# Offline Password Manager bcdb ## Description Secure offline password manager using Arduino Pro Micro, MB85RC256V F-RAM, detachable Nokia 5110 LCD, rotary encoder, and 3.3 V support circuitry. ## Project Details - **Owner:** 4m12tronica - **Created:** 7/5/2026 - **Last Updated:** 7/5/2026 - **Visibility:** Public - **Human Interface:** Display - **Domain:** Security - **Operating Voltage:** 5V - **Connectivity:** I2C - **Implementation Details:** Arduino Pro Micro with 3.3 V peripherals and detachable LCD ## Key Components ### J1 — [PPPC081LFBN-RC](https://www.flux.ai/adrian95/pppc081lfbn-rc~jm9.md) - Datasheet URL: https://drawings-pdf.s3.amazonaws.com/10492.pdf - Connector Type: Header - License: https://creativecommons.org/licenses/by/4.0/ - Connector Gender: Female - Connector Positions: 8 - Manufacturer Part Number: PPPC081LFBN-RC - Mount: PCB - Connector Pitch: 2.54mm - Part Type: Connectors - Manufacturer Name: Sullins **Pins:** - 1 [pin 1] - 2 [pin 2] - 3 [pin 3] - 4 [pin 4] - 5 [pin 5] - 6 [pin 6] - 7 [pin 7] - 8 [pin 8] ### SW1 — [PEC11L-4115F-S0020](https://www.flux.ai/lcsc/pec11l-4115f-s0020~0d3.md) - Manufacturer Name: BOURNS - LCSC Part Number: C143799 - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/1804140028_BOURNS-PEC11L-4115F-S0020_C143799.pdf - Role: Menu navigation encoder - Manufacturer Part Number: PEC11L-4115F-S0020 - JLCPCB Part Class: Extended Part - Part Type: Rotary Encoders - Product Info Url: https://lcsc.com/product-detail/Coded-Rotary-Switches_BOURNS_PEC11L-4115F-S0020_PEC11L-4115F-S0020_C143799.html - Package or Case Code: SW-TH_5P-L11.8-W12.0-P2.50-LS14.5 **Pins:** - 1 [pin 4] - 2 [pin 5] - 7 [pin 7] - 8 [pin 8] - A [pin 1] - B [pin 3] - C [pin 2] ### U2 — MB85RC256V - Package or Case Code: 8-SOIC - Manufacturer Name: Fujitsu - Manufacturer Part Number: MB85RC256V - Role: Nonvolatile credential storage - Datasheet URL: https://www.fujitsu.com/us/Images/MB85RC256V-DS501-00017-3v0-E.pdf - Part Type: Integrated Circuits **Pins:** - A0 [pin 1] - A1 [pin 2] - A2 [pin 3] - SCL [pin 6] - SDA [pin 5] - VDD [pin 8] - VSS [pin 4] - WP [pin 7] ### U3 — [CD74HC4050M96](https://www.flux.ai/lcsc/cd74hc4050m96~8aaw.md) - Package or Case Code: SOIC-16_L9.9-W3.9-P1.27-LS6.0-BL - Datasheet URL: https://storage.googleapis.com/graviton-electric-symbols/document_assets/lcsc/1804242012_Texas-Instruments-CD74HC4050M96_C131932.pdf - Manufacturer Name: TI(德州仪器) - Product Info Url: https://lcsc.com/product-detail/74-Series_TI_CD74HC4050M96_CD74HC4050M96_C131932.html - Manufacturer Part Number: CD74HC4050M96 - Part Type: Buffers / Drivers - Role: LCD SPI/control level shifting - LCSC Part Number: C131932 - JLCPCB Part Class: Extended Part **Pins:** - 1A [pin 3] - 1Y [pin 2] - 2A [pin 5] - 2Y [pin 4] - 3A [pin 7] - 3Y [pin 6] - 4A [pin 9] - 4Y [pin 10] - 5A [pin 11] - 5Y [pin 12] - 6A [pin 14] - 6Y [pin 15] - GND [pin 8] - N.C [pin 16] - N.C/2 [pin 13] - VCC [pin 1] ### U4 — [AP2112K-3.3TRG1](https://www.flux.ai/adrian95/ap2112k-33trg1~zlq.md) - Manufacturer Name: Diodes Incorporated - Datasheet URL: https://www.diodes.com/assets/Datasheets/AP2112.pdf - Part Type: Integrated Circuit - Manufacturer Part Number: AP2112K-3.3TRG1 - Symbol Style: parametric-v1 - License: https://creativecommons.org/licenses/by/4.0/ - Role: 3.3V LDO regulator **Pins:** - EN [pin 3] - GND [pin 2] - NC [pin 4] - VIN [pin 1] - VOUT [pin 5] *The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/4m12tronica/offline-password-manager-bcdb~oo](https://www.flux.ai/4m12tronica/offline-password-manager-bcdb~oo).* --- *Generated from [https://www.flux.ai/4m12tronica/offline-password-manager-bcdb~oo](https://www.flux.ai/4m12tronica/offline-password-manager-bcdb~oo)*