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PWM flow - nodes linking the websockets input to dashboard widgets |
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PWM dashboard displaying real-time data |
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3.7V 1000mAh Li-Po battery discharge characteristic |
Activities in electronics at Spacerowa Laboratories... hardware & software... prototyping & programming
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PWM flow - nodes linking the websockets input to dashboard widgets |
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PWM dashboard displaying real-time data |
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3.7V 1000mAh Li-Po battery discharge characteristic |
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Plant Water Monitor |
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Notice the 'favicon' in the browser page tab (click to enlarge) |
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Page: soil-moisture-sensor-v2.html |
🔳A couple of our recent projects involving sensors & WiFi, ( 'Solarometer' 📅13.10.2024 & 'Greenhouse Gas Sensors' 📅01.12.2024 ), have an integrated webserver hosting a webpage so that the sensor readings can be displayed on a client device, e.g., phone 🖁or computer💻, running a browser. Either HTTP or AJAX protocol was employed for the server-client connection.
A🪴'Plant Water Monitor' is a new project which will use a Websockets Server & Protocol instead. Websockets was briefly mentioned in the 'Solarometer' post. To recap, unlike HTTP or AJAX, Websockets provides real-time server/client communication over a continuously open full-duplex bidirectional connection 🔁, requiring no page refreshes or other requests; just the measurement data ( not the entire page ), are sent automatically, with minimal latency.
Testing Websockets has been successful. The Websockets server, ( programmed on the µ-controller in the 🪴Plant Water Monitor ), is assigned IP address 192.168.1.51 when it establishes a connection with our Wifi network router access point. Navigating to that address with a browser on a 🖁phone or 💻computer displays the page to see the data being updated.
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V1 viewed on a phone |
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V2 + WiFi signal level meter |
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V3 + popup notification |
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V4 + button & background image |
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Application window after navigating to this blog |
🔘 Until now the atmospheric "Particulate Matter Detector ( PMD )" project based on a 🪴Plantower 🗼PMS5003 particle concentration sensor and having a ⎚ display had been assembled on a solder-less 🍞 breadboard, ( see 📅16 June 2024 ), while awaiting further development.
A 'U ' cross-section 🖼frame, which functions as a stand, has been designed and produced on a 3-D printer 🖶 so that the PMD ( comprising PMS5003, colour display & µ-controller ) is now self-contained and can be easily moved to different locations.
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Front view |
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Rear view |
🔘In the post 📮dated 📅27 July 2023, about how a µ-controller and a smart phone🖁 App could be used to upload 🠝 configuration settings to modules based on AD9850 and AD9851 DDS chips in order to generate a frequency, it was briefly mentioned that a USB dongle and pc interface software was another method in use here. As that software has recently been updated it would now be a good time to give a description of that method also.
'DdsModTerm' user interface |
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(L) USB-SPI dongle (R) AD9851 DDS chip evaluation board on adaptor |
🔘 Carbon Dioxide, CO2, and Methane, CH4, are present in the atmosphere in part due to burning fossil fuels 🏭, and farming 🐂( particularly livestock ). They are potent 'greenhouse' gases as they have a significant impact on global warming, which drives climate change.
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Webpage opened in a smart phone's browser |
The concentration ( parts per million, ppm ) measurements📏 are updated in real-time 🕔, and can be quickly viewed on a mobile device's🖁 browser, saving time over logging in to cloud ☁ based repositories, if historical data are not required.
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Solar_Meter App user interface |
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Webpage displayed on a phone's browser |
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VISUVIR_Viewer App user interface |
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SpacerLabs Node-Red dashboard for the Solarometer |
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Node-Red workspace, (L) node palette, flow, (R) debug sidebar |
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Node-Red dashboard |
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Part of dashboard enlarged to show notification pop-up |
🔘Several previous posts have mentioned the 🔗Ubidots and 🔗Thingspeak IoT cloud ☁ platforms, conveniently accessed from a web-browser, that have been used with some of our sensor based projects to capture, visualise and analyse 💹 the sensor measurements. Two others, 'Arduino IoT Cloud' and 'Thingsboard', have been found and tried out in conjunction with the PMS5003 Particle Concentration Sensor; ( see 8 April & 16 June ). Setting up was quick and straightforward, following the typical process for such platforms of creating an IoT 'thing', assigning 'variables', associating a 'device', programming & connecting the device, & designing a 'dashboard'; our device is a "D1 Mini Esp32" micro-controller board.
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Example of Arduino IoT Cloud dashboard - desktop version |
An account was opened for the 30 day free trial period of the 🔗Thingsboard cloud 'Maker' version. There is a large selection of attractive widgets for the dashboard, sorted by various categories. For example, under the "Air 🜁 Quality" category there are numerous widget designs specifically for the measurement data relevant to air-quality. Some were chosen for the dashboard shown in the image below