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Continue Continue Privacy Notice Spaces Hit enter to search Help Online Help Keyboard Shortcuts Feed Builder What’s new Available Gadgets About Confluence Log in Weather Center Pages Blog Child pages Pages Home 2020 DFRobot Lead Acid Charger Browse pages Configure Space tools A t tachments (31) Page History People who can view Page Information Resolved comments View in Hierarchy View Source Export to PDF Export to Word Dashboard Skip to end of banner Jira links Go to start of banner Home Skip to end of metadata Created by Robert Nelson , last modified on Jan 02, 2020 Go to start of metadata Welcome to the Weather Center Members of Digi-Key’s Applications Engineering team began developing the Digi-Key Weather Center in a collaborative effort in February 2010. The Digi-Key Weather Center was placed on the roof of Digi-Key’s 600,000 square-foot facility in Thief River Falls, Minnesota in July 2010. The Digi-Key Weather Center was developed to demonstrate connectivity to customers by using products sold and supported by Digi-Key. Because Digi-Key is located in Northern Minnesota where the weather changes dramatically from summer to winter, it was determined to be the perfect location to demonstrate data communication with a weather station. The primary device used to develop the Digi-Key Weather Center was a ConnectPort X4 Zigbee to Ethernet gateway, which is equipped with access to iDigi from Digi International, one of Digi-Key’s 440\+ franchised suppliers. Additionally, Digi International Series 2 XBee modules programmed with Zigbee firmware were used for wireless communication to the device sensors and gateway. The initial sensor board was designed around a Microchip PIC18F14K22 microcontroller and a VTI temperature/pressure sensor, both of which are housed in a sealed Bud boxes with an IP65 rating. Solar panels from Parallax and sealed lead acid batteries from B.B. Battery and Panasonic were also used to develop the Digi-Key Weather Center. Digi-Key Applications Engineering team members Steve Dahl, Kevin Culkins, Shawn Rhen, Brandon Tougas, and Scott Raeker created the weather station, with each person assigned to different parts and stages of development. The project began with the design and construction of the structure that would hold the solar panel, control box and sensor nodes. Once the structure was completed, it was determined that sealed lead acid batteries and a charging circuit would be needed for power storage and distribution to the sensor nodes. The initial nodes developed for the project were a temperature/pressure sensor and a PWM controller enabled with a ZigBee module that relays the information to and from an Ethernet gateway. Next, python drivers were developed for the gateway, which relayed and managed the data to and from the sensor nodes. Finally, applications were developed for Android and Blackberry in order to present the data. External Interfaces Android Application Installation and setup Install Eclipse Download the Android SDK https://developer.android.com/index.html Add the plugin to Eclipse( https://developer.android.com/sdk/index.html ) Create a New Project File – new – Android Project Project name: Select build target – “Android x.x” Application name: Package name: Create Activity: Min SDK version: Select Finish Right click a file in the project Run as – Run Configuration Android Tab: Browse to select the current project Launch: select the one listed Target tab: Automatic – select manager Virtual Device – New Name: Target: SD Card: Skin: Hardware Create AVD Close the manager window Select the newly created AVD – Run In the AndroidManifest.xml file you can change the icon for the app In the string.xml file you can change the name of the app Loading the app on a phone PHONE: Under “Settings, Applications, Development”enable “USB debugging” Eclipse: Under “Run, Run Configurations” select the “target” tab. For Deployment Target Selection Mode select “Manual”. Download and install the USB drivers for your phone to your PC then run the android application. Gateway Digi's Software Packages DigiPython ESP '''New Project:''' New - iDigi Dia Project iDigi Dia Project Wizard Project name: xxx Use default location iDigi Dia Settings: Use default iDigi Dia Version: 1.3.8 Advanced project settings File name: xxx.yml Include iDigi Dia source code in project Python settings: Interpreter: Python 2.4.3 Remote Device: Use Current Remote Devices '''Run Project:''' iDigi gateway Modify and save the “xx.yml” file. Run it through the python.exe, in command prompt. “c:\idigi_dia\dia_pkg_1.3.8> c:\Python24\python.exe make.py demos\xxx\xxx.yml” Upload files for the gateway dia.zip dia.py Delete files off the gateway dia.pyr Reboot the gateway Telnet to the gateway using IP Address 192.168.1.xxx and port 23 then type python dia.py View the dia html page of the gateway by typing the following in a web browser 192.168.1.xxx/xxx Control Box The control box houses the the solar charging circuit board, battery, and the distribution of the power to the external sensors. 1st Gen Charger The battery charger board uses a Texas Instruments BQ2031 lead-acid fast-charge IC. Circuitry is based on TI's DV2031S2 lead-acid charger development board and configured for a 6-cell battery using the two-step voltage charging algorithm. Fast (bulk) charge voltage is set for 14.9V and maintenance (float) voltage is set for 13.7V. The input power for the charger is provided by three solar panels (each one outputs approximately 20V @ 0.5A under full sunlight conditions). ChargerBOMG1.pdf 3rd Gen Charger (picture coming soon) The latest revision of the charger implements a PIC30F6015 to control the output voltage of a LM2679 switching regulator circuit from National Semiconductor. The control software in the PIC results in a PWM output signal, which is delivered to the following circuit: The feedback signal is connected to the feedback pin of the LM2679. When the PWM signal is set to 0% duty, the PWM_LPF node is essentially driven to zero volts, which pulls the feedback node low through R20. This causes the regulator to respond by increasing it's output until the feedback pin reaches 1.21V. Conversely, if the PWM signal is set to 100% duty, the PWM_LPF node is driven to 3.3V, which pulls the feedback node high through R20. This causes the LM2679 to respond by decreasing the output until the feedback node reaches 1.21 volts. The output of the 10-bit resolution PWM allows ~4mV steps between 9.6V and 14V on the output of the LM2679. This provides very precise control of the voltage and current delivered to the 12v lead acid batteries. The control algorithm in the dsPIC30F6015 charges the batteries according to a 3A system limit to 13.8 volts, and tracks the peak output power point of the solar panels. It also measures the current being consumed by each of the other nodes, and can individually disable them in case of high current draw or low battery voltage conditions. Gen 2020 DFRobot Lead Acid Charger For the Weather Center 2020 season, we've upgraded the Lead Acid charger to an off the shelf solution from DFRobot DFR0580 , with 4 INA219 current sensors also from DFRobot SEN091 , to keep our Dual B&B Battery BP12-12-T2 topped off: 2020 DFRobot Lead Acid Charger Sensor Nodes In order to decrease development time for sensor nodes and Python drivers for the gateway, a common format for passing data has been created and standardized. This will also reduce the amount of data being passed between the Gateway and the XBee enabled sensor nodes. Gateway Character Key: request = "R" - All requests will lead with a NULL (0x00) operat...