply to daughterboard.
6	`DBIORX`	3.3 V logic	Controller serial in from daughterboard.

I/O & Effects

Buttons

BUTTONS

5-pin · 1.5 mm pitch · SMT · 1 A

Connector: JST ZH B5B-ZR-SM4-TFT

Trigger and control button inputs. Pin 2 supplies 3.3 V for the harness; each button line is read as a 3.3 V logic input.

Location on the PCB (top view). Scroll to zoom, drag to pan; the highlighted port is BUTTONS. Hover or tap a pad to link it to the table. = pin 1

Pin	Signal	Voltage	Notes
1	`PWR_GND`	GND · 0 V	Ground / common.
2	`PWR_3V3`	3.3 V	3.3 V supply for the button harness.
3	`BUTTON_TRIGGER`	3.3 V logic	Trigger button input.
4	`BUTTON_AUX`	3.3 V logic	Auxiliary button input.
5	`BUTTON_RELOAD`	3.3 V logic	Reload button input.

Two extra SMT mounting tabs are tied to GND for mechanical retention.

Lights (RGB + Muzzle Flash)

LIGHTS

4-pin · 2.5 mm pitch · through-hole · 3 A

Connector: JST XH B4B-XH-A

Output port for addressable RGB lighting and the muzzle-flash effect. The LED string is powered from 5 V; the data and flash lines are 3.3 V logic outputs from the controller.

MUZZLE_FLASH and RGB_DATA come straight from ESP32-S3 GPIOs, which can only safely source a few milliamps. Don't drive a high-power muzzle-flash LED directly from MUZZLE_FLASH — switch it through an external MOSFET powered from the 5 V rail, just like SHOT_EFFECT. RGB_DATA is a 3.3 V data line; 5 V addressable LEDs (e.g. WS2812) may need a level shifter for reliable data. Keep the LED string's total current within the 5 V rail and the connector's 3 A rating.

Location on the PCB (top view). Scroll to zoom, drag to pan; the highlighted port is LIGHTS. Hover or tap a pad to link it to the table. = pin 1

Pin	Signal	Voltage	Notes
1	`PWR_5V`	5 V	5 V supply for the LED string.
2	`PWR_GND`	GND · 0 V	Ground.
3	`MUZZLE_FLASH`	3.3 V logic	Muzzle-flash effect control output — logic-level GPIO; switch a high-power LED through an external MOSFET, don't drive it directly.
4	`RGB_DATA`	3.3 V logic	Addressable RGB (WS2812-style) data out (3.3 V logic).

Shot Effect

SHOT_EFFECT

3-pin · 2.54 mm pitch · through-hole

Connector: 2.54 mm header (PZ254)

Signals a shot / recoil effect device (e.g. solenoid or rumble motor). Powered from 5 V with a single 3.3 V logic control line.

Do not connect a solenoid or rumble motor directly to this connector. SHOT_EFFECT comes straight from an ESP32-S3 GPIO, which can only safely source a few milliamps — a motor or solenoid draws hundreds of milliamps to several amps, far more than the pin can deliver, so wiring one directly will overload and destroy the GPIO (and potentially the MCU). Worse, when an inductive load (motor/solenoid) switches off it produces a high-voltage back-EMF spike that will damage the pin. Always switch the load through an external MOSFET driven by this line, with a flyback diode across the load to clamp that spike.

Location on the PCB (top view). Scroll to zoom, drag to pan; the highlighted port is SHOT_EFFECT. Hover or tap a pad to link it to the table. = pin 1

Pin	Signal	Voltage	Notes
1	`PWR_GND`	GND · 0 V	Ground.
2	`PWR_5V`	5 V	5 V supply for the effect device.
3	`SHOT_EFFECT`	3.3 V logic	Effect control output — gate signal to drive an external MOSFET switching the device.

Infrared

IR Emitter Output

IR_OUT

6-pin · 2×3 · 2.54 mm pitch · through-hole

Connector: 2.54 mm header (2×3)

Drives the IR LED emitter board (the 'shot' transmitter). Provides 5 V power for the emitters and two independent IR control channels. The IR_OUT_x lines are logic-level signals — they don't power the LEDs directly; each one switches an external MOSFET on the emitter board that drives the IR LED from the 5 V rail.

Do not drive the IR LEDs directly from the IR_OUT_x pins. These come straight from ESP32-S3 GPIOs, which can only safely source a few milliamps — the high pulse currents an IR emitter needs are far more than the pin can deliver, so driving an LED directly will overload and destroy the GPIO (and potentially the MCU). Always switch the LED through an external MOSFET driven by the IR_OUT_x line, powering the LED from the 5 V rail.

Location on the PCB (top view). Scroll to zoom, drag to pan; the highlighted port is IR_OUT. Hover or tap a pad to link it to the table. = pin 1

Pin	Signal	Voltage	Notes
1	`PWR_GND`	GND · 0 V	Ground.
2	`PWR_GND`	GND · 0 V	Ground.
3	`PWR_5V`	5 V	5 V supply for the IR emitters.
4	`PWR_5V`	5 V	5 V supply (second contact).
5	`IR_OUT_1`	3.3 V logic	Channel 1 control — logic-level gate signal driving an external MOSFET that switches the IR LED.
6	`IR_OUT_2`	3.3 V logic	Channel 2 control — logic-level gate signal driving an external MOSFET that switches the IR LED.

IR Receiver Input

IR_IN

6-pin · 2×3 · 2.54 mm pitch · through-hole

Connector: 2.54 mm header (2×3)

Input from the IR receiver(s) used to detect incoming shots. Provides 3.3 V power for the receivers and two independent receive channels.

Location on the PCB (top view). Scroll to zoom, drag to pan; the highlighted port is IR_IN. Hover or tap a pad to link it to the table. = pin 1

Pin	Signal	Voltage	Notes
1	`PWR_GND`	GND · 0 V	Ground.
2	`PWR_GND`	GND · 0 V	Ground.
3	`PWR_3V3`	3.3 V	3.3 V supply for the IR receivers.
4	`PWR_3V3`	3.3 V	3.3 V supply (second contact).
5	`IR_RECEIVE_1`	3.3 V logic	IR receiver channel 1 input.
6	`IR_RECEIVE_2`	3.3 V logic	IR receiver channel 2 input.