SMALL ESP32 Firmware for AWS IoT Data Logging

Job ID: 39918685

Budget: €300 – €500 EUR

Project: ESP32 (ESP-IDF) Firmware for AWS IoT Data Logging
Description

We are looking for a developer to implement firmware for an ESP32-S3 (16 MB flash) device that monitors an analog input, detects transitions, and publishes event data to AWS IoT Core via MQTT over TLS.

The firmware must:

Continuously sample one analog input and detect transitions based on a configurable threshold.

Store transition data and counters in a circular buffer in flash.

Periodically or conditionally publish data to AWS IoT Core using device certificates.

Retrieve AWS certificates from a web service when needed.

Subscribe to a shadow topic for configuration parameters and commands (RESET, TRANSMIT ALL, SOFTWARE UPDATE, etc.).

The full firmware specification (parameters, data format, PUB/SUB logic, and initialization process) is provided in the attached document.

Requirements

Strong experience with ESP-IDF, FreeRTOS, and AWS IoT Core (MQTT over TLS).

Familiar with flash memory management (NVS/SPIFFS) and REST API integration.

Able to deliver clean, well-documented C/C++ code.

To ensure real understanding, please include in your proposal:
Which esp_adc API you would use for threshold detection and how you would store certificates securely in ESP-IDF.

(Generic or automated proposals will not be considered.)