2 layers23.2 × 52.4 mm
4 layers17 × 22.1 mm
Firefly
sjacksonhodum/fireflypico balloon pcb
- Size
- 17 × 22.1 mm
- Copper layers
- 4
- Thickness
- 1.6 mm
- Parts
- 39
- Nets
- 52
- Pads
- 145
- Tracks, vias
- 305, 24
- Pours
- 1
- Routed
- Yes
- KiCad
- KiCad 10.0 (file 20260206)
- Created
- 18 Apr 2026
- Updated
- 29 Apr 2026
Overview
Firefly is an open-source printed circuit board by sjacksonhodum, from the sjacksonhodum/firefly repository on GitHub. It is a 4-layer board of 17 × 22.1 mm with 39 parts on 52 nets, routed with 305 tracks and 24 vias.
It is built around the ATMEGA328P-AU, DMP2305U and MAX-M10S, with the ASTX-H11-25.000MHZ-T, BAT20JFILM and SI5351A-B-GT among its other parts. Its parts include 14 capacitors, 7 resistors, 6 connectors, 4 ICs and 3 inductors. It belongs with the AVR (ATmega, ATtiny) boards of this library.
Main components
6
ATMEGA328P-AU
TQFP-32(7x7)-40℃~+85℃ 1.8V~5.5V 10bit 1KB 20MHz 23 2KB 32KB 8 Bit AVR Built-in FLASH TQFP-32(7x7) Microcontrollers (MCU/MPU/SOC) ROHSMicrochip TechnologyMicrocontrollers (MCU/MPU/SOC)
DMP2305U
SOT-23-55℃~+150℃ 1 P-Channel 1.4W 20V 4.2A 60mΩ@4.5V 64pF 69pF 7.6nC@4.5V 727pF 900mV SOT-23 MOSFETs ROHSDiodes IncorporatedMOSFETs
MAX-M10S
LCC-18_10.1X9.7LCC-18_10.1X9.7 New Arrivals ROHSu-bloxUncategorised
ASTX-H11-25.000MHZ-T
SMD3225-4P-30℃~+75℃ 25MHz 3.3V 5.5mA HCMOS ±2.5ppm SMD3225-4P Temperature Compensated Crystal Oscillators (TCXO) ROHSAbraconTemperature Compensated Crystal Oscillators (TCXO)
BAT20JFILM
SOD-3231 Independent 12uA@15V 1A 23V 5A 620mV@1A SOD-323 Schottky Diodes ROHSSTMicroelectronicsSchottky Diodes
SI5351A-B-GT
MSOP-10-40℃~+85℃ 1.71V~3.6V 200MHz 3 I2C MSOP-10 Clock Generators, PLLs, Frequency Synthesizers ROHSSilicon LabsClock Generators, PLLs, Frequency Synthesizers
Parts
39| Qty | Value | Footprint | References |
|---|---|---|---|
| 3 | 120pF | Capacitor_SMD:C_0402_1005Metric | C10, C12, C14 |
| 3 | 1K | Resistor_SMD:R_0402_1005Metric | R1, R3, R4 |
| 3 | 390nH | Inductor_SMD:L_0402_1005Metric | L1, L4, L5 |
| 3 | 4.7K | Resistor_SMD:R_0402_1005Metric | R2, R5, R6 |
| 2 | 0.47uF | Capacitor_SMD:C_0402_1005Metric | C3, C6 |
| 2 | 1.0uF | Capacitor_SMD:C_0402_1005Metric | C1, C2 |
| 2 | 10nF | Capacitor_SMD:C_0402_1005Metric | C4, C15 |
| 2 | 220pF | Capacitor_SMD:C_0402_1005Metric | C11, C13 |
| 2 | DMP2305U | Package_TO_SOT_SMD:SOT-23 | U4, U6 |
| 1 | 0.1uF | Capacitor_SMD:C_0402_1005Metric | C8 |
| 1 | 100nF | Capacitor_SMD:C_0402_1005Metric | C5 |
| 1 | 10K | Resistor_SMD:R_0402_1005Metric | R7 |
| 1 | 1uF | Capacitor_SMD:C_0402_1005Metric | C9 |
| 1 | ASTX-H11-25.000MHZ-T | schemagic:SMD3225 | Q1 |
| 1 | ATmega328P-A | Package_QFP:TQFP-32_7x7mm_P0.8mm | U5 |
| 1 | BAT20JFILM | Diode_SMD:D_SOD-323 | D1 |
| 1 | GPSANT | Connector_PinHeader_1.27mm:PinHeader_1x02_P1.27mm_Vertical | J2 |
| 1 | HF ANT | Connector_PinHeader_1.27mm:PinHeader_1x02_P1.27mm_Vertical | J6 |
| 1 | I2C | Connector_PinHeader_1.27mm:PinHeader_1x02_P1.27mm_Vertical | J5 |
| 1 | ICSP | Connector_PinHeader_1.27mm:PinHeader_1x06_P1.27mm_Vertical | J3 |
| 1 | MAX-M10S | RF_GPS:ublox_MAX | U3 |
| 1 | MCP1754T-3302E_OT | schemagic:SOT95P270X145-5N | PS1 |
| 1 | Power | Connector_PinHeader_1.27mm:PinHeader_1x03_P1.27mm_Vertical | J1 |
| 1 | Resonator | schemagic:OSC_CSTCE16M0V53-R0 | Y2 |
| 1 | SERIAL | Connector_PinHeader_1.27mm:PinHeader_1x03_P1.27mm_Vertical | J4 |
| 1 | Si5351A-B-GT | Package_SO:MSOP-10_3x3mm_P0.5mm | Y1 |
Questions
How big is the Firefly PCB?
It measures 17 × 22.1 mm and has 4 copper layers, 1.6 mm thick.
What parts does the Firefly use?
39 parts, built around the ATMEGA328P-AU, DMP2305U, MAX-M10S and ASTX-H11-25.000MHZ-T. 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 Firefly KiCad files?
From the sjacksonhodum/firefly repository on GitHub, at the commit this page was made from: the board is firefly.kicad_pcb and its schematic firefly.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Firefly design in my own project?
Its repository states no licence, so its author keeps all rights: ask sjacksonhodum before reusing the design.
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