Client

Rahul Meters is a well-established manufacturer specializing in analog water meters. As the market shifted towards smart metering, Rahul Meters sought to innovate and remain competitive by integrating advanced technologies into their existing products.

Problem Statement

The primary challenge faced by Rahul Meters was the need to modernize their traditional analog water meters to meet the growing demand for smart, connected devices. The company required a solution that would integrate seamlessly into their existing meters without significantly increasing costs or compromising battery life.

Solution

TechShlok developed a comprehensive solution by integrating LoRa technology into the existing water meters. The team designed a custom PCB that included LoRa communication capabilities, enabling the meters to send data wirelessly once a day while ensuring long battery life. Advanced power management techniques and component selection were employed to achieve over 10 years of battery operation.

This solution evolved over two major design cycles:

Version 1 – A custom RF-based handheld and meter device ecosystem.
Version 2 – A full-fledged LoRaWAN-powered smart metering infrastructure, optimized for large-scale deployment.

Approach

Version 1 : RF-Based Handheld AMR System

System Architecture Overview
Version 1 consisted of two primary components:

RF Water Meter Unit: A battery-powered unit equipped with a sensor interface and an RF-enabled MCU with a projected operational lifespan of 5+ years.
Handheld Unit (HHU): A mobile device capable of wirelessly reading meter data, storing it locally, and transferring it via USB. Controlled via Bluetooth with an Android app.

Development Process: Phase-Wise Execution

Phase 1: POC and Initial Prototype

RF Platform Selection: The team chose an 868 MHz RF platform using an industry-grade Si1062 RF MCU for long-range, low-power communication.
PCB Design: A custom compact RF PCB was designed and fabricated. The components were manually soldered and verified using RF signal analyzers.
Sensor Integration: For data acquisition, an optical sensor was aligned with the mechanical spinning wheel inside the utility meters to capture real-time consumption data.
Enclosure Design: Custom 3D-printed enclosures were developed to make the PCBs dustproof, waterproof, and durable.

Phase 2: Optimization for Field Operations

Power Management: Initial testing revealed high battery consumption due to always-on operation. Engineers implemented a cyclic wake-sleep mechanism using the internal RTC of the Si1062, enabling periodic wake-ups to transmit data, significantly improving battery longevity.
Mobile Application Development: The HHU, originally designed with a button-operated LCD interface, was upgraded to operate over Bluetooth via an Android mobile app, making it more user-friendly and compact.
Memory and Communication: The HHU was equipped with 8GB onboard memory and USB data export capabilities.

Phase 3: Field Testing and Final Refinement

Field Trials: The system was tested extensively at client sites. The devices demonstrated a reliable communication range of 150–250 meters in real-world scenarios.
Circuit Protection: During prolonged usage, unexpected device failures were traced back to sensor interface instability. Engineers designed and integrated protection circuits for the input lines, resolving the issue permanently.
Mass Manufacturing: After successful validation, PCBs for both HHU and meter units were delivered for large-scale production.

Version 2: LoRaWAN-Based Scalable Smart Metering Ecosystem

Background and Motivation
Following the success of the RF-based system, the client sought to scale the deployment nationwide. However, the global chip shortage affected availability of the Si1062 platform. At the same time, LoRa (Long Range) technology emerged as a viable alternative with superior coverage, low power demands, and open protocol support.
Designing a Full-Stack LoRa Ecosystem: Phase wise Execution

Phase 1: Device Architecture

LoRa-Compatible Microcontroller: We transitioned to an STM32 wireless MCU with native LoRa support.
IM858 Modulation Protocol: Used for optimal range, low data rate, and enhanced robustness on the 868 MHz ISM band.
Supercapacitor Power Buffer: Integrated for energy spike handling and short-duration backup.
RF Tuning: Performed using spectrum analyzers to maximize signal fidelity and validate long-range communication.

Phase 2: Gateway Development

Rockchip RK3566: A highly cost-effective SoC was selected to build a custom LoRaWAN gateway PCB.
Semtech LoRa Shield: Used to enable RF transmission and reception.
Power and Connectivity: Gateways were powered via PoE and connected to the cloud using 4G SIM cards.

Phase 3: Server and Backend Stack

LoRaWAN Network Server: Built in-house to handle message routing using the MQTT protocol.
Application Layer: A PHP-based web application was developed for device provisioning, real-time monitoring, and user-level analytics.
Database and Geo-tagging: Support added for geo-location-based device management and data retrieval.

Phase 4: LoRa Repeater Deployment
After installing 400 devices, engineers identified black zones where meter data was not reaching the central server, despite power availability. The issue stemmed from poor 4G coverage, which prevented gateway communication. A newly introduced LoRa repeater technology was adopted:

These repeaters captured device signals and relayed them to nearby gateways without requiring SIM or internet.
As a result, gateway costs were reduced by over 50%, and previously unreachable areas became part of the network.

Business Value

The implementation of TechShlok’s solution led to significant results for Rahul Meters:

Extended Battery Life: The new smart meters successfully achieved a 10+ year battery life, sending data once a day, which significantly reduced maintenance costs.
Market Readiness: The cost-effective design allowed Rahul Meters to enter the smart meter market with a competitive edge, meeting industry standards.
Operational Efficiency: Reduced manpower needs for field data collection by over 80%.
Successful Deployment: Over 1,000 units were deployed in Ayodhya, Uttar Pradesh, marking a major step forward in modernizing the city’s water management infrastructure.

LoRaWAN-Based Smart Metering Solution