ESP32-S3 Table-Call System Firmware

Project Overview

The client was building a table-call product — wireless buttons that guests or staff press to call service, with events delivered instantly to a central point. They needed firmware that would survive the real world: unreliable Wi-Fi, drained batteries, power cuts, and devices that must be set up by non-technical users.

We delivered a complete ESP32-S3 firmware stack with a clean, modular manager-class architecture — every subsystem (connectivity, queueing, power, security) isolated and testable, so the codebase can grow with the product.

What We Built

• Captive portal provisioning — end users configure Wi-Fi from any phone, no app or technical knowledge needed
• Offline queue — call events are stored and delivered once connectivity returns; nothing is lost during outages
• Battery monitoring — real-time charge reporting so dead buttons never surprise the operator
• Per-device authentication — each unit carries its own credentials; devices can't be spoofed or cloned
• Reboot recovery — devices restore full state automatically after power loss
• Thorough documentation — the firmware is fully reproducible by the client's own team, with no lock-in to us

Outcome

Delivered on schedule, covering the full agreed scope. The client highlighted the clean separation of concerns in the architecture and the documentation quality — and invited us to collaborate on future work.

★★★★★

"Tehsin delivered solid ESP32-S3 firmware for our IoT product on schedule. Code is clean and modular, with well-thought-out separation of concerns across the manager classes. He covered the full scope including captive portal provisioning, offline queue, battery monitoring, per-device auth, and reboot recovery. Documentation is thorough which makes the firmware reproducible without him. Professional communication. Recommended for IoT firmware work and would collaborate again."