SIG.04865–867 MHZJOURNAL
The journal.
Long-form notes on the things I build: reverse-engineering RFID hardware, architecting real-time systems, and designing for the physical world.
Writing a Blog Nobody Reads
A confession about how tedious it is to keep updating a blog with almost zero subscribers and why I'm doing it anyway.
Printing a label and writing the chip in the same pass
An RFID label is a sticker with a radio in it. Printing one means the artwork and the chip encoding have to succeed together, and either can fail on its own.
Shipping updates to a box you cannot SSH into
The reader runs the whole stack now, and it sits behind a customer firewall I have no route to. Every part of the update path had to assume I get exactly one shot.
Counting parts with a camera, not a model
Someone needed loose components counted from a photo. I reached for a neural network first, then put it down and used plain OpenCV, and it worked better.
One database per customer
Why I gave every tenant its own SQLite file instead of a shared table with a company_id column, and what that bought me.
The network will drop, plan for it
Race timing runs on a laptop at a start line with terrible Wi-Fi. Here is how I stopped a flaky venue network from ever losing a tag read.
A tamper-evident passport without a blockchain
Every piece of jewellery carries a lifecycle history a customer can trust. I did it with SHA-256 hashes, not a blockchain, and here is why that was enough.
Reading RFID when there is no SDK
What I learned hand-writing a binary protocol for UHF readers over raw TCP: CRC framing, EPC parsing, and why the vendor DLL was a dead end.
One data model to rule the event
Event tech is five vendors duct-taped together. Building Vizha, I tried the opposite: ticket, gate tap, and wallet payment as the same record.
Designing for a trigger, not a mouse
Field apps live on a gun-grip PDA and a hardware trigger, not a trackpad. Here's how that changes every design decision, and why I mocked two full design languages first.
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