LoRa/RFID device v4 (Heltec V4 + RC522, IP67, turnkey China)

**Categoría:** Engineering & Architecture Electronic Engineering (no 3D Modeling) **Tipo:** Fixed price, Expert level. Presupuesto visible: `[$1,200 – $2,500]` --- ## JOB DESCRIPTION (pegar tal cual) ### The product We have a working prototype of a two-device LoRa system: 1. **RFID reader** — Heltec WiFi LoRa 32 **V4** + MFRC522 (13.56 MHz) + Li-ion battery 2. **Gateway** — Heltec WiFi LoRa 32 **V4** + battery [ajusta si lleva red/alimentación fija] Both currently sit in 3D-printed enclosures we designed for the **V3** board. We're moving to the **V4** and to a proper **IP67 product manufactured and assembled in China**. We write the firmware ourselves — no firmware work needed. ### What we need Not an STL tweak. We need this taken from prototype to a batch of finished, sealed units delivered to Spain, where our only remaining step is flashing them. **Enclosure** - Pick a suitable **off-the-shelf IP67 plastic enclosure** (ABS/PC — no metal, it kills the RFID field and the antennas) and design the modifications to it. We don't want to pay for an injection mould at this volume. - Internal PCB mounts, battery retention, cable glands / IPEX-to-SMA bulkhead for the LoRa antenna. - **The RFID window is the critical part.** The RC522 only reads at 20–50 mm, so wall thickness and a metal-free keep-out around the coil decide whether this product works or not. - Lid must be **screwed with a gasket, openable and re-sealable** — we flash firmware after delivery. No glue, no ultrasonic welding. **Electronics** - A **carrier PCB** for the Heltec V4 integrating the RC522, battery + charging, power switch, status LED. If you think a custom ESP32-S3 + SX1262 board makes more sense at our volume, tell us — we want your honest read, not the expensive option. - We'll give you our V3 wiring and pin assignment. Note the V4 has GPIO layout changes vs the V3 and a different 2.4 GHz antenna design, so it needs reviewing rather than copying. **Manufacturing** - Find and vet a Chinese supplier that does **box build**: PCB + assembly + enclosure machining + final assembly + sealing + basic functional test + packaging. - Send them the complete file package and **deal with them directly** — quoting, DFM questions, anything missing — until we have an approved sample. Files: Gerbers + drill, BOM with LCSC/manufacturer part numbers, pick-and-place, assembly drawing, STEP + 2D drawings of the enclosure with tolerances, material/colour spec, and a simple assembly + test instruction sheet. If half of that list is unfamiliar, this isn't the right job for you. Make sure the batch ships with UN38.3 documentation for the batteries, otherwise it gets stuck in customs. ### Volume Pilot batch: **[X]** readers + **[Y]** gateways. Expected first year: **[Z]** units. ### It works when - RC522 reads a MIFARE Classic 1K card at ** more [25] mm** with the enclosure closed - LoRa range no worse than our current 3D-printed prototype - Enclosure is IP67 and can be opened, flashed and re-sealed by a non-technical person in a few minutes - Battery lasts **[X]** ### Compliance We sell in the EU, so the finished product needs CE / RED marking, and the V4's high-power version (28 dBm) has to be power-limited for the 868 MHz band. Tell us in your proposal whether you handle this, can recommend a lab, or hand it off to us. All three are fine — we just want to know. ### Payment We want to keep this simple: a single fixed-price payment, released once **the first sample from the factory arrives and works**. That's our starting point — we know it asks you to carry the project, so if you need a different structure, make us an offer and we'll talk. What we're not doing is paying for design files that never turn into working units. ### To apply Answer the questions below. Generic 3D-rendering portfolios won't be reviewed. Two-person teams (mechanical + electronics) welcome. --- ## SCREENING QUESTIONS 1. Link to a product you took from design to a manufactured batch in China. What volume, and did you handle the factory communication yourself? 2. How would you get reliable RC522 read range through a sealed IP67 enclosure? Be specific about material and wall thickness. 3. Do you already work with a Chinese factory that does box build? Name them. 4. At our volume, Heltec V4 as a module on a carrier board, or a custom ESP32-S3 + SX1262 PCB? Why?