Industrial RO Plant Controller – Complete PCB & Electronics Design
Budget / Salary₹1,500–12,500
TypeFreelance project
LocationRemote
Posted3 hours ago
PCB Design & Engineering for HydroNest RO Plant Controller
1. Project Objective
We are developing a professional controller PCB for commercial/light-commercial RO water treatment plants under HydroNest India.
The objective is to take our existing functional requirements, selected components/modules and control logic, and have an experienced electronics engineer design, optimize and finalize the complete electronic controller.
We are not looking only for PCB layout work. The engineer should be capable of taking the requirements at a system level and developing the complete electrical design, schematic, component selection/optimization and production-ready PCB.
⸻
2. What We Will Provide
We will provide:
* RO plant operating requirements and sequence
* List of pumps, solenoid valves, sensors, switches and other field devices
* Required inputs and outputs
* Existing/ preferred components and modules
* ESP32-based controller/HMI requirements
* Communication requirements
* Existing firmware/control logic where applicable
* Electrical voltage/current requirements wherever known
* Physical/enclosure constraints wherever applicable
The engineer should review the provided components and recommend better alternatives wherever required for reliability, availability, cost or manufacturability.
⸻
3. Controller Requirements
The PCB will act as the main electronic controller for the RO plant and should be designed around an ESP32-based control system.
The controller should support, as applicable:
Digital Inputs
* Float/level switches
* Tank level inputs
* Pressure switches
* Plant fault inputs
* Other ON/OFF field sensors
Sensor Inputs
* Flow sensors
* TDS/EC or water-quality sensors where required
* Other analog/digital sensors required by the final system
Outputs
The controller should be capable of controlling:
* High-pressure pump
* Raw-water/feed pump
* Solenoid valves
* Flush valves
* Dosing systems where applicable
* Other RO plant actuators
The exact output architecture should be determined by the engineer based on the loads.
Where pumps or high-power equipment cannot be driven directly, the PCB should provide the appropriate relay/contactor/driver interface.
⸻
4. Power Supply
The controller is intended to operate in an industrial RO plant environment with a 24V DC control supply / field environment.
The engineer should design the required power architecture, including appropriate:
* 24V input protection
* Fuse/protection
* Reverse-polarity protection
* Surge/transient protection
* DC-DC regulation
* 5V and/or 3.3V rails
* ESP32 power supply
* Protection for sensitive electronics
The design should account for the electrically noisy environment created by pumps, solenoid valves, contactors and other inductive loads.
⸻
5. Relay / Output Protection
All inductive outputs should be designed appropriately.
The engineer should determine and implement the required:
* Flyback protection
* TVS/surge suppression
* MOSFET/driver stages where appropriate
* Relay driver circuits
* Isolation where appropriate
* Protection between field wiring and the ESP32
The ESP32 GPIOs must not be exposed directly to unsuitable field voltages or loads.
⸻
6. HMI & Communication
The system will communicate with an ESP32-S3 based HMI/display controller.
The current system uses an ESP32-S3 7-inch touchscreen HMI and wireless communication is being explored/implemented using ESP-NOW/Wi-Fi.
The PCB engineer should design the controller architecture so that communication with the HMI is reliable and practical.
The engineer should also recommend the most appropriate physical communication/interface architecture if changes are required.
⸻
7. Cellular / Connectivity
A cellular communication module such as the A7672S 4G module is being considered for remote connectivity.
The engineer should evaluate the best way to integrate this into the overall controller architecture, including:
* UART communication
* Power requirements
* SIM/network requirements
* Antenna connection
* Power supply/current requirements
* GPIO requirements
* Electrical protection
If integrating the cellular modem directly onto the main PCB is not advisable, the engineer may recommend a modular approach.
⸻
8. Industrial Reliability
This is intended to be a real commercial RO plant controller, not a hobby/Arduino development board.
The PCB should therefore be designed with consideration for:
* Electrical noise
* Inductive loads
* Voltage transients
* Field wiring
* Proper grounding
* Signal integrity
* Separation of noisy and sensitive circuits
* Appropriate creepage/clearance
* Connector reliability
* Serviceability
* Long-term operation
* Manufacturability
The engineer should identify potential reliability issues in our initial component selections and propose improvements.
⸻
9. PCB Design
The engineer will be responsible for the complete PCB design, including:
1. System architecture
2. Circuit design
3. Schematic
4. Component selection/review
5. PCB layout
6. Routing
7. Power and ground design
8. Input/output protection
9. Connector placement
10. Design for manufacturing
11. Design for assembly
12. Final design review
The PCB should be designed for practical production rather than only prototype operation.
⸻
10. Modular / Future Expansion
Where practical, the design should allow future expansion of the controller.
Potential future requirements include:
* Additional sensors
* Additional outputs
* Different RO plant capacities
* Additional communication interfaces
* Remote monitoring
* Additional automation functions
The engineer should recommend a sensible architecture that allows expansion without unnecessarily increasing PCB cost and complexity.
⸻
11. Required Deliverables
The final project should include:
* Complete electrical schematic
* PCB design/layout
* Complete BOM
* Component part numbers
* Gerber files
* Drill files
* Pick-and-place/CPL files if applicable
* Assembly drawings
* PCB fabrication files
* PCB 3D model/render
* Source design files
* Design documentation
* Recommended PCB manufacturer specifications
* Recommended PCB assembly specifications
All source files should be provided to HydroNest India.
⸻
12. Prototype & Testing
The engineer should support the first prototype build and assist with debugging any hardware issues identified during testing.
The expectation is:
Requirements → Engineering design → Schematic → Review → PCB → Prototype → Testing → Corrections → Final production files
The final design should be suitable for moving toward production after successful prototype testing.
⸻
13. Important Requirement
We are looking for an engineer who can take ownership of the electronics engineering, rather than simply following a provided schematic.
We will explain what the RO plant needs to do and provide our existing component selections and requirements.
The engineer is expected to:
* Review our selections
* Identify problems
* Suggest improvements
* Select suitable supporting components
* Design the complete circuits
* Optimize the design
* Create the PCB
* Ensure the final design is reliable and manufacturable
The engineer should ask questions where requirements are unclear rather than making assumptions.
⸻
14. Ideal Freelancer
Experience preferred in:
* Industrial control PCBs
* ESP32 / ESP32-S3
* 24V industrial electronics
* Relay and MOSFET control
* Pumps and solenoid valves
* Sensor interfaces
* RS485/UART
* Wi-Fi/ESP-NOW
* Cellular modules such as SIMCom A76xx series
* Power supply design
* PCB manufacturing
* EMI/noise protection
* Water-treatment or similar industrial automation systems
Experience with industrial automation/control panels is strongly preferred over purely hobby/Arduino PCB experience.
⸻
15. Important Note
We already have a working understanding of the required functionality and some preferred components.
However, we do not want the freelancer to blindly convert our component list into a PCB.
We want an experienced engineer who can take the requirements, review the proposed architecture and deliver a professional, optimized and production-ready controller PCB.
1. Project Objective
We are developing a professional controller PCB for commercial/light-commercial RO water treatment plants under HydroNest India.
The objective is to take our existing functional requirements, selected components/modules and control logic, and have an experienced electronics engineer design, optimize and finalize the complete electronic controller.
We are not looking only for PCB layout work. The engineer should be capable of taking the requirements at a system level and developing the complete electrical design, schematic, component selection/optimization and production-ready PCB.
⸻
2. What We Will Provide
We will provide:
* RO plant operating requirements and sequence
* List of pumps, solenoid valves, sensors, switches and other field devices
* Required inputs and outputs
* Existing/ preferred components and modules
* ESP32-based controller/HMI requirements
* Communication requirements
* Existing firmware/control logic where applicable
* Electrical voltage/current requirements wherever known
* Physical/enclosure constraints wherever applicable
The engineer should review the provided components and recommend better alternatives wherever required for reliability, availability, cost or manufacturability.
⸻
3. Controller Requirements
The PCB will act as the main electronic controller for the RO plant and should be designed around an ESP32-based control system.
The controller should support, as applicable:
Digital Inputs
* Float/level switches
* Tank level inputs
* Pressure switches
* Plant fault inputs
* Other ON/OFF field sensors
Sensor Inputs
* Flow sensors
* TDS/EC or water-quality sensors where required
* Other analog/digital sensors required by the final system
Outputs
The controller should be capable of controlling:
* High-pressure pump
* Raw-water/feed pump
* Solenoid valves
* Flush valves
* Dosing systems where applicable
* Other RO plant actuators
The exact output architecture should be determined by the engineer based on the loads.
Where pumps or high-power equipment cannot be driven directly, the PCB should provide the appropriate relay/contactor/driver interface.
⸻
4. Power Supply
The controller is intended to operate in an industrial RO plant environment with a 24V DC control supply / field environment.
The engineer should design the required power architecture, including appropriate:
* 24V input protection
* Fuse/protection
* Reverse-polarity protection
* Surge/transient protection
* DC-DC regulation
* 5V and/or 3.3V rails
* ESP32 power supply
* Protection for sensitive electronics
The design should account for the electrically noisy environment created by pumps, solenoid valves, contactors and other inductive loads.
⸻
5. Relay / Output Protection
All inductive outputs should be designed appropriately.
The engineer should determine and implement the required:
* Flyback protection
* TVS/surge suppression
* MOSFET/driver stages where appropriate
* Relay driver circuits
* Isolation where appropriate
* Protection between field wiring and the ESP32
The ESP32 GPIOs must not be exposed directly to unsuitable field voltages or loads.
⸻
6. HMI & Communication
The system will communicate with an ESP32-S3 based HMI/display controller.
The current system uses an ESP32-S3 7-inch touchscreen HMI and wireless communication is being explored/implemented using ESP-NOW/Wi-Fi.
The PCB engineer should design the controller architecture so that communication with the HMI is reliable and practical.
The engineer should also recommend the most appropriate physical communication/interface architecture if changes are required.
⸻
7. Cellular / Connectivity
A cellular communication module such as the A7672S 4G module is being considered for remote connectivity.
The engineer should evaluate the best way to integrate this into the overall controller architecture, including:
* UART communication
* Power requirements
* SIM/network requirements
* Antenna connection
* Power supply/current requirements
* GPIO requirements
* Electrical protection
If integrating the cellular modem directly onto the main PCB is not advisable, the engineer may recommend a modular approach.
⸻
8. Industrial Reliability
This is intended to be a real commercial RO plant controller, not a hobby/Arduino development board.
The PCB should therefore be designed with consideration for:
* Electrical noise
* Inductive loads
* Voltage transients
* Field wiring
* Proper grounding
* Signal integrity
* Separation of noisy and sensitive circuits
* Appropriate creepage/clearance
* Connector reliability
* Serviceability
* Long-term operation
* Manufacturability
The engineer should identify potential reliability issues in our initial component selections and propose improvements.
⸻
9. PCB Design
The engineer will be responsible for the complete PCB design, including:
1. System architecture
2. Circuit design
3. Schematic
4. Component selection/review
5. PCB layout
6. Routing
7. Power and ground design
8. Input/output protection
9. Connector placement
10. Design for manufacturing
11. Design for assembly
12. Final design review
The PCB should be designed for practical production rather than only prototype operation.
⸻
10. Modular / Future Expansion
Where practical, the design should allow future expansion of the controller.
Potential future requirements include:
* Additional sensors
* Additional outputs
* Different RO plant capacities
* Additional communication interfaces
* Remote monitoring
* Additional automation functions
The engineer should recommend a sensible architecture that allows expansion without unnecessarily increasing PCB cost and complexity.
⸻
11. Required Deliverables
The final project should include:
* Complete electrical schematic
* PCB design/layout
* Complete BOM
* Component part numbers
* Gerber files
* Drill files
* Pick-and-place/CPL files if applicable
* Assembly drawings
* PCB fabrication files
* PCB 3D model/render
* Source design files
* Design documentation
* Recommended PCB manufacturer specifications
* Recommended PCB assembly specifications
All source files should be provided to HydroNest India.
⸻
12. Prototype & Testing
The engineer should support the first prototype build and assist with debugging any hardware issues identified during testing.
The expectation is:
Requirements → Engineering design → Schematic → Review → PCB → Prototype → Testing → Corrections → Final production files
The final design should be suitable for moving toward production after successful prototype testing.
⸻
13. Important Requirement
We are looking for an engineer who can take ownership of the electronics engineering, rather than simply following a provided schematic.
We will explain what the RO plant needs to do and provide our existing component selections and requirements.
The engineer is expected to:
* Review our selections
* Identify problems
* Suggest improvements
* Select suitable supporting components
* Design the complete circuits
* Optimize the design
* Create the PCB
* Ensure the final design is reliable and manufacturable
The engineer should ask questions where requirements are unclear rather than making assumptions.
⸻
14. Ideal Freelancer
Experience preferred in:
* Industrial control PCBs
* ESP32 / ESP32-S3
* 24V industrial electronics
* Relay and MOSFET control
* Pumps and solenoid valves
* Sensor interfaces
* RS485/UART
* Wi-Fi/ESP-NOW
* Cellular modules such as SIMCom A76xx series
* Power supply design
* PCB manufacturing
* EMI/noise protection
* Water-treatment or similar industrial automation systems
Experience with industrial automation/control panels is strongly preferred over purely hobby/Arduino PCB experience.
⸻
15. Important Note
We already have a working understanding of the required functionality and some preferred components.
However, we do not want the freelancer to blindly convert our component list into a PCB.
We want an experienced engineer who can take the requirements, review the proposed architecture and deliver a professional, optimized and production-ready controller PCB.
Apply on Freelancer →
Project sourced from Freelancer.com. Applications happen directly on the original platform — we never collect your data.