Custom ESP-IDF firmware and KiCad-designed PCB for a low-power LoRa environmental sensor network. This repository contains the sink node firmware — the receiver that collects raw telemetry from a cluster of distributed logger nodes, tags and stores it locally, and periodically forwards it downstream in batches.
This sink node receives raw sensor data transmitted over LoRa by a cluster of distributed logger nodes in the field. Each incoming transmission is tagged with the originating device's name/ID and written to local storage. Rather than forwarding data immediately, the sink accumulates readings over an extended interval — roughly one to two days — before forwarding the batched dataset downstream. This reduces network/forwarding overhead and allows the sink to operate reliably even if the downstream connection is intermittent.
- Custom LoRa receiver driver written in C (
LoRa/LoRa.c,LoRa/LoRa.h) — no off-the-shelf library dependency - Built on ESP-IDF for the ESP32-C6, enabling direct hardware control and fine-grained power management
- Per-device tagging: incoming packets are attributed to their originating logger node before storage
- Local buffering with scheduled, batched forwarding (configurable interval, currently ~1–2 days) rather than per-packet transmission
- Reproducible dev environment via
.devcontainer - Custom PCB schematic designed in KiCad
- MCU: ESP32-C6
- Radio: SX1276 (LoRa)
- Role: Sink / receiver node — aggregates data from a cluster of logger nodes over LoRa
- PCB: Custom schematic designed in KiCad — see
/hardware/schematic
| PCB — Top | PCB — Bottom |
|---|---|
|
 |
KiCad schematic and project files: hardware/schematic
Note: This repository currently includes the KiCad schematic (
PCB.kicad_sch) and project file (PCB.pro). The PCB layout file will be added once finalized.
- Receive — The sink listens continuously for LoRa transmissions from any logger node in the cluster.
- Tag — Each incoming payload is associated with the sending device's name/ID so readings can be traced back to their source.
- Store — Tagged readings are written to local storage on the sink node.
- Buffer — Data accumulates locally rather than being forwarded immediately after each reception.
- Forward — After a configured interval (currently ~1–2 days), the accumulated batch is forwarded downstream.
esp32-lora-environmental-datalogger-sink/
├── main/
│ ├── main.c # Application entry point and sink node logic
│ └── CMakeLists.txt
├── LoRa/
│ ├── LoRa.c # Custom LoRa driver implementation
│ └── LoRa.h
├── hardware/
│ ├── schematic/
│ │ ├── PCB.kicad_sch # KiCad schematic
│ │ └── PCB.pro # KiCad project file
│ └── Images/
│ ├── PCB_Top.jpg
│ └── PCB_Bottom.jpg
├── .devcontainer/ # Reproducible dev environment config
├── .vscode/ # Editor configuration
├── CMakeLists.txt # Project-level ESP-IDF build config
└── sdkconfig # ESP-IDF project configuration
This project uses ESP-IDF.
# Set up ESP-IDF environment
. $HOME/esp/esp-idf/export.sh
# Clone the project
git clone https://github.com/SuryaTejaJakka14/esp32-lora-environmental-datalogger-sink.git
cd esp32-lora-environmental-datalogger-sink
# Configure, build, and flash
idf.py set-target esp32c6
idf.py build
idf.py -p [PORT] flash monitorThe schematic was designed from scratch in KiCad to integrate the ESP32-C6, SX1276 LoRa module, and supporting power circuitry for the sink node.
- Schematic and project files:
hardware/schematic - Board photos:
hardware/Images
- Finalize and add the KiCad PCB layout file (
.kicad_pcb) - Make the forwarding interval configurable via
Kconfig/sdkconfigrather than hardcoded - Add secure communication (TLS/authentication) for the downstream forwarding step
- Add power optimization / sleep mode tuning for extended field deployment
- Job Intelligence Data Pipeline — data engineering and automation pipeline
Surya Teja Jakka
Data & IoT Engineer | Embedded Systems | Data Pipelines
- GitHub: @SuryaTejaJakka14
- LinkedIn: linkedin.com/in/teja-j14