4 layers34.8 × 35.6 mm
Sw63 mk4 v2
xx0x/sw63
Sci-fi inspired electronic watch. MK4 currently in the development (out in 2026).
70 parts2MIT
4 layers25.6 × 23.6 mm
CANNONBALL
user-will/PCB_CANNONBALL14An ESP32-C3 dev board with more sensors and features then you could know what to do with
- Size
- 25.6 × 23.6 mm
- Copper layers
- 4
- Thickness
- 1.6 mm
- Parts
- 61
- Nets
- 52
- Pads
- 249
- Tracks, vias
- 1,173, 109
- Pours
- 1
- Routed
- Yes
- KiCad
- KiCad 10.0 (file 20260206)
- Created
- 25 Jun 2026
- Updated
- 1 Jul 2026
Overview
CANNONBALL is an open-source printed circuit board by user-will, from the user-will/PCB_CANNONBALL repository on GitHub. It is a 4-layer board of 25.6 × 23.6 mm with 61 parts on 52 nets, routed with 1,173 tracks and 109 vias.
It is built around the ESP32-C3-WROOM-02-H4, VEML6030 and AP2112K-3.3, with the DW01A, LSM6DS3 and USBLC6-4SC6 among its other parts. Its parts include 20 capacitors, 16 resistors, 9 ICs, 4 diodes and 4 connectors. It belongs with the microcontroller boards boards and the ESP32 and RISC-V boards of this library.
Main components
11
ESP32-C3-WROOM-02-H4
SMD,20x18mm-105dBm -40℃~+105℃ 2.4GHz 20.5dBm 345mA 3V~3.6V 82mA Bluetooth5.0 ESP32-C3 On-board PCB Antenna UART、SPI、I2C、I2S、USB SMD,20x18mm WiFi Modules ROHSEspressif SystemsWiFi Modules
VEML6030
SMD-6P,2x2mm-25℃~+85℃ 0.87mm 120klx 16bit 2.5V~3.6V 2mm 2mm I2C Light Intensity Low power/sleep mode、Spectral correction/filtering、Adjustable gain control、Interrupt/event trigger、Built-in temperature compensation SMD-6P,2x2mm Ambient Light Sensors ROHSVishay IntertechnologyAmbient Light Sensors
AP2112K-3.3
SOT253.3V 600mA CMOS Low Dropout Linear Regulator with EnableDiodes IncorporatedUncategorised
DW01A
SOT-23-6L-40℃~+85℃ 1 2.5V 300mV~10V 3uA 4.3V Protection IC Support SOT-23-6L Battery Management ROHSPUOLOPBattery Management
LSM6DS3
LGA-14(2.5x3)-40℃~+85℃ 1.71V~3.6V 8KB Accelerometer Gyroscope SPI、I2C X,Y,Z X,Y,Z ±16g ±2000dps LGA-14(2.5x3) Accelerometers ROHSSTMicroelectronicsAccelerometersUSBLC6-4SC6
SOT-23-6-55℃~+125℃ 0.3pF 15V 300W@8/20us 4.7A@8/20us 5V 6V 80nA ESD Four channels IEC 61000-4-2、IEC 61000-4-5、IEC 61000-4-4 Unidirectional SOT-23-6 ESD and Surge Protection (TVS/ESD) ROHSTECH PUBLICESD And Surge Protection (TVS/ESD)
SK6812-EC20
SMD,2x2mm-40℃~+80℃ 0.65mA 0.65mm 100mcd~200mcd 160mcd~320mcd 160° 1kHz 2000V 2mm 2mm 3.7V~5.5V 460nm~475nm 50mcd~100mcd 520nm~535nm 620nm~630nm 800Kbit/s Built-in power-on reset circuit、Built-in one-way transmission function Semi-transparent lens SMD,2x2mm RGB LEDs(Built-in IC) ROHSOPSCO OptoelectronicsRGB LEDs(Built-In IC)
0805L110/16WR
0805-40℃~+85℃ 1.1A 1.2mm 1.5mm 16V 2.2A 2.3mm 230mΩ 300ms 35mΩ 40A 800mW 0805 Resettable Fuses ROHSLUTEResettable Fuses
2N7002K
SOT-23-55℃~+150℃ 1 N-channel 1.2Ω@10V、1.4Ω@5V 1.6V 2.9pF 300pC@4.5V 30pF 380mA 4.2pF 540mW 60V SOT-23 MOSFETs ROHSDiodes IncorporatedMOSFETsFS8205A
SOT-23-6-55℃~+150℃ 1.2V 1.5W 2 N-Channel 20V 31.5mΩ@2.5V 466pF 5.7nC@4.5V 58pF 65pF 6A SOT-23-6 MOSFETs ROHSTECH PUBLICMOSFETs
MS2A40LWS
SOD-323Schottky DiodesMSKSEMI
README
README.mdREIL INDUSTRIAL - CANNONBALL
A feature-packed ESP32-C3 development board built around the ESP32-C3-WROOM-02-N4, designed to be the last board you need for any project — smart home device, RC car, wearable, or anything else you can dream up.
The big pitch: pull a single-cell LiPo or Li-ion from an old vape, plug it into the JST PH connector, and go. The board handles charging, protection, and fuel gauging — no external circuitry needed.
Features
- MCU — ESP32-C3-WROOM-02-N4 (RISC-V, 2.4 GHz Wi-Fi + BLE, 4 MB flash)
- USB protection — USBLC6-4SC6 TVS diode array on the USB lines
- Battery charging — BQ24075RGT linear charger (100 mA default, 500 mA selectable via GPIO)
- Battery protection — DW01A + FS8205A dual MOSFET pack (over-charge, over-discharge, short circuit)
- Battery monitoring — MAX17048 fuel gauge over I2C with low-battery alert
- 3.3 V regulation — AP2112K-3.3 LDO
- Addressable LEDs — SK6812-EC20 RGB LEDs switched via DMG2301L MOSFET
- IMU — LSM6DS3 (6-axis accelerometer + gyroscope, I2C)
- Temp & humidity — SHT40 (I2C)
- Light sensor — VEML6030 ambient light sensor (I2C)
- I2C expansion — JST SH 1.0 mm 4-pin connector (3.3 V, GND, SDA, SCL)
- Battery connector — JST PH 2.0 mm 2-pin
Power
| Rail | Source | Voltage | Notes |
|---|---|---|---|
| USB-C | External | 5 V nominal, 6 V max | Limited by AP2112K-3.3 LDO max input. Do not exceed 6 V on the 5 V pins or USB input. |
| 5V pin (J5/J6) | External or VBUS | 5 V nominal, 6 V max | Same rail as USB VBUS — feeds the LDO and charger directly. |
| 3V3 pin (J4/J6) | AP2112K-3.3 LDO | 3.3 V exactly | If powering the board externally via the 3V3 pin (bypassing the LDO), supply a regulated 3.3 V. The ESP32 and all peripherals run at 3.3 V with a ±0.3 V tolerance — do not exceed 3.6 V or drop below 3.0 V. |
Pin Reference
| GPIO | Function | Notes |
|---|---|---|
| 3 | MAX17048 alert | Active-low interrupt when battery is low |
| 4 | SK6812 data | Addressable LED data line |
| 5 | LED enable (MOSFET) | Pull high to enable LEDs, low to disable |
| 10 | BQ24075 EN1 (charge rate) | Pull high to increase charge current from 100 mA to 500 mA |
Bill of Materials
| Reference | Part | Function |
|---|---|---|
| U1 | ESP32-C3-WROOM-02-N4 | Main MCU |
| U2 | BQ24075RGT | Li-ion/LiPo battery charger |
| U3 | MAX17048 | Battery fuel gauge (I2C) |
| U4 | DW01A | Battery protection IC |
| U5 | FS8205A | Dual MOSFET for battery protection |
| U6 | AP2112K-3.3 | 3.3 V LDO regulator |
| U7 | USBLC6-4SC6 | USB ESD/TVS protection |
| U8 | LSM6DS3 | 6-axis IMU (I2C) |
| U9 | SHT40 | Temperature & humidity sensor (I2C) |
| U10 | VEML6030 | Ambient light sensor (I2C) |
| Q3 | 2N7002K | N-channel MOSFET (LED power switch) |
| LED1+ | SK6812-EC20 | Addressable RGB LEDs |
Opening in KiCad
- Clone or download this repo
- Open KiCad and select File → Open Project
- Navigate to the repo folder and open
CANNONBALL.kicad_pro
All schematic symbols and footprints are either embedded in the project files or included in the jlcpcb.pretty/ and jlcpcb.kicad_sym local libraries — no additional library setup required.
Battery Compatibility
Any single-cell LiPo or Li-ion (3.6–4.2 V nominal) will work. The onboard protection circuit guards against:
- Over-charge (> 4.2 V)
- Over-discharge (< 2.5 V)
- Short circuit / over-current
Cells salvaged from vapes, old phones, or RC packs all work fine. Use the JST PH 2.0 mm 2-pin connector (positive on pin 1).
Parts
61| Qty | Value | Footprint | References |
|---|---|---|---|
| 10 | 1uF | Capacitor_SMD:C_0603_1608Metric_Pad1.08x0.95mm_HandSolder | C1, C3, C10, C11, C12, C14, C16, C18, C20, C21 |
| 6 | 10K | Resistor_SMD:R_0402_1005Metric_Pad0.72x0.64mm_HandSolder | R2, R3, R7, R8, R14, R15 |
| 4 | 1uF | Capacitor_SMD:C_0402_1005Metric_Pad0.74x0.62mm_HandSolder | C19, C22, C23, C24 |
| 3 | 100R | Resistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolder | R10, R12, R13 |
| 3 | 10uF | Capacitor_SMD:C_0603_1608Metric_Pad1.08x0.95mm_HandSolder | C8, C9, C17 |
| 3 | 5.1k | Resistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolder | R4, R5, R11 |
| 3 | LOGO | LOGO | G***, G***, G*** |
| 2 | 10K | Resistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolder | R6, R18 |
| 2 | 4.7uF | Capacitor_SMD:C_0603_1608Metric_Pad1.08x0.95mm_HandSolder | C6, C15 |
| 2 | SK6812-EC20 | leds:LED-SMD_4P-L2.0-W2.0-BR | LED1, LED2 |
| 1 | 0805L110/16WR | power:F0805 | F2 |
| 1 | 1.8K | Resistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolder | R16 |
| 1 | 10uF | Capacitor_SMD:C_0402_1005Metric_Pad0.74x0.62mm_HandSolder | C13 |
| 1 | 2K | Resistor_SMD:R_0603_1608Metric_Pad0.98x0.95mm_HandSolder | R17 |
| 1 | 2N7002K | Package_TO_SOT_SMD:SOT-23 | Q3 |
| 1 | AP2112K-3.3 | PCM_SparkFun-Semiconductor-Standard:SOT23-5 | U2 |
| 1 | DW01A | Package_TO_SOT_SMD:SOT-23-6 | U5 |
| 1 | ESP32-C3-WROOM-02 | RF_Module:ESP32-C3-WROOM-02 | U3 |
| 1 | FS8205A | power:SOT-23-6_L2.9-W1.6-P0.95-LS2.8-BR | Q1 |
| 1 | I2C_CONN | connectors:CONN-SMD_4P-P1.00_ZX-SH1.0-4PLN | J4 |
| 1 | JST-PH 2.0 BATTERY | connectors:CONN-TH_2P-P2.00_XUNPU_WAFER-PH2.0-2PLB | J3 |
| 1 | LED | LED_SMD:LED_0603_1608Metric_Pad1.05x0.95mm_HandSolder | D4 |
| 1 | LEFT_PINS | PCM_fab:PinHeader_01x07_P2.54mm_Vertical_THT_D1mm | J5 |
| 1 | LSM6DS3 | Package_LGA:LGA-14_2x2mm_P0.35mm_LayoutBorder3x4y | U4 |
| 1 | MAX17048 | PCM_SparkFun-Semiconductor-Standard:DFN-8_2x2mm_P0.5mm_EP1.2x0.8mm | U10 |
| 1 | MS2A40LWS | diode:SOD-323_L1.7-W1.25-LS2.5-RD | D2 |
| 1 | RIGHT_PINS | PCM_fab:PinHeader_01x07_P2.54mm_Vertical_THT_D1mm | J6 |
| 1 | SHT40 | PCM_SparkFun-Sensor:Sensirion_DFN-4_1.5x1.5mm_P0.8mm_SHT4x_NoCentralPad | U7 |
| 1 | SW_Push | switches:KEY-SMD_L4.0-W3.0-LS4.9-1 | SW1 |
| 1 | TI BQ24075RGTR | Package_DFN_QFN:VQFN-16-1EP_3x3mm_P0.5mm_EP1.6x1.6mm | U6 |
| 1 | TYPE-C 16PIN 2MD | connectors:USB-C-SMD_TYPE-C-16PIN-2MD-073 | USB1 |
| 1 | USBLC6-4SC6 | Package_TO_SOT_SMD:SOT-23-6 | U1 |
| 1 | VEML6030 | sensors:SENSORS-SMD_VEML6030 | U8 |
Questions
How big is the CANNONBALL PCB?
It measures 25.6 × 23.6 mm and has 4 copper layers, 1.6 mm thick.
What parts does the CANNONBALL use?
61 parts, built around the ESP32-C3-WROOM-02-H4, VEML6030, AP2112K-3.3 and DW01A. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.
Where can I download the CANNONBALL KiCad files?
From the user-will/PCB_CANNONBALL repository on GitHub, at the commit this page was made from: the board is CANNONBALL.kicad_pcb and its schematic CANNONBALL.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the CANNONBALL design in my own project?
Its repository states no licence, so its author keeps all rights: ask user-will before reusing the design.
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