Industrial Grad Custom PLC Design & Development

@tetianam8

⭐️⭐️⭐️⭐️⭐️ Hi, I’ve reviewed the specification carefully. This should be approached as a production-oriented industrial controller, not simply an STM32 development board. My preliminary recommendation would be an STM32-based main control system, with a separate ESP32-S3 only if the Wi-Fi/BLE/IoT requirements justify a dual-MCU architecture. This keeps machine control independent from cloud/wireless functions and makes the system easier to validate. I would cover: • 24 V industrial power and protection • 8 DI / 8 protected DO • 0–10 V / 4–20 mA analog I/O • RS-485/Modbus, Ethernet and CAN • EMC/ESD, surge/EFT and grounding strategy • Industrial isolation and PCB creepage/clearance • STM32 firmware framework, diagnostics, timers, PID and interlocks • DIN-rail and future expansion considerations Relevant experience: [YOUR REAL INDUSTRIAL/STM32 PROJECT + YOUR ROLE] I would first finalize the architecture and I/O implementation, then proceed through schematic → PCB → firmware → prototype bring-up and testing. Estimated initial development: 6–10 weeks, depending on the final I/O and communication requirements. Prototype PCB iterations: 2–3. I can provide the editable hardware/firmware sources and complete manufacturing documentation.

@yaroslavmark

Hi, I am an embedded hardware/firmware engineer experienced with STM32/ESP32 systems, 24 V industrial I/O, RS-485/Modbus, CAN, Ethernet, analog 0–10 V / 4–20 mA interfaces, FreeRTOS, and EMC/ESD-oriented PCB design. I have developed industrial controllers from architecture and schematic through PCB, firmware, bring-up, protection validation, and production documentation. Approach: ✅ I will define the system architecture first, including power, isolation strategy, I/O protection, analog front ends, communications, watchdog, diagnostics, and expansion interfaces. ✅ I would recommend a dual-MCU architecture: STM32 for deterministic PLC/control functions and ESP32-S3 for Wi-Fi/BLE/MQTT/OTA, with the control MCU remaining fully independent of IoT operation. ✅ I will design the 24 V DI/DO, 0–10 V and 4–20 mA channels with surge/EFT/ESD, reverse-polarity, short-circuit, grounding, creepage/clearance, and industrial EMC considerations. ✅ I will deliver schematics, PCB/manufacturing files, BOM, C/C++ firmware framework, Modbus communications, timers/PID/interlocks, test procedures, and prototype bring-up support. Questions: ✅ What current is required for each 24 V digital output? ✅ Which interfaces are mandatory for V1: Ethernet, RS-485, CAN, Wi-Fi/BLE? ✅ What accuracy and resolution are required for the 0–10 V and 4–20 mA channels? Best, Yaroslav

@MuhammadUzair16

Hi, I am an embedded systems engineer with over 16 years of experience developing production-oriented industrial controllers, remote I/O, motor-control electronics, gateways, and complete consumer and industrial products from concept through manufacturing. My work covers multilayer PCB design, STM32/ESP32 firmware, FreeRTOS, 24 V I/O, 0–10 V and 4–20 mA interfaces, Ethernet, RS-485/Modbus, CAN, power protection, EMC/ESD mitigation, bring-up, and production testing. For this controller, I recommend separating deterministic machine control from optional connectivity: an STM32G4/H7-class MCU would run all I/O, PID, timers, interlocks, alarms, watchdogs, and industrial communications, while an isolated ESP32-S3 subsystem handles Wi-Fi, BLE, MQTT, HTTPS, and OTA. This prevents cloud or wireless faults from affecting control. I would also assess modular CPU/I/O boards, isolated field interfaces, expansion provisions, diagnostics, and certification-oriented creepage, grounding, surge/EFT, and filtering from the outset. I can deliver the architecture, schematics, PCB, BOM, manufacturing package, reusable C/C++ firmware, test procedures, documentation, and prototype bring-up support using Altium or KiCad, STM32CubeIDE, and ESP-IDF. I normally expect two PCB iterations; prototype cost depends on layer count, enclosure, assembly quantity, and selected protection/isolation parts. Comparable projects cannot be shared publicly, but I can show relevant examples privately and explain my role, platforms, PCB, firmware, and EMC work. My bid covers the initial engineering milestone, and I am flexible once requirements and prototype quantities are confirmed. Please contact me to discuss details.

@danish2051

I am an Embedded Systems Engineer with hands-on experience in ESP32, STM32, Arduino, IoT solutions, PCB design, and industrial automation. I specialize in developing complete hardware and firmware solutions from concept to production. My experience includes sensor integration, wireless communication, data logging systems, Ethernet and Wi-Fi connectivity, MQTT communication, cloud integration, and custom PCB development. My expertise includes: • ESP32 Firmware Development • STM32 Firmware Development • Arduino Projects • PCB Design using Altium Designer • IoT Solutions (Wi-Fi, BLE, Ethernet, MQTT) • AWS IoT Integration • Sensor Integration and Calibration • Data Logging Systems • Industrial Automation Projects • Embedded Linux Development • Serial Communication (UART, RS485, Modbus) • I2C, SPI, CAN Bus Development • Product Prototyping and Testing my choice is stm32f407 mcu for this design

@Mahmoud00Ibrahim

Hello, I’m an Embedded Hardware & Software Engineer experienced in designing STM32/ESP32-based industrial and automotive controllers from schematic to production-ready PCB and firmware. I’ve worked with 24V power systems, CAN/CAN-FD, RS485/Modbus, protected I/O, DC/DC power supplies, ESD/EMI protection, reverse polarity, overvoltage and transient protection, with a strong focus on reliable hardware and noise-resistant PCB layout. For this PLC, I would recommend an STM32 as the main control MCU, with a separate ESP32-S3 only if the IoT requirements justify a dual-MCU architecture. Machine control would remain completely independent from Wi-Fi/cloud functions. I can handle: * System architecture & component selection * Complete schematic + PCB layout * 0–10V / 4–20mA I/O * Digital 24V I/O protection * RS485/Modbus, CAN, Ethernet * C/C++ firmware + FreeRTOS * Diagnostics, watchdogs, timers, PID & interlocks * Gerbers, BOM/MPN and manufacturing files * Prototype bring-up, testing and debugging I use Altium/KiCad and can deliver the complete editable hardware and firmware source files. I’d be happy to review the requirements and propose the architecture, development timeline and cost.

@mahmoudralizadeh

Hi, the core challenge is building a rugged PLC that can reliably handle 24 VDC industrial noise while providing flexible I/O and optional IoT connectivity. I have hands-on experience designing and building PLC and industrial control systems, including working prototypes. I also have a completed PLC unit currently available, so I can provide photos of the internal hardware and construction if you would like to review my previous work. I propose a dual-MCU architecture tailored to this requirement: an STM32H7 will handle deterministic machine control, analog scaling, Modbus RTU/TCP, and CAN-FD, while an ESP32-S3 will be dedicated to Wi-Fi/BLE, MQTT, and OTA functions. The two domains will be isolated so wireless activity cannot interfere with critical control loops. The firmware will use FreeRTOS with a modular ladder-style control API, hardware watchdogs, fault handling, and clear separation between control and communications tasks. On the hardware side, I will design protected and isolated 24 V inputs, 4–20 mA interfaces, robust power conversion, EMI filtering, and appropriate industrial protection. Deliverables will include the system architecture, complete schematic, PCB layout, Gerbers, BOM, firmware source code, and a structured prototype bring-up plan with support during initial hardware testing. Best regards, Mahmoudreza

@nichitav7

Hello, I can develop this project from system architecture through schematic/PCB design, firmware, prototype bring-up, and manufacturing support. I have experience with industrial controllers, motor-control boards, sensor gateways, STM32/ESP32 systems, 24V I/O, RS-485/Modbus, CAN, Ethernet, analog interfaces, watchdogs, and industrial protection circuits. For this project, I recommend an STM32 as the main real-time control MCU and, if Wi-Fi/BLE/cloud functions are required, a separate ESP32-S3 for IoT. This keeps machine-control functions independent from networking and OTA tasks. I can design the 24V digital I/O, 0–10V/4–20mA analog interfaces, RS-485, CAN/CAN-FD, Ethernet, protected 24V power supply, ESD/EFT/surge protection, RTC, diagnostics, and expansion interface. Firmware can include FreeRTOS, Modbus, timers, counters, PID, interlocks, alarms, diagnostics, and reusable control logic. I use Altium Designer, STM32CubeIDE, and ESP-IDF. I can provide all editable source files, BOM, Gerbers, firmware, test procedures, and prototype/manufacturing support. I would normally expect about 2 PCB prototype iterations for a production-oriented design of this complexity.

@sidratulm20

Are you looking for an experienced Embedded Systems and Industrial Electronics Engineer to develop a production-oriented custom PLC/controller from architecture through PCB, firmware, prototype bring-up, and testing? I can work on the complete system with particular attention to 24 VDC industrial I/O, analog 0–10 V / 4–20 mA interfaces, RS-485/Modbus, Ethernet, CAN, EMC/ESD protection, diagnostics, and reliable machine-control operation. I have experience with embedded systems, STM32/ESP32, C/C++, PCB design, industrial I/O, power protection, communication interfaces, and manufacturing-ready electronics documentation Deliverables System architecture and detailed block diagram MCU and communication architecture recommendation Single-MCU vs dual-MCU analysis Complete electrical schematic 24 VDC protected digital input/output design 0–10 V and 4–20 mA analog interfaces RS-485/Modbus, Ethernet, CAN/CAN-FD and service interfaces as required Power supply, reverse-polarity, surge, ESD, EFT and overcurrent protection EMC-conscious grounding, isolation, filtering, creepage and clearance design Industrial PCB layout and design-rule review Complete BOM with manufacturer part numbers Development approach I would first freeze the system architecture and electrical requirements, then develop the schematic and protection strategy before PCB layout. After prototype fabrication,

@xintian923

Having worked as an agile and versatile Embedded Systems Engineer for several years, I am well-positioned to tackle your industrial PLC design project. I have experience with all aspects of hardware and software development that are required - from PCB design and firmware development to Windows and mobile applications. This means that there will be no gaps in communication or understanding between different parts of the project. In my previous work, I have designed PCBs using Altium for a range of microcontrollers including ESP32, nRF52, STM32. I am well-versed in the hardware requirements you mentioned (input/output isolation, surge protection, EMI/EMC filtering et al). On the firmware side, I've extensively used C/C++ for complex control functions like PID Control in addition to simple ones like digital inputs and outputs. Moreover, my experience in IoT devices can help us make an informed decision regarding a separate communication processor versus a single MCU architecture for optional IoT functions. Safety and reliability is where I draw the line between IoT and machine-control functions; both will work independently without compromising each other's performance. Together, we can build a reliable and scalable product that meets all your needs. (Misses off)

@shivkantverma

Hi, Greetings! I am interested in working on your project. Could you please share the design details and technical requirements so we can discuss the project scope and key parameters in detail? I look forward to working with you. Thank you! Shivkant

@hamzaePCB

Before starting the PCB design, I would first review the proposed architecture and separate the industrial control hardware from the optional IoT/connectivity section. For the hardware, I would consider an STM32-class MCU for the main control section, with an ESP32-S3 as an optional separate connectivity processor for Wi-Fi/BLE if required. My scope would be focused specifically on the electronic hardware and PCB design, rather than development of the complete PLC firmware/software platform. I can handle: • Hardware architecture and component selection • Complete schematic design • 24 V digital input/output interface circuitry • 0–10 V / 4–20 mA analog interfaces • RS-485/CAN/Ethernet hardware interfaces as required • Power supply, isolation and protection circuitry • ESD/surge protection and PCB grounding strategy • Multilayer PCB layout • Gerber, BOM, Pick & Place and manufacturing files • Hardware bring-up/debugging support Before schematic design, I would confirm the required I/O isolation, output load/current ratings, analog accuracy, communication interfaces, protection requirements and DIN-rail enclosure constraints. If you are open to assigning the hardware/PCB development as a separate scope, I would be interested in working on that part of the project.

@mcollinscalz

Hello, Designing a production-ready industrial PLC requires bulletproof hardware isolation, rigorous EMC/ESD protection, and deterministic control logic. As an Embedded Systems & Industrial Electronics Engineer, I can deliver a manufacturable, DIN-rail-compatible controller built for harsh industrial environments. Architectural Recommendation & Strategy: Architecture: I recommend a dual-MCU setup—an STM32F4/G4 dedicated purely to real-time execution (FreeRTOS, 1ms scan loops, I/O processing, Modbus/CAN) paired with an ESP32-S3 isolated over UART/SPI for MQTT, web UI, and OTA updates. This guarantees zero cloud latency impacts machine logic. Hardware Protection: Optocoupler/digital isolators on 24V I/O, TVS diodes, Schottky reverse-polarity protection, PTC fuses, and surge filtering designed to IEC 61000-4 standards (ESD/EFT). Firmware Framework: Clean C/C++ supporting non-blocking TON/TOF timers, PID loops, analog scaling, and Modbus RTU/TCP stacks. Deliverables & Tools: Hardware: KiCad/Altium schematics, 4-layer PCB layout, Gerbers, CPL/BOM with active part numbers, and DIN-rail enclosure fitment (single PCB recommended for initial cost efficiency). Firmware: Full C/C++ source code, FreeRTOS setup, test scripts, and bring-up documentation. Timeline & Terms: Tools: Altium / STM32CubeIDE / ESP-IDF Timeline: ~6–8 weeks (2 PCB iterations expected) Let's discuss your timeline and cost expectations. Best regards,

@bilalh585

Are you looking for a production-oriented Industrial PLC/Controller with reliable hardware, robust firmware, industrial protection, and future scalability? I can help design and develop a custom industrial controller suitable for real-world industrial environments. Based on your requirements, I can support STM32/ESP32 architectures, 24V digital I/O, 0–10V and 4–20mA analog interfaces, RS-485/Modbus RTU, Modbus TCP, Ethernet, CAN/CAN-FD, Wi-Fi/BLE connectivity, watchdogs, diagnostics, RTC, expansion interfaces, and industrial-grade EMC/ESD protection. I can also review the specifications and recommend the most suitable single-MCU or dual-MCU architecture. I have experience in Embedded Systems, Industrial Electronics, PCB Design, STM32/ESP32 development, industrial communication protocols, and custom controller development for automation and machine-control applications. Deliverables System architecture & block diagram Component selection & BOM Complete schematic design Multi-layer PCB layout Gerber & manufacturing files Firmware source code (C/C++) Testing, debugging & documentation support Why choose me? Strong CAD/PCB design background Experience with embedded firmware development Focus on reliability and manufacturability Industrial communication and I/O experience Attention to protection, isolation, and noise immunity Long-term support during prototyping and testing Best regards, Bilal

@alfatrade2

I have experience in industrial automation design: equipping a profile cutting section with motorized positioning and feedback, developing firmware for microcontrollers in C/C++. For your PLC, I recommend an STM32 as the base with a separate ESP32 for IoT—this will ensure control reliability and the isolation of critical functions. How do you plan to test EMC resilience in industrial interference conditions?

@hamzazayyad

Hi, For the PLC design, I can make your life much easier on getting the first working prototype. I already have industrial controller designs I can build on, and long experience in industrial automation with Siemens and Delta PLCs — so I can build a PLC in hardware and firmware that follows the same architecture as a professional design. Reply here and let's discuss your project in detail. Best regards, Hamza Electrical and Control Engineer

@hayat38402

Hi, how are you doing? I went through your project description and I can help you in your project. your project requirements perfectly match my expertise. We are a team of Electrical and Electronics engineers, we have successfully completed 1000+ Projects for multiple regular clients from OMAN, UK, USA, Australia, Canada, France, Germany, Lebanon and many other countries. We are providing our services in following areas:  Antenna Design (CST, HFSS)  Embedded C Programming.  VHDL/Verilog, Quartus/Vivado, LabVIEW/ Multisim/PSPICE/VLSI  MATLAB/SIMULINK  Network Simulator NS2/NS3  Microcontroller like Arduino, Raspberry Pi, FPGA, AVR, PIC, STM32 and ESP32.  IDEs like Keil MDK V5, ATmel studio and MPLab XC8.  PLCs / SCADA  PCB Designing Proteus, Eagle, KiCAD and Altium  IOT Technologies like Ethernet, GSM GPRS.  HTTP Restful APIs connection for IOT Communications. Also, we have good command over report writing, I can show you many samples of our previous reports. Kindly consider us for your project and text me so that we can further discuss specifically about your project's main goals and requirements.

@SkillCrafts

I noticed your need for a robust custom industrial PLC, and my recent project involving a high-reliability process controller for automated manufacturing, which also required custom PCB design and stringent industrial certifications, aligns perfectly with your requirements. I understand the critical distinction between hobbyist boards and production-ready industrial solutions. My approach would involve leveraging an ARM Cortex-M microcontroller for its processing power and peripheral set, integrated with robust industrial-grade I/O drivers and transient suppression. I'll design a multi-layer PCB optimized for signal integrity and EMC compliance, utilizing Altium Designer. Firmware development will be in C, focusing on real-time operating systems (RTOS) for deterministic task management and implementing industry-standard communication protocols like Modbus TCP/IP or EtherNet/IP. Extensive unit and integration testing, along with EMC/ESD pre-compliance testing, will be integral. Could you elaborate on the specific environmental factors and expected lifecycle for this controller? What are your initial thoughts on the primary communication protocol requirements? I'm available for a brief call to discuss how my expertise can translate into a successful, manufacturable solution for your project.

@WaddahJanajreh93

Hi, I am from Palestine and currently live and work in Spain at Amos, where I am developing a CO₂ machine using an industrial PLC based on Raspberry Pi. My work covers hardware design, firmware, schematics, and Linux/Python development. I also created the machine’s electrical wiring diagrams. I work with STM32 and ESP32 platforms and use Altium and KiCad for schematic and PCB design. I have also designed a similar controller project for a metal detector using W5500 for Ethernet connectivity. We can discuss that approach and evaluate whether it would suit your controller. Regarding the budget, $250–750 is very low for the full scope described. This is a substantial project covering industrial hardware, PCB design, firmware, documentation, and prototype debugging support. We would need to agree on a realistic budget or divide development into separately priced milestones. I also speak Arabic, so we can communicate in Arabic if that is easier for you. I would be happy to discuss your requirements and define the architecture, development time, and cost.

@Aaleen110

The risk here is that the custom PLC hardware design, particularly the EMC/ESD protection and ensuring manufacturability at the component level, might not integrate cleanly with the embedded firmware development and the specific industrial communication protocols you need, so I'd start by creating a block diagram and schematics for the core analog and digital I/O sections, also verifying component selection for robustness against industrial noise. Then I'd move to the microcontroller selection and base firmware for that, getting the basic GPIO and interrupt handling working before the board is even fabricated. This order ensures the firmware foundation is solid. I would build the prototype on a breadboard or perfboard initially for the I/O and communication interfaces using off-the-shelf modules where possible, so you can see the core logic functioning quickly, before committing to the custom PCB. I build Embedded Systems and Firmware Development. Preferred Freelancer here, 5.0 over 10 reviews, no missed deadline and nothing over an agreed price yet. Do you have a specific microcontroller family in mind for this controller, or should I select one based on I/O requirements and cost? I need the detailed list of required digital and analog I/O specifications.