The process of designing and building an embedded systems project typically involves several key stages:
Project Planning and Requirements Definition: This stage involves clearly identifying the goals and requirements of the project. Important questions that must be answered include what the system is supposed to do, key functions and features it needs to have, performance requirements and constraints, cost and timelines. Thorough documentation of all technical and non-technical requirements is critical. User needs and market analysis may also be conducted depending on the nature of the project.
Hardware and Software Architecture Design: With a clear understanding of requirements, a system architecture is designed that outlines the high level hardware and software components needed to meet the goals. Key hardware components like the microcontroller, sensors, actuators etc are identified along with details like processing power required, memory needs, input/output interfaces etc. The overall software architecture in terms of modules and interfaces is also laid out. Factors like real-time constraints, memory usage, security etc guide the architecture design.
Component Selection: Based on the architectural design, suitable hardware and software components are selected that meet identified requirements within given cost and form factor constraints. For hardware, a microcontroller model from a manufacturer like Microchip, STMicroelectronics etc is chosen along with supporting ICs, connectors, circuit boards etc. For software, development tools, operating systems, libraries and frameworks are selected. Trade-offs between cost, performance, availability and other non-functional factors guide the selection process.
Hardware Design and PCB Layout: Detailed electronic circuit schematics are created showing all electrical connections between the selected hardware components. The PCB layout is then designed showing the physical placement of components and tracing of connections on the board within given form factor dimensions. Electrical rules are followed to avoid issues like interference. The design may be simulated before fabrication to test for errors. Gerber files are created for PCB fabrication.
Software Development: Actual software coding and logic implementation begins as per the modular architecture designed earlier. Programming is done in the chosen development language(s) using the selected compiler toolchain and libraries on a host computer. Firmware for the chosen microcontroller is mainly coded, along with any host based software needed. Important aspects covered include drivers, application logic, communication protocols, error handling, security etc. Testing frameworks may also be created.
System Integration and Testing: As hardware and software modules are completed, they are integrated into a working prototype system. Electrical and mechanical assembly and enclosure fabrication is done for the hardware. Firmware is programmed onto the microcontroller board. Host based software is deployed. Comprehensive testing is done to verify compliance with all requirements by simulating real world inputs and scenarios. Issues uncovered are debugged and fixed in an iterative manner.
Documentation and Validation: Along with code and schematics, overall system technical documentation is prepared covering architecture, deployment, maintenance, upgrading procedures etc. Validation and certification requirements if any are identified and fulfilled through rigorous compliance and field testing. User manuals, installation guides are created for post development guidance and support.
Production and Deployment: Feedback from validation is used to finalize the design for mass production. Manufacturing processes, quality control mechanisms are put in place and customized as per production volumes and quality standards. Supplier and logistic channels are established for fabrication, assembly and distribution of the product. Pilot and mass deployment strategies are planned and executed with end user training and support.
Maintenance and Improvement: Even after deployment, the development process is not complete. Feedback from field usage and changing requirements drive continuous improvement, enhancement and new version development via the same iterative lifecycle approach. Regular software/firmware upgrades and hardware refreshes keep the systems optimized over a product’s usable lifetime with continuous maintenance, issue resolution and evolution.
From conceptualization to deployment, embedded systems development is highly iterative involving multiple rounds of each stage – requirements analysis, architectural design, prototype development, testing, debugging and refinement until the final product is realized. Effective documentation, change and configuration management are key to sustaining quality through this process for successful realization of complex embedded electronics and Internet-of-Things products within given cost and time constraints. Careful planning, selection of tools, diligent testing and following best practices guide the development from start to finish.