4 layers
Eigentime32
captainchapster/Eigentime32
A self-contained pocket watch that keeps its own time for a decade. No GPS, one coin cell, one PCB.
53 parts1
2 layers
Ferris
rappet/ferris-badge1Small badge running on a coin cell using a STM32L031G6U with embassy.
- Copper layers
- 2
- Thickness
- 1.6 mm
- Parts
- 23
- Nets
- 37
- Pads
- 103
- Tracks, vias
- 90, 4
- Pours
- 4
- Routed
- Yes
- KiCad
- KiCad 8.0 (file 20240108)
- Created
- 13 Feb 2025
- Updated
- 13 Feb 2025
Overview
Ferris is an open-source printed circuit board by rappet, from the rappet/ferris-badge repository on GitHub. It is a 2-layer board with 23 parts on 37 nets, routed with 90 tracks and 4 vias.
It is built around the STM32L031G6U6, TPS613221ADBV and CR2032. Its parts include 7 capacitors, 4 resistors, 4 switches, 3 ICs and 2 diodes. It belongs with the STM32 and RISC-V boards of this library.
Main components
3
STM32L031G6U6
UFQFPN-28(4x4)-40℃~+85℃ 1.8V~3.6V 12bit 1KB 21 32 Bit 32KB 32MHz 8KB ARM Cortex-M0+ Built-in FLASH UFQFPN-28(4x4) Microcontrollers (MCU/MPU/SOC) ROHSSTMicroelectronicsMicrocontrollers (MCU/MPU/SOC)
TPS613221ADBV
SOT-23-5-40℃~+125℃@(TJ) 1 1.6MHz 3.3V 6.5uA 900mV~5.5V Boost Boost Built-in Fixed Yes SOT-23-5 DC-DC Converters ROHSTexas InstrumentsDC-DC Converters
CR2032
-- Unclassified goods ROHSMaxellUncategorised
README
README.mdFerris STM32L0 badge
Small badge running on a coin cell using a STM32L031G6U with embassy.
Known bugs
- BOOT0 is not connected
- Reverse polarity protection diode should be swapped with MOSFET
- Output caps could be larger to minimize peak current during PWM
- Shutdown microcontroller with external MOSFET
- Current power consumption when turned off was measured at ~16µF
Parts
23| Qty | Value | Footprint | References |
|---|---|---|---|
| 4 | 22u | Capacitor_SMD:C_0805_2012Metric_Pad1.18x1.45mm_HandSolder | C1, C2, C3, C4 |
| 4 | 33R | Resistor_SMD:R_0402_1005Metric | R1, R2, R3, R4 |
| 4 | SW_Push | Button_Switch_SMD:SW_Push_1P1T_XKB_TS-1187A | SW1, SW2, SW3, SW4 |
| 3 | 100n | Capacitor_SMD:C_0402_1005Metric | C5, C6, C7 |
| 2 | LED_Dual_KKA | LED_SMD:LED_LiteOn_LTST-S326 | D1, D2 |
| 1 | 4.7uH | Inductor_SMD:L_1008_2520Metric_Pad1.43x2.20mm_HandSolder | L1 |
| 1 | CH32V003JxMx | Package_SO:SOP-8_3.9x4.9mm_P1.27mm | U3 |
| 1 | CR2032 | Battery:BatteryHolder_Keystone_3034_1x20mm | BT1 |
| 1 | STM32L031G6U6 | Package_DFN_QFN:QFN-28_4x4mm_P0.5mm | U1 |
| 1 | SWD | SOIC Bite:SOIC_clipProgSmall | J2 |
| 1 | TPS613221ADBV | Package_TO_SOT_SMD:SOT-23-5_HandSoldering | U2 |
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Questions
What parts does the Ferris use?
23 parts, built around the STM32L031G6U6, TPS613221ADBV 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 Ferris KiCad files?
From the rappet/ferris-badge repository on GitHub, at the commit this page was made from: the board is board/ferris.kicad_pcb and its schematic board/ferris.kicad_sch. PCBKit opens the board in the browser, with nothing to install.
Can I use the Ferris design in my own project?
Its repository states no licence, so its author keeps all rights: ask rappet before reusing the design.