Grain Storage Environment Control is a complete industrial control system, which supports automatic temperature and humidity balancing for grain storage facilities. The system provides automatic and manual control of the grain storage humidity, based on the grain temperature, environment temperature and humidity. The concept of using independent aeration controllers for each fan improves the system reliability and upon fail of one device, the system remains functional. The system setup consists of Intelligent weather station device, which measures air humidity and temperature, using factory calibrated digital humidity and temperature sensor and provides information for other devices in the network. The Aeration cControl Panel device controls single aeration fan. Temperature Processing Unit device is connected to the grain temperature sensors, providing the temperature measurement and processing operations and providing the information to additional integrated temperature controllers. The entire system is interconnected, using RS485 interface and custom designed time based multi-master protocol. The system supports integration to existing system gateway, providing cloud control and monitoring of the entire system.
Intelligent Weather Station
The Intelligent weather station device measures temperature and humidity, using factory calibrated digital temperature and humidity sensor. The implemented sensor supports self-heating element, providing possibility for runtime dehydration procedure. The device supports RS485 interface with implemented custom multi-master protocol, as well as 1WIRE interface for additional connection of remote temperature and rain measurement intelligent sensors. Supported is 2x16 character display for visualization of the measured parameters, as well as device states, firmware update state and dehydration procedure. Implemented is optional ETHERNET interface and integrated TCP/IP stack for additional communication to internet devices, allowing device control and firmware update from cloud service. Implemented SD card and FAT file system for storage of the device settings, storage of data LOG files and firmware update files. The device implements Real Time Clock and Calendar, supporting weekday and battery protected RAM storage. The 1WIRE interface is implemented as opto-isolated circuit, providing high reliability when connected to long external devices. The firmware is based on custom ported FreeRTOS and File system, providing great flexibility for real time operations and high reliability of the concept. The device implements custom created bootloader, supporting AES encrypted firmware update over RS485 and direct update from SD card. The flexible update procedure allows protection against unauthorized actions, allows flexible update on specific device and firmware version. The integrated multi-master RS485 protocol allows very flexible system configuration, including many Weather stations working in single system and automatic devices detection and synchronized communication, allows hot plug/unplug of devices and system recovery after single device fail.
✓ ETHERNET interface for internet connection, supporting 10/100BT. Implemented TCP/IP stack supporting dhcp addressing, TCP and UDP transport protocols;
✓ RS485 interface for system connection, supporting multi-master time based protocol;
✓ SD Card support for device storage, storing device configuration, measurement LOG files and firmware update information;
✓ Implemented I2C interface, with flexible speed control for connection to the temperature/humidity sensor;
✓ Implemented opto-isolated 1WIRE interface for optional connection to external intelligent temperature or rain sensors;
✓ Implemented 2x16 character display for visualization of the measured temperature and humidity, device procedures and firmware update;
✓ Implemented Real Time Clock and Calendar with weekday support;
✓ Implemented multi-master RS485 protocol, supporting flexible device arrangement in the network, based on device addressing, automatic detection of network nodes;
✓ Reliable firmware solution, implementing FreeRTOS Real Time Operating System, and flexible custom design communication and device drivers;
✓ Implementing FAT32 file system for SD card, used for file storage of settings, data LOG files and firmware update files;
✓ Implemented firmware update over RS485 and over SD card, based on secure AES128 firmware encryption;
✓ Implementing automatic dehydration procedure, based on the read values;
✓ Supports manual dehydration procedure;
Aeration Control Panel
The Aeration Control Panel device controls single or multiple aeration fans. The device can turn ON/OFF the aeration fans automatically, based on several conditions, or by direct commands in manual mode.
The device has graphical user interface, based on 2.8" color TFT display and resistive touch control. All buttons, graphical animations and status information widgets are completely custom designed and implemented in the used graphics library. Onboard serial flash memory holds all graphical resources and fonts. The graphical interface has multi-language support with implemented English language. Aeration fan status is visualized using custom created animation. Custom design driver is implemented for the used display.
Equipped with ETHERNET interface, the controller can be internet connected and controlled by cloud system, as well as possibility to make transparent connection to the other devices of the system and this way to be used as system gateway.The implemented opto-isolated RS485 interface is used for the system interconnection, reading the environmental temperature and humidity from Intelligent Weather Station, and grain temperature from dedicated temperature controller, using custom temperature protocol. The device is equipped with opto-isolated 1WIRE interface, allowing direct reading of 1WIRE temperature sensors.
The aeration fan is controlled, using 2 relays with configurable ON/OFF sequence. The aeration fan circuit is additionally monitored by AC line detection inputs, monitoring the input and fan voltage, capable of detecting AC and DC voltage in the range 12v to 250V. The fan thermal protection circuit is monitored, using contact detection input. Additional contact detection input allows cascade connection of several controlled aeration fans. All input active levels are adjustable trough menu.
Implemented SD card control and customized FAT32 file system allows file based device settings storage, as well as LOG file storage for fan status change and other additional events.The device integrates full featured real time clock and calendar with weekday support and has working hours aeration condition.
The controller has very flexible grain sensors selection for calculating grain temperature condition for aeration.
The controller firmware is based on real time operating system, ported for the used MCU architecture. The graphics library is modified to support the used LCD controller.Implemented is full featured custom designed bootloader, allowing firmware update over RS485 interface. The device bootloader is AES128 protected. Generating firmware update files using custom designed PC tool allows selection of the updated devices based on their serial number and the firmware version to update.
✓ Allowing control of single, or multiple aeration fans;
✓ Automatic control, based on pre-selected temperature and humidity conditions, manual control trough touch buttons;
✓ Graphical User Interface using 2.8" color TFT display and resistive touch input from the user;
✓ Onboard serial memory for holding all the graphical resources, picures and fonts;
✓ Custom designed animations for aeration fan status;
✓ Multi-language support with implemented default English language;
✓ Fully implemented ETHERNET interface and TCP/IP stack for internet connection, allowing internet remote control. Transparent internet to RS485 allows using the device as system gateway;
✓ Implemented opto-isolated RS485 interface as base system interconnection. Custom designed multi-master protocol allowing flexible device communication and automatic device detection in the network. Devices can be attached to the network in real time;
✓ Implemented opto-isolated 1WIRE interface, allowing direct reading of 1WIRE based temperature sensors;
✓ Aeration fan control, using electro-mechanical relays;
✓ Aeration fan voltage detection circuits, allowing detection of AC and DC voltage in the range 12V to250V;
✓ Aeration fan temperature detection circuit, allowing reliable temperature protection;
✓ Aeration fan status detection circuit, allowing cascade control of multiple aeration fans;
✓ Implemented SD card interface and FAT32 file system, allowing easy device configuration and storage of LOG files for all system events;
✓ Implemented Real Time Clock and Calendar with automatic weekday detection, adjustable from dedicated menu screen and RS485;
✓ Firmware design, based on custom ported Real Time Operating System;
✓ Flexible detection and selection of used grain sensors for grain temperature calculation;
✓ Custom designed bootloader, allowing secure firmware update over RS485 and direct update from SD card;
✓ AES128 encrypted firmware update, allowing flexible in-field update by device serial number and firmware version;
Firmware Update license generator tool
The license generator tool is used for generating the file images for firmware update of all devices in the system. The built-in bootloader of the devices needs additional license file, which to verify internally during the firmware update. The license file is generated per device and per firmware file. Checking the license file, only the device to which the firmware is licensed will allow the update. This feature is AES protected and prevents installing of unauthorized firmware and installing firmware on protected device. This feature is custom designed for the system, according to the customer's requirements
✓ Prevents firmware update with unauthorized firmware image;
✓ Prevents firmware update of unauthorized device with any image;
✓ Provides built-in integrity check of the firmware image before update;
✓ Can include many image files and update of may memories in the device;
✓ Can be Used by all devices in the system;
✓ Options for specific device behavior during update;
Provided services
✓ Providing technical requirements documentation and key components selection, based on the functional description;
✓ Development of the application level communication concept and the multi-master protocol, according to the system functional requirements;
✓ Schematic design of the Intelligent Weather Station and Aeration Control Panel deices, based on the selected key components, PDF export for customer's review;
✓ PCB design, pcb mechanical integration in the selected device enclosures;
✓ Production of prototypes, based on the in-field test results, order PCBs and components, organizing PCB and device assembly;
✓ Firmware design. Design of basic driver firmware modules, design of application level firmware, in circuit debug and testing. hardware and firmware optimization;
✓ Development of the License Generation Software tool software and used configuration connection approach;
✓ In-field tests for all devices;
✓ Design and providing of complete production and system integration documentation, application level protocol;
✓ Design and providing of user's guide documentation for the firmware update procedure and License generator software tool;