Client

• Redesign the hardware with a 4-layer PCB for enhanced signal integrity and stability. 
  
• Implement a Real-Time Operating System (RTOS) to handle concurrent tasks like data acquisition, queuing, and MQTT communication. 
  
• Add custom circuitry for over-voltage protection, reverse polarity protection, and temperature-resilient operation.
  
• Build support for fuel-level acquisition using direct analog wire connections and integrate that with CAN-based OBD data using a single-channel CAN architecture.
  
• Redesign the enclosure and thermal layout to prevent SIM card failure in high-temperature environments.
  
• Debug and refactor existing firmware for modularity, efficiency, and long-term stability. 
  

Approach

• Prototype Design Review
  During our evaluation of the hardware, we discovered the prototype built with a 2-layer PCB suffered from runtime errors, inconsistent performance, and system failures when deployed in remote locations. This not only increased retrieval and maintenance costs but also undermined the client's production readiness. Furthermore, the prototype lacked robustness, scalability, and thermal stability needed for real-world use across BS4, BS5, and BS6 vehicle platforms.

• Hardware Redesign 
  
  
  (PCB Design)
  We upgraded the PCB from a 2-layer to a 4-layer architecture, enabling isolation of power and signal layers, which helped reduce interference and improve circuit reliability. We integrated automotive-grade protection components to handle input voltages of 100–120V and added reverse polarity protection.

• Power Circuit Design
  
  
  (Relay-based Control)We designed a robust DC-DC conversion system and relay-based switching architecture for stable signal operation in harsh environments. This allowed the same port to handle both OBD data and analog fuel data via separate input channels multiplexed through the CAN bus. 

• Software Optimization
  Transitioned the firmware to run on RTOS with independent task management for reading sensors, managing queues, and transmitting data. Implemented watchdogs, improved memory management, and filtered CAN messages to reduce processing load.

• Communication Protocol
  Enabled real-time data transmission using the MQTT protocol via the in-device SIM slot. This ensured lightweight, low-latency communication with the cloud backend even in low-bandwidth regions.

• Thermal Enclosure Redesign

(Device Enclosure)

The SIM modules in the earlier prototype were failing at 60°C ambient temperatures. We redesigned the enclosure to incorporate a heat sink and passive airflow to mitigate overheating and protect internal components.

• Validation And Manufacturing Support

                                                     

                                                                                                                                       (Device Installation and Testing)

After successful internal testing, the new device was deployed across 500+ trucks operating in varied climates. We also supported the client in production QA, assembly line setup, and component sourcing for scalable manufacturing.