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2 layers103.5 × 77 mmHh3.0, the printed circuit board in 3D

The LIFE Node is a smart, decentralized solar harvesting edge device designed to function as an intelligent microgrid component.

Size
103.5 × 77 mm
Copper layers
2
Thickness
1.6 mm
Parts
30
Nets
42
Pads
169
Tracks, vias
144, 8
Pours
2
Routed
Yes
KiCad
KiCad 9.0 (file 20241229)
Created
11 Apr 2026
Updated
12 Apr 2026

Overview

Hh3.0 is an open-source printed circuit board by dhruvdabur, from the dhruvdabur/Hardware-hackathon-3.0 repository on GitHub. It is a 2-layer board of 103.5 × 77 mm with 30 parts on 42 nets, routed with 144 tracks and 8 vias.

It is built around the BC547. Its parts include 8 resistors, 4 connectors, 3 diodes, 2 ICs and 1 transistor.

Main components

1

README

README.md

The LIFE Node

Local Intelligence for Energy

The LIFE Node is a smart, decentralized solar harvesting edge device designed to function as an intelligent microgrid component. Unlike traditional reactive solar charge controllers, the LIFE Node combines edge AI, multimodal sensor fusion, predictive maintenance, and peer-to-peer energy sharing to make solar systems more efficient, resilient, and autonomous.

It is built to do more than just charge a battery. It can:

  • adapt charging behavior based on weather and sensor inputs,
  • protect long-term lithium-ion battery health,
  • detect panel soiling and maintenance needs,
  • and communicate with nearby nodes to balance local energy demand.

Problem Statement

Conventional small-scale solar charging systems are mostly static and reactive. They usually:

  • charge batteries without considering future solar availability,
  • lack awareness of battery aging and health,
  • cannot detect maintenance issues like dust accumulation,
  • and operate as isolated units instead of intelligent networked energy nodes.

This leads to:

  • reduced battery lifespan,
  • inefficient energy harvesting,
  • unnecessary maintenance delays,
  • and poor resource sharing across local energy systems.

The LIFE Node addresses these limitations by introducing local intelligence directly at the edge.


Core Idea

The LIFE Node transforms a basic solar charging setup into a self-aware solar microgrid node.

It does this through four major pillars:

  1. Software-defined adaptive charging
  2. Multimodal sensor fusion with predictive AI
  3. Autonomous predictive maintenance
  4. Decentralized microgrid load sharing

Key Features

1. Software-Defined Adaptive Charging

The charging backbone is based on the CN3065 solar charge controller, chosen for its simplicity and efficiency.

What makes it smarter?
  • The CN3065 includes an internal 8-bit ADC that adjusts charging current according to real-time solar panel output.
  • This helps prevent panel voltage collapse during sudden drops in sunlight.
Hardware modification

To make charging behavior software-controlled, a BJT switch modification is added to the ISET pin:

  • A transistor is used to switch an additional resistor in parallel.
  • This allows the microcontroller to toggle between:
    • Slow / Trickle Charge
    • Fast Charge
Why this matters

This enables the system to:

  • aggressively charge before poor weather,
  • preserve battery health during favorable solar periods,
  • and make charging decisions based on both present and future conditions.

2. Multimodal Sensor Fusion & Predictive AI

The LIFE Node acts as an edge intelligence unit by combining local sensor readings with cloud weather forecasts.

Local sensing
  • LDR for real-time light intensity / irradiance estimation
  • DHT11 for ambient temperature and humidity
External data
  • Weather forecast data via Weather APIs / Sarvam AI integration
Intelligent decision-making

The node fuses:

  • current sunlight levels,
  • local temperature and humidity,
  • and forecasted weather patterns

to predict future energy availability.

Example behavior
  • If cloudy or stormy conditions are expected, the node switches to Fast Charge to build battery reserves.
  • If a sunny week is predicted, it defaults to Slow Charge to reduce stress on the battery.

This turns solar charging into a forecast-aware proactive process.


3. Autonomous Predictive Maintenance

Solar systems often lose efficiency due to dust, dirt, or bird droppings, but these issues usually go unnoticed until output drops significantly.

The LIFE Node solves this with Power Loss Analysis.

How it works
  • The system stores historical solar output under known weather and light conditions.
  • Over time, it builds a baseline of expected normal performance.
  • It then compares:
    • expected solar power from current LDR + weather data
    • against actual power entering the charge controller
Result

When there is a sustained mismatch under otherwise good sunlight conditions, the node can infer that the panel may be dirty or partially obstructed.

Benefit

This enables:

  • automatic cleaning alerts
  • smarter maintenance scheduling
  • improved long-term energy yield

In short, the LIFE Node acts as its own maintenance supervisor.


4. Decentralized Microgrid Load Sharing

Each LIFE Node is not just a charger, but a networked energy participant.

Local learning

The node tracks its connected load and builds a daily consumption profile to understand:

  • when demand peaks,
  • when surplus is likely,
  • and when battery reserves are needed.
Node-to-node communication

Using Wi-Fi communication protocols such as:

  • MQTT
  • UDP

each node can broadcast its:

  • forecasted surplus,
  • forecasted deficit,
  • and local demand state

to neighboring nodes.

Real-time energy arbitration

Based on these shared states, the system decides whether to:

  • charge its own battery,
  • supply the local load directly,
  • or export surplus energy to a nearby node
Why this is powerful

By routing energy peer-to-peer across nearby nodes, the system can:

  • reduce transmission losses,
  • improve local resilience,
  • keep the microgrid balanced,
  • and avoid unnecessary centralized routing.

System Architecture

text
Solar Panel
   │
   ▼
CN3065 Charge Controller
   │
   ├── Battery Charging Path
   │
   └── Microcontroller-Controlled ISET Mod (BJT + Resistor Switching)
             │
             ▼
      Edge Microcontroller
             │
   ┌─────────┼─────────┐
   │         │         │
   ▼         ▼         ▼
 LDR       DHT11   Power/Voltage Monitoring
   │         │         │
   └─────────┴─────────┘
             │
             ▼
   Sensor Fusion + Prediction Logic
             │
   ┌─────────┼─────────┬─────────────┐
   │         │         │             │

Parts

30
QtyValueFootprintReferences
5VAL**Kicad_footprints.kicad_mod:Mouse_Bites_1.27mouse-bite-2mm-slot, mouse-bite-2mm-slot, mouse-bite-2mm-slot, mouse-bite-2mm-slot, mouse-bite-2mm-slot
3LEDLED_THT:LED_D3.0mm_ClearD1, D2, D3
3R_Small_USResistor_THT:R_Axial_DIN0204_L3.6mm_D1.6mm_P5.08mm_HorizontalR2, R3, R5
2DHTConnector_PinSocket_2.54mm:PinSocket_1x03_P2.54mm_VerticalJ5, J5
2LDR03OptoDevice:R_LDR_4.9x4.2mm_P2.54mm_VerticalR6, R6
1100kResistor_THT:R_Axial_DIN0204_L3.6mm_D1.6mm_P5.08mm_HorizontalR7
11kResistor_THT:R_Axial_DIN0204_L3.6mm_D1.6mm_P5.08mm_HorizontalR1
1BC547Package_TO_SOT_THT:TO-92_InlineQ1
1Conn_01x12_PinConnector_PinSocket_2.54mm:PinSocket_1x12_P2.54mm_VerticalJ1
1Conn_01x16_PinConnector_PinSocket_2.54mm:PinSocket_1x16_P2.54mm_VerticalJ3
1LOGOrm logo long 18x6:rm logo long 2 18x6G***
1PinHeader_1x04_P2.54mm_VerticalConnector_PinHeader_2.54mm:PinHeader_1x04_P2.54mm_VerticalSOLAR
1R_USResistor_THT:R_Axial_DIN0204_L3.6mm_D1.6mm_P5.08mm_HorizontalR4
1~hh_re:glyph-c3U1
1~hh_re:gmod-relay_2chU2

The 25 most common of 30 parts.

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Questions

How big is the Hh3.0 PCB?

It measures 103.5 × 77 mm and has 2 copper layers, 1.6 mm thick.

What parts does the Hh3.0 use?

30 parts, built around the BC547. The full list of its parts is on this page, with links to each part's symbol and footprint where PCBKit's library has them.

Where can I download the Hh3.0 KiCad files?

From the dhruvdabur/Hardware-hackathon-3.0 repository on GitHub, at the commit this page was made from: the board is PCB design/hh3.0.kicad_pcb and its schematic PCB design/hh3.0.kicad_sch. PCBKit opens the board in the browser, with nothing to install.

Can I use the Hh3.0 design in my own project?

Its repository states no licence, so its author keeps all rights: ask dhruvdabur before reusing the design.