# Coin Cell Binary Watch ## Description Simple CR2032-powered binary wristwatch with a low-power MCU, readable LED bit display, pushbutton wake/time setting, and PCB shape suitable for a 3D-printed case. ## Project Details - **Owner:** cythonicpy - **Created:** 5/26/2026 - **Last Updated:** 5/27/2026 - **Visibility:** Public ## Key Components ### BT1 — BAT-HLD-001 - Part Type: Connector - Manufacturer Part Number: BAT-HLD-001 - Role: Power Source - Role Details: CR2032 battery input; peak display load target about 12–15 mA momentary - Datasheet URL: https://linxtechnologies.com/wp/wp-content/uploads/battery_holder_overview_guide.pdf - Manufacturer Name: Linx Technologies Inc. - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - NEG [pin N1] - POS [pin P2] - POS [pin P1] ### D_PROT1 — Generic Schottky Diode - License: https://www.kicad.org/libraries/license/ - Package: SMA - Datasheet URL: Generic - Role: Protection - Role Details: Series Schottky reverse battery protection for coin-cell input - Manufacturer Part Number: Generic - Part Type: Diode - Manufacturer Name: Generic **Pins:** - A [pin 2] - C [pin 1] ### D1 — SM0805HCL - Role: Display - Datasheet URL: https://www.bivar.com/parts_content/Datasheets/SM0805HCL.pdf - Manufacturer Part Number: SM0805HCL - License: https://creativecommons.org/licenses/by/4.0/ - Role Details: 0805 red binary display LED; driven momentarily at low current from MCU - Manufacturer Name: Bivar Inc. - Part Type: LED **Pins:** - A [pin 2] - K [pin 1] ### J1 — TSW-103-07-G-D - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: Connector - Role: Programming Connector - Manufacturer Name: Samtec Inc. - Datasheet URL: https://suddendocs.samtec.com/prints/tsw-xxx-xx-x-x-xx-xxx-footprint.pdf - Manufacturer Part Number: TSW-103-07-G-D - Role Details: SWD header: VDD, GND, SWDIO, SWCLK, NRST, NC **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] - 5 [pin 5] - 6 [pin 6] ### LED1 — SM0805HCL - Role Details: 0805 red binary display LED; driven momentarily at low current from MCU - Manufacturer Part Number: SM0805HCL - Datasheet URL: https://www.bivar.com/parts_content/Datasheets/SM0805HCL.pdf - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: LED - Role: Display - Manufacturer Name: Bivar Inc. **Pins:** - A [pin 2] - K [pin 1] ### LED10 — SM0805HCL - Part Type: LED - Role Details: 0805 red binary display LED; driven momentarily at low current from MCU - Manufacturer Name: Bivar Inc. - Role: Display - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: SM0805HCL - Datasheet URL: https://www.bivar.com/parts_content/Datasheets/SM0805HCL.pdf **Pins:** - A [pin 2] - K [pin 1] ### LED11 — SM0805HCL - Manufacturer Part Number: SM0805HCL - Datasheet URL: https://www.bivar.com/parts_content/Datasheets/SM0805HCL.pdf - Role: Display - Role Details: 0805 red binary display LED; driven momentarily at low current from MCU - Manufacturer Name: Bivar Inc. - Part Type: LED - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - A [pin 2] - K [pin 1] ### LED2 — SM0805HCL - Role: Display - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: LED - Manufacturer Name: Bivar Inc. - Role Details: 0805 red binary display LED; driven momentarily at low current from MCU - Manufacturer Part Number: SM0805HCL - Datasheet URL: https://www.bivar.com/parts_content/Datasheets/SM0805HCL.pdf **Pins:** - A [pin 2] - K [pin 1] ### LED3 — SM0805HCL - Datasheet URL: https://www.bivar.com/parts_content/Datasheets/SM0805HCL.pdf - Manufacturer Part Number: SM0805HCL - Role Details: 0805 red binary display LED; driven momentarily at low current from MCU - Role: Display - Manufacturer Name: Bivar Inc. - Part Type: LED - License: https://creativecommons.org/licenses/by/4.0/ **Pins:** - A [pin 2] - K [pin 1] ### LED4 — SM0805HCL - Manufacturer Part Number: SM0805HCL - Datasheet URL: https://www.bivar.com/parts_content/Datasheets/SM0805HCL.pdf - Part Type: LED - Manufacturer Name: Bivar Inc. - License: https://creativecommons.org/licenses/by/4.0/ - Role: Display - Role Details: 0805 red binary display LED; driven momentarily at low current from MCU **Pins:** - A [pin 2] - K [pin 1] ### LED5 — SM0805HCL - Part Type: LED - Manufacturer Name: Bivar Inc. - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: SM0805HCL - Datasheet URL: https://www.bivar.com/parts_content/Datasheets/SM0805HCL.pdf - Role: Display - Role Details: 0805 red binary display LED; driven momentarily at low current from MCU **Pins:** - A [pin 2] - K [pin 1] ### LED6 — SM0805HCL - License: https://creativecommons.org/licenses/by/4.0/ - Part Type: LED - Manufacturer Name: Bivar Inc. - Role Details: 0805 red binary display LED; driven momentarily at low current from MCU - Role: Display - Datasheet URL: https://www.bivar.com/parts_content/Datasheets/SM0805HCL.pdf - Manufacturer Part Number: SM0805HCL **Pins:** - A [pin 2] - K [pin 1] ### LED7 — SM0805HCL - Manufacturer Name: Bivar Inc. - Part Type: LED - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Part Number: SM0805HCL - Role Details: 0805 red binary display LED; driven momentarily at low current from MCU - Datasheet URL: https://www.bivar.com/parts_content/Datasheets/SM0805HCL.pdf - Role: Display **Pins:** - A [pin 2] - K [pin 1] ### LED8 — SM0805HCL - License: https://creativecommons.org/licenses/by/4.0/ - Manufacturer Name: Bivar Inc. - Part Type: LED - Role: Display - Role Details: 0805 red binary display LED; driven momentarily at low current from MCU - Datasheet URL: https://www.bivar.com/parts_content/Datasheets/SM0805HCL.pdf - Manufacturer Part Number: SM0805HCL **Pins:** - A [pin 2] - K [pin 1] ### LED9 — SM0805HCL - Datasheet URL: https://www.bivar.com/parts_content/Datasheets/SM0805HCL.pdf - Manufacturer Part Number: SM0805HCL - License: https://creativecommons.org/licenses/by/4.0/ - Role Details: 0805 red binary display LED; driven momentarily at low current from MCU - Role: Display - Part Type: LED - Manufacturer Name: Bivar Inc. **Pins:** - A [pin 2] - K [pin 1] ### SW1 — PTS810SJK250SMTRLFS - Manufacturer Part Number: PTS810SJK250SMTRLFS - Datasheet URL: https://datasheet.lcsc.com/lcsc/1810121650_C-K-PTS810SJK250SMTRLFS_C221896.pdf - Part Type: Switch - Manufacturer Name: C&K - Role: User Input - LCSC Part Number: C221896 - Role Details: Low-profile tactile switch for binary watch user control **Pins:** - P1 [pin 1] - P3 [pin 3] ### SW2 — PTS810SJK250SMTRLFS - LCSC Part Number: C221896 - Role: User Input - Manufacturer Name: C&K - Datasheet URL: https://datasheet.lcsc.com/lcsc/1810121650_C-K-PTS810SJK250SMTRLFS_C221896.pdf - Part Type: Switch - Role Details: Low-profile tactile switch for binary watch user control - Manufacturer Part Number: PTS810SJK250SMTRLFS **Pins:** - P1 [pin 1] - P3 [pin 3] ### SW3 — PTS810SJK250SMTRLFS - Manufacturer Name: C&K - Role Details: Low-profile tactile switch for binary watch user control - LCSC Part Number: C221896 - Manufacturer Part Number: PTS810SJK250SMTRLFS - Role: User Input - Part Type: Switch - Datasheet URL: https://datasheet.lcsc.com/lcsc/1810121650_C-K-PTS810SJK250SMTRLFS_C221896.pdf **Pins:** - P1 [pin 1] - P3 [pin 3] ### U1 — STM32L433CBT6 - Manufacturer Part Number: STM32L433CBT6 - Role: Microcontroller - Datasheet URL: https://www.st.com/content/ccc/resource/technical/document/datasheet/f7/a0/fc/27/24/4e/4f/3f/DM00257192.pdf/files/DM00257192.pdf/jcr:content/translations/en.DM00257192.pdf - Role Details: Low-power MCU driving binary LED display and keeping time from 32.768 kHz LSE crystal - Part Type: Microcontroller - Manufacturer Name: STMicroelectronics **Pins:** - NRST [pin 7] - PA0 [pin 10] - PA1 [pin 11] - PA10 [pin 31] - PA11 [pin 32] - PA12 [pin 33] - PA13 [pin 34] - PA14 [pin 37] - PA15 [pin 38] - PA2 [pin 12] - PA3 [pin 13] - PA4 [pin 14] - PA5 [pin 15] - PA6 [pin 16] - PA7 [pin 17] - PA8 [pin 29] - PA9 [pin 30] - PB0 [pin 18] - PB1 [pin 19] - PB10 [pin 21] - PB11 [pin 22] - PB12 [pin 25] - PB13 [pin 26] - PB14 [pin 27] - PB15 [pin 28] - PB2 [pin 20] - PB3 [pin 39] - PB4 [pin 40] - PB5 [pin 41] - PB6 [pin 42] - PB7 [pin 43] - PB8 [pin 45] - PB9 [pin 46] - PC13 [pin 2] - PC14 [pin 3] - PC15 [pin 4] - PH0 [pin 5] - PH1 [pin 6] - PH3 [pin 44] - VBAT [pin 1] - VDD [pin 48] - VDD [pin 24] - VDDA [pin 9] - VDDUSB [pin 36] - VSS [pin 35] - VSS [pin 47] - VSS [pin 23] - VSSA [pin 8] ### Y1 — ECS-.327-6-34QCS-TR - Part Type: Oscillator - License: https://creativecommons.org/licenses/by/4.0/ - Role Details: 6 pF load 32.768 kHz LSE crystal for watch timekeeping - Datasheet URL: https://ecsxtal.com/store/pdf/ECX-34Q.pdf - Role: Clock - Manufacturer Name: ECS Inc. - Manufacturer Part Number: ECX-.327-CDX-2096 **Pins:** - 1 [pin 1] - 2 [pin 2] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/cythonicpy/coin-cell-binary-watch~ar](https://www.flux.ai/cythonicpy/coin-cell-binary-watch~ar).* --- *Generated from [https://www.flux.ai/cythonicpy/coin-cell-binary-watch~ar](https://www.flux.ai/cythonicpy/coin-cell-binary-watch~ar)*