Hardware Engineer (PCB Design & Product Development) (RARR Job 6296)

We are seeking a dedicated Hardware Engineer to take our core system architecture, consisting of an ESP32, RS485 communication interfaces, 4G connectivity, and auxiliary sensors, from initial schematic to a manufacturable, field-deployable board. In this role, you will completely own the full hardware development lifecycle, managing everything from schematic capture and multi-layer PCB layout to BOM optimisation, prototyping, rigorous bench testing, and the eventual transition to small-batch manufacturing.

What You'll Design & Build

• Edge gateway PCB - ESP32-S3 or STM32-based, RS485 transceiver (MAX485/SP3485), 4G modem (SIM7600), power regulation, status LEDs, DIN-rail or wall-mount enclosure
• Power supply design - AC/DC 5V/3.3V regulation from 12V DC adapter or direct 230V AC input; protection circuits (overvoltage, reverse polarity, ESD)
• RS485 interface - isolated RS485 transceiver, TVS protection, termination resistor design, EMI considerations near inverter
• Sensor interfaces - DS18B20 (1-Wire), I²C header for pyranometer, GPIO expansion
• PCB layout - 2-4 layer board, impedance control for USB/UART, thermal design for modem, RF keepout for Wi-Fi/BLE antenna
• Prototyping and bring-up - assemble and test proto boards, debug with oscilloscope and logic analyser, validate against firmware team requirements
• BOM management - component selection with multiple sourcing, cost optimisation for 100-1000 unit runs, LCSC/Mouser/Digi-Key availability
• Manufacturing transition - Gerber files, pick-and-place BOM, SMT assembly coordination with Indian PCB manufacturers (local vendors or reliable fab houses)

Required Skills

• PCB design EDA tool - KiCad (strongly preferred), Altium Designer, or EasyEDA at production level (not just demo boards)
• Schematic capture - component symbols, net naming, hierarchical design for complex boards
• PCB layout - component placement, trace routing, DRC clearance rules, layer stackup, via stitching for GND plane
• Power electronics basics - LDO vs SMPS selection, decoupling capacitor placement, thermal calculations
• Communication interfaces - UART, RS485, I²C, SPI, USB - schematic-level implementation
• Component selection - reading datasheets, selecting rated components, cross-referencing substitutes
• Gerber / fabrication output - generating and reviewing Gerber files, drill files, fab notes
• Basic test and measurement - multimeter, oscilloscope, understanding logic signal probing

Bonus Skills (Good to Have)

• Isolated RS485 design - digital isolators (ISO7721), isolated DC-DC for instrument-grade RS485
• 4G modem integration - RF antenna selection and placement, SIM slot, USB CDC data mode
• IEC / CE compliance awareness - EMC design practices, creepage/clearance for mains circuits
• Enclosure and mechanical design - DIN rail mounting clips, IP54 sealing, panel cutouts in Fusion 360 or SolidWorks
• SMPS design - flyback or buck converter design for efficiency at cost
• Firmware awareness - understanding what GPIO/UART/SPI lines the firmware team needs, not just placing connectors
• Component procurement in India - experience with Indian distributors, LCSC, Mouser India

You'll Thrive Here If You

• Have designed at least 1-2 PCBs that were manufactured and tested - show us Gerbers or photos
• Think about manufacturability - a board that works on a bench but fails at assembly is not a success
• Communicate design decisions - why this component, why this layout choice, what are the trade-offs
• Are comfortable working alongside firmware engineers - you understand what they're trying to do
• Can iterate fast - prototype, test, find the bug, fix, re-spin the board

What You Get

• Design a product that goes into the field at real solar sites - not an internal tool
• Work with firmware engineers, ML engineers, and field installation teams - full-stack hardware role
• Access to test equipment and prototyping budget
• Growth path into senior hardware engineer or hardware architect role