L.E. v 0.2 | NFC tags

Pavel

— 2 min read

NFC (Near-field communication) is the base of WCC (Wireless Command Control, if you don't know what is it and how it works, check this post). NFC includes 2 components - unpowered tags that can be placed under rails, on a road, on a train, etc., and a powered reader (which can be installed in a train if you put tags under rails, for example). When a train "A" with an NFC reader crosses a tag "B" placed under rails - all trains, signals, switchers, and other modules connected to this WCC network receive messages that "A" just crossed "B". Each module checks what should be done in case of this event (just skip or do some action - change the light, up barriers, etc). You can even stick an unpowered tag (around 8 x 8 mm) on a train if your train (N-Gauge and smaller) hasn't enough space for a reader module (around 12mm x 15mm) and put NFC reader module under rails.

In version 0.2 we implemented NFC logic. Of course, we just developed very basic logic to read the tag's ID and send information with this ID to a server if a reader detects a tag. NFC is an amazing technology but a bit complex to develop. We worked until 2 AM on some days, and we worked on weekends and totally spent around 260hours to get the first working NFC module. Yes, you can just use Arduino SDK but modules developed on Arduino cannot provide the same performance as modules developed using native SDKs. At first, you should implement the protocol to get information from NFC frontend on MCU, then tune up an NFC antenna using capacitors to get the best performance, and after you should adapt your firmware to work with this particular antenna design. Currently, we can only put powered readers under rails and stick tags on trains because our NFC development modules are big and we cannot install them inside trains. The final version should be flexible - you can install NFC readers where you want - in trains (est. dimensions are 12mm x 15mm + antenna 15mm x 15mm), under rails or road, and even in trucks and buses (HO-Gauge and bigger).

This week we finally got development modules for tiny TI drivers for brushed DC motors, soldered them, and already tested them. Just look how small are they (2 mm x 2 mm) and still can handle up to 1.5A

Development board with TI driver for brushed DC motors



What's new:

  • [Firmware] Added NFC reader module
  • [Hardware] Designed and soldered NFC reader development boards
  • [Hardware] Designed and soldered NFC antenna development boards
  • [API] Added POST /event to send messages about events (for example, tag detection) to the backend
  • [APP] Added UI to test NFC interactions

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