2 layers30.5 × 20.3 mm
4 layers26 × 26 mm
OpenTag
Cuprum77/OpenTagOpen source Bluetooth location finding beacons
- Size
- 26 × 26 mm
- Copper layers
- 4
- Thickness
- 0.8 mm
- Parts
- 47
- Nets
- 40
- Pads
- 180
- Tracks, vias
- 268, 55
- Pours
- 26
- Routed
- Yes
- KiCad
- KiCad 8.0 (file 20240108)
- Created
- 26 Nov 2024
- Updated
- 12 Sep 2026
Overview
OpenTag is an open-source printed circuit board by Cuprum77, from the Cuprum77/OpenTag repository on GitHub. It is a 4-layer board of 26 × 26 mm with 47 parts on 40 nets, routed with 268 tracks and 55 vias.
It is built around the STM32WB30CEU5A, MLPF-WB55-01E3 and BMA400, with the CR2032 among its other parts. Its parts include 29 capacitors, 5 resistors, 2 ICs, 2 diodes and 2 crystals. It belongs with the STM32 boards of this library.
Main components
4
STM32WB30CEU5A
UFQFPN-48(7x7)-100dBm -10℃~+85℃ 1Mbps 2.4GHz 2V~3.6V 4dBm 7.9mA 8.8mA SPI、USART、I2C ZigBee、Bluetooth、802.15.4 transceiver UFQFPN-48(7x7) Microcontrollers (MCU/MPU/SOC) ROHSSTMicroelectronicsMicrocontrollers (MCU/MPU/SOC)
MLPF-WB55-01E3
SMD-6P,1.6x1mm-40℃~+105℃ 1.1dB 2.4GHz~2.5GHz 50Ω Low Pass SMD-6P,1.6x1mm RF Filters ROHSSTMicroelectronicsRF Filters
BMA400
LGA-12(2x2)-40℃~+85℃ 1.71V~3.6V 12bit 160nA 1KB Accelerometer SPI、I2C X,Y,Z ±16g LGA-12(2x2) Accelerometers ROHSBosch SensortecAccelerometers
CR2032
-- Unclassified goods ROHSMaxellUncategorised
README
hardware/README.mdHardware
Parts
47| Qty | Value | Footprint | References |
|---|---|---|---|
| 14 | 22u | AirTag:C_0805_2012Metric | C1, C2, C4, C5, C7, C9, C10, C11, C12, C17, C18, C19, C20, C21 |
| 11 | 100n | AirTag:C_0402_1005Metric | C3, C6, C8, C22, C23, C24, C25, C26, C27, C28, C29 |
| 4 | 2k2 | AirTag:R_0402_1005Metric | R2, R3, R4, R5 |
| 4 | 6p | AirTag:C_0402_1005Metric | C13, C14, C15, C16 |
| 2 | Bridge | Jumper:SolderJumper-2_P1.3mm_Open_RoundedPad1.0x1.5mm | JP1, JP2 |
| 1 | 10k | AirTag:R_0402_1005Metric | R1 |
| 1 | 2.4GHz Antenna | RF_Antenna:Texas_SWRA117D_2.4GHz_Right | AE1 |
| 1 | 32.768kHz | Crystal:Crystal_SMD_3215-2Pin_3.2x1.5mm | Y2 |
| 1 | 32MHz | Crystal:Crystal_SMD_2016-4Pin_2.0x1.6mm | Y1 |
| 1 | BMA400 | AirTag:LGA-12 | U1 |
| 1 | CR2032 | AirTag:BAT-HLD-001 | BT1 |
| 1 | LED Derg | AirTag:LED_0805_2012Metric | D1 |
| 1 | LED Pink | AirTag:LED_0805_2012Metric | D2 |
| 1 | LOGO | LOGO | G*** |
| 1 | MLPF-WB55-01E3 | AirTag:ST-Bumpless-CSP-6 | F1 |
| 1 | PawPad | AirTag:Paw-Connect_RevB_TC2030-IDC-NL_2x03_P1.27mm_Vertical | PAW1 |
| 1 | STM32WB30CEU5A | Package_DFN_QFN:QFN-48-1EP_7x7mm_P0.5mm_EP5.45x5.45mm | U2 |
Questions
How big is the OpenTag PCB?
It measures 26 × 26 mm and has 4 copper layers, 0.8 mm thick.
What parts does the OpenTag use?
47 parts, built around the STM32WB30CEU5A, MLPF-WB55-01E3, BMA400 and CR2032. 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 OpenTag KiCad files?
From the Cuprum77/OpenTag repository on GitHub, at the commit this page was made from: the board is hardware/OpenTag.kicad_pcb and its schematic hardware/OpenTag.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the OpenTag design in my own project?
Its repository states no licence, so its author keeps all rights: ask Cuprum77 before reusing the design.
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