What did you personally accomplish this week on the project?
This week I successfully submitted our PCB fabrication order to the manufacturing house after resolving the procurement setup issues from last week. I confirmed the production timeline – we’re looking at a 10-business-day turnaround for fabrication plus 3 days for assembly, putting our expected delivery around November 7th.
I completed the component procurement process, ordering all remaining parts from our approved vendors. The majority of components are stocked and will arrive within 5-7 business days. However, I identified two long-lead-time components: the IRLZ44N MOSFET switching transistors (3-week lead time) and the TUSB1064 USB redriver IC (2-week lead time). I expedited shipping on both to compress delivery to approximately 2 weeks, which still keeps us on schedule for our first prototype assembly.
I developed a comprehensive assembly procedure document that details the manual assembly process for the through-hole components including USB Type-A connectors and test points. The document includes step-by-step instructions with reference images, soldering temperature specifications for different component types, and quality checkpoints to verify proper connections before powering up the board.
I drafted the initial testing and bring-up plan, which outlines a systematic approach to first-power scenarios. The plan starts with visual inspection and continuity testing of critical nets (VBUS, GND, USB differential pairs), progresses through low-power functional verification of the FTDI interface, and culminates in full VBUS power cycling tests with actual failed USB drives. I’ve identified the test equipment we’ll need and confirmed availability of oscilloscopes, vector network analyzers for impedance measurements, and USB protocol analyzers in our lab space.
Finally, I met with Apollo to review the hardware-software interface requirements and confirmed that our GPIO assignments for VBUS power control align with the PyFTDI software architecture. We identified the specific timing requirements for power cycling sequences and the status feedback signals needed for recovery progress monitoring.
Is your progress on schedule or behind? If you are behind, what actions will be taken to catch up to the project schedule?
My progress is on schedule. All planned deliverables were completed this week. The component lead times are within acceptable ranges and won’t impact our critical path since software development can proceed in parallel. I’ve built in buffer time for any unexpected delays during board bring-up.
What deliverables do you hope to complete in the next week?
Next week I plan to:
- Finalize the testing and bring-up plan with detailed test procedures for USB signal integrity verification and power cycling characterization
- Receive and inventory the standard lead-time components (bulk capacitors, resistors, ferrite beads) to verify quantities and part numbers against the BOM
- Prepare the lab workspace with all necessary test equipment including oscilloscope, multimeter, and USB protocol analyzer
- Create a hardware interface specification document detailing GPIO pin assignments, VBUS switching timing requirements, and USB enumeration signal monitoring points
- Develop a risk mitigation strategy for the board bring-up phase, including backup plans if initial impedance measurements fall outside tolerance or VBUS rise times exceed specifications
- Begin preliminary discussions with Apollo on the PyFTDI integration to ensure smooth hardware-software handoff when boards arrive
Part A written by: Mars
Part B written by: Mars
Part A: Global Factors Consideration
Our FlashRescue USB data recovery solution addresses a critical global need that transcends geographic and economic boundaries – the need to recover irreplaceable personal data from failed USB drives. While data recovery services exist, they’re concentrated in developed markets and priced at $300-$1500 per recovery, making them economically inaccessible to the majority of the world’s population. This pricing structure effectively means that users in developing economies face permanent data loss when drives fail, even though the technical barriers to recovery aren’t insurmountable.
The hardware design I’ve developed explicitly considers global accessibility through several key decisions. The power management circuitry accommodates USB power delivery from various host sources worldwide, handling the voltage variations and noise characteristics present in different regions’ USB implementations. More fundamentally, the use of widely-available commodity components (FTDI FT2232H, standard MOSFETs, common USB redrivers) rather than specialized recovery hardware means the design can be replicated anywhere these components are available – which includes most countries with electronics distribution networks.
The impedance-controlled 6-layer PCB design, while adding cost, serves a global accessibility purpose beyond just signal integrity. Failed USB drives often exhibit degraded electrical characteristics – weak signals, timing violations, or marginal compliance with USB specifications. By implementing robust signal conditioning with the TUSB1064 redriver and maintaining tight impedance control, the hardware can successfully interface with drives that wouldn’t work with simpler circuits. This is particularly important for users in regions where drives may have experienced harsher operating conditions – extreme temperatures, unstable power, physical stress – making electrical degradation more likely.
Perhaps most importantly, the open-source nature of both hardware and software enables global adaptation and improvement. Users with electronics skills anywhere in the world can build, modify, and improve the design. The comprehensive documentation and clear derivations I’ve provided in the hardware specifications allow technically-capable individuals to understand not just what the design does, but why each decision was made. This educational transparency supports a global community of practitioners who can adapt the design for local conditions, share improvements, and collectively advance data recovery accessibility. For users in regions without access to professional recovery services, this community-based approach may represent their only viable option for recovering critical data.
Part B: Cultural Factors Consideration
The FlashRescue design acknowledges that people’s relationships with their data vary significantly across cultural contexts, and these differences influence both what constitutes “important data” and how recovery should be approached. In some Western contexts, USB drives primarily store convenience copies of data that exists elsewhere – documents synced to cloud services, photos backed up automatically. However, in many global contexts, USB drives serve as primary or sole storage for irreplaceable content: family photos with no other copies, small business financial records, academic work, or personal documents that cannot be entrusted to cloud services.
Cultural attitudes toward data privacy and ownership significantly influence the recovery solution’s design requirements. The hardware architecture I’ve implemented maintains complete user control throughout the recovery process, with no cloud dependencies, no required internet connectivity, and no data transmission to external services. This design choice respects cultural and individual values around data privacy – whether driven by professional confidentiality requirements, concerns about government surveillance, religious or cultural sensitivities around image capture and storage, or simply personal preference for data sovereignty. Users maintain physical possession of their drive throughout recovery, and the open-source nature of the software means there are no hidden data collection mechanisms.
The technical accessibility design also reflects cultural considerations around technology adoption and self-sufficiency. Some cultures emphasize learning technical skills and performing repairs independently rather than relying on service providers. The modular hardware design with clearly-labeled through-hole components and the educational documentation support this value system by making the technology understandable and maintainable by technically-inclined users. The command-line interface, while perhaps less approachable than a graphical interface, provides transparency into the recovery process that respects users who want to understand exactly what operations are being performed on their data.
Additionally, the cost structure (<$200 for a reusable tool versus $300-$1500 per recovery) enables a community-based recovery model where technically capable individuals can help friends, family, or community members recover data. This aligns with cultural values in communities that emphasize mutual aid and collective problem-solving rather than purely commercial service relationships. The open documentation and adaptable design support this use case by making it feasible for community workshops, repair cafes, or informal technology support networks to offer recovery services.