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OSHE I2C/UART Card

The OSHE I2C/UART Card is a community-developed expansion card providing I2C and UART interfaces in the Framework expansion card form factor1. Developed by the Open Source Hardware Enterprise (OSHE), a student team at Michigan Technological University, the card went through multiple design revisions over the 2025–2026 academic year and reached feature-complete status in April 20262.

Design

A key design challenge was whether to include both male and female pin headers on the same board — doing so would have required the card to extend outside the laptop's form factor, which the team wanted to avoid1. The solution was to create two separate PCB variants: one with female headers and one with male headers, both staying compact and compatible with the Framework expansion bay1.

The revised design includes a switch to toggle between I2C and UART modes and adds over-voltage protection against plugging in more than 5V on the Vo connector3. The card is otherwise electrically identical to the earlier revision3.

Framework supported OSHE's development by sending the team a Framework 13 motherboard and Cooler Master case for physical and electrical validation testing2.

Specifications

SpecificationDetails
InterfacesI2C, UART (switchable)3
PCB variantsFemale headers, male headers1
ProtectionOver-voltage protection (>5V on Vo)3
StatusFeature-complete (April 2026)2
OrganizationMichigan Technological University — OSHE1
LicenseOpen source1
RepositoryOSHE-Github/OSHE-Framework (GitHub)2
ProjectDescription
OSHE Mouse Dongle Hiding CardRecessed USB-A card for wireless dongles — another OSHE project
OSHE Magnetic Charging CardMagSafe-style magnetic charging card — another OSHE project
UART Expansion CardCommunity UART serial expansion card

Footnotes

  1. OSHE I2C Card Project — Framework Community (OSHE_Framework, November 2025) 2 3 4 5 6

  2. OSHE I2C Card Project — feature-complete update — Framework Community (OSHE_Framework, April 2026) 2 3 4

  3. OSHE I2C Card Project — revised design — Framework Community (OSHE_Framework, January 2026) 2 3 4