Classroom Presence System, Funding & Budget
Bill of materials and cost estimates for the RFID track, current and paused stages.
Funding & Budget
Bill of Materials & Funding Ask
What's already covered, and the itemized hardware behind the RFID track. Later hardware stages are priced for reference but are not an active funding ask; see the Research Proposal for why that work is paused.
Current Funding Status
| Stage | Funding status | What it needs |
|---|---|---|
| Contact-Tap Prototype (current) | No new funding needed | Runs on the CrowPi board and demo tags the team already has; see bill of materials below for the tag SKU. |
| Later hardware stages | No active ask, paused | Priced below for reference. Not requested until the research cycles show this hardware is worth building. |
Current Bill of Materials
Already covered by hardware the team has on hand. Listed here for reference and as the SKU to re-order from if more demo tags are needed.
| Item | Spec | Est. cost | Notes | Link |
|---|---|---|---|---|
| MIFARE Classic 1K keychain RFID fob (pack of 10) | ISO14443A, 13.56MHz, S50 chip, ABS+PC keychain fob, roughly 40×30×3mm | $7.99 per 10-pack ($0.80/tag) | The demo tags currently used with the CrowPi reader. Same MIFARE Classic 1K family the real student tags would need if the classroom pilot resumes, so this is also the reference SKU for scaling that order up. | Amazon |
Paused Hardware Stages, Priced for Reference
Not an active funding ask. Priced now so a real number exists if the research cycles show this hardware is worth building; see the Research Proposal for why it's paused.
Classroom pilot: adhesive tags
| Item | Spec | Est. cost | Notes | Link |
|---|---|---|---|---|
| MIFARE Classic 1K round adhesive NFC/RFID sticker (pack of 40) | ISO14443A, 13.56MHz, 1K byte memory, 1 inch (25mm) round, self-adhesive | $7.97 per 40-pack (about $0.20/tag) | Same chip family as the current keychain tags, so it works with the existing CrowPi reader unchanged. Small enough to apply directly to a playing card face. One 40-pack comfortably covers a 20 to 34 student class with spares for misprints or reissues. | Amazon |
UHF doorway transition
Room and door-table setup are confirmed. The teacher supplied concrete RF specs for the initial door-table test rig below.
| Item | Spec | Est. cost | Notes | Link |
|---|---|---|---|---|
| Rainy UHF Pi HAT (Complete Kit) | 865 to 870MHz (EU) or 915 to 928MHz (US), up to 200 tags/sec, 18 to 26dBm adjustable power, EPC Gen2V2 / ISO 18000-63, Cortex-M4 (ThinkMagic M6e Nano) | To be confirmed, check listing | The kit our teacher linked. Compatible with Pi 3/4/5/Zero/Zero 2W. | shop.sb-components.co.uk |
| Raspberry Pi 4 Kit with UHF HAT | Bundles a Pi 4 with the HAT above | To be confirmed, check listing | Simpler single order if we don't already have a spare Pi. | shop.sb-components.co.uk |
| U.FL (IPEX) to SMA female bulkhead pigtail cable | RG178, roughly 10 to 15cm, kept short to avoid signal loss at 900MHz | About $5 per pair | Adapts the HAT's onboard U.FL connector to a standard SMA test antenna. | Amazon |
| Test antenna: 5dBi 900MHz omnidirectional whip, SMA male | 868/915MHz | About $7 to $15 | Starting antenna for the door-table setup. Reader output power needs 20 to 26dBm; below that, range drops under 1m. | Amazon |
| Tamper-evident UHF tag (self-destructive antenna) | Antenna breaks on removal | About $0.10 per tag | Matches the tamper-proof requirement directly. | rfidtagworld.com |
| On-metal UHF tag (anti-metal, pack of 10) | ISO18000-6C, EPC Class1 Gen2, waterproof | To be confirmed, check listing | Confirmed good by teacher for laptop-lid mounting; standard UHF tags detune badly near metal. | Amazon |
| Standard adhesive UHF inlay tag, Alien H3 chip (pack of 100) | ISO18000-6C, long range | About $0.15 to $0.25 per tag ($15 to $25 per pack) | Teacher recommends Alien H3 or Impinj Monza 4/5 chips. Larger inlays reach 3 to 4m range; micro or button tags drop to 1 to 2m. Use on non-metal mount points. | Amazon |
Rough UHF-stage estimate: the items with confirmed pricing above total roughly
$30 to $50 (cable, test antenna, and a small batch of tamper and Alien H3 tags), reference pricing only, not a current request. The Pi/HAT kit and on-metal tag pack prices still need to be pulled from their current listings before a full estimate can be finalized, whenever this stage actually resumes.
Open Questions, If This Stage Resumes
- Room measurements: actual dimensions and door layout of the confirmed classroom would be needed to size a full-room antenna upgrade and produce a real cost estimate.
- Confirmed Pi/HAT and on-metal-tag pricing: current listing prices would need to be pulled to finalize a real total.
Project Team
Phase 1, Working Prototype