Software development for controlling a grain seed treatment machine on Raspberry Pi with a touchscreen.

The company “Agrosepmash” is looking for an experienced developer to create software for managing a grain treatment machine. We are in the research and development (R&D) stage and plan to manufacture and sell this equipment. The hardware part of the treatment machine has already been developed and tested. We need to develop software to control the dosing system and other components via Raspberry Pi with a touchscreen display.

Project Goal:

To create a reliable and accurate control system for the grain treatment machine that ensures:

• Precise dosing of the treatment solution with accuracy maintained within ±3%.
• Automatic control of all system components.
• User-friendly and functional graphical user interface (GUI) on the touchscreen.
• Over-the-air software updates (OTA) via Wi-Fi.
• Support for multiple interface languages.
• System recovery after a power failure.

Hardware Part:

1. Peristaltic pump with stepper motor:

   • Controlled by Raspberry Pi Zero WH.
   • Pumps the treatment solution from the storage tank to the grain mixing channel.

2. Impulse flow meter FM-HL3012:

   • Used to measure liquid flow.
   • Provides feedback for accurate dosing.

3. Asynchronous motors:

   • Grain screw mixer:
     • Single-phase asynchronous motor at 230 V with a power of 1.5 kW.
   • Solution mixing pump in the tank:
     • Single-phase asynchronous motor at 230 V with a power of 0.37 kW.

4. Motor control:

   • Control of asynchronous motors is done through solid-state relays with opto-isolation.

5. Control system:

   • Raspberry Pi Zero WH with a 7" DSI Capacitive Touch Screen (800×480).
   • All equipment is provided for development and testing.

Tasks for the Developer:

1. Software development for Raspberry Pi:

   • Control of the peristaltic pump:

     • Implement control of the pump's stepper motor to ensure a specified flow rate of the solution in ml/min.
     • Use feedback from the FM-HL3012 flow meter to maintain dosing accuracy (±3%).
     • Develop a control algorithm (e.g., PID controller) to stabilize the liquid flow.

   • Control of asynchronous motors:

     • Implement the on/off control of the grain screw mixer motors and the solution mixing pump in the tank via solid-state relays with opto-isolation.
     • Ensure safe control of high-voltage equipment while adhering to safety measures.

2. Development of the graphical user interface (GUI):

   • Create an intuitive and functional interface on the Raspberry Pi touchscreen.

   • Implement the following features:

     • Start and stop all motors and pumps.

     • Input parameters for creating a grain treatment task:

       • Grain flow in t/h.
       • Required chemical consumption in l/t.

     • Automatic calculation of the required solution flow in ml/min.

     • Display of current parameters and system status in real-time.

     • Error handling and emergency situations with the ability to resume operation after a shutdown.

     • Support for different interface languages.

   • A description of the proposed interface is available.

3. Implementation of over-the-air software updates (OTA):

   • Ensure safe and reliable software updates via Wi-Fi.
   • Implement a notification system for updates and update status.

4. Documentation and code quality:

   • The software must be well documented.
     • Provide detailed instructions for installation, configuration, and operation.
     • Describe the system architecture and technologies used.
   • The code must be structured and contain comments to facilitate further support and development.
   • Use modular architecture to ensure the possibility of extending functionality.

5. Testing and debugging:

   • Conduct software testing on the provided equipment.
   • Ensure stable and reliable operation of the system in various modes.