Add Numeric Display Widget

Field 1 on this channel is a counter value that demonstrates the device is live and incrementing measurements. Showing the latest value of the counter on the channel view provides a quick update on the activity of the sensor. You can add aNumeric Display Widget为你的频道using theAdd Widgetsbutton in your private channel view. Note that you need data in your channel to see the field value on a numeric display widget.

Add Channel Location Map

You can store location information for a channel and for individual updates to the channel data. For this example, first add a channel location map, which is different from the feed data location information. Select theChannel Settingstab on your channel view.

SelectShow Channel Locationand enter theLatitudeandLongitudeinformation for your channel location.

ClickSave Channelto update the settings.

Now both your private and public channel views include the channel map.

Add a Two-Series Plot to Channel View

MATLAB可视化提供更多的控制analysis and plots compared to the default ThingSpeak plots shown in your channel view. Certain license types also allow automatic updates of the visualizations. You can use both time and threshold filtering to improve the data visualization. For this example, visualize the relationship between temperature and soil moisture. Start by clicking theMATLAB Visualizationbutton on your channel view.

Select a custom code template. Enter the code below into the MATLAB code window. Because the data of interest is from a previous experiment, use time filtering to read the older data from the channel. Set the start and end times withdatetime. Then read the data into a timetable usingthingSpeakRead.

startTime = datetime(2019,8,23,09,15,00); endTime= startTime+ days(2); sensorData = thingSpeakRead(876466,'Location',1,'dateRange',[startTime endTime],...'location',1,'outputformat','timetable');

The temperature data in column three has some bad measurements that must be filtered out before plotting. Delete all rows where the temperature reading is larger than 100.

sensorData(sensorData{:,3}>100,:)=[];

Now complete the plot. Useholdto make sure the plots are in the same figure andyyaxisto plot the soil moisture on the right axis. Add aylabelon each side for clarity, and set the scale withylim.

plot (sensorData.Timestamps,sensorData.TemperatureF) ylabel('^0F'); hold;

Current plot held

yyaxisrightplot(sensorData.Timestamps,sensorData.SoilMoisture); ylabel('Soil Conductivity'); ylim([700 900]); holdoff;

The soil moisture probe measures conductivity in the soil, so wetter, more conductive measurements have lower values on the plot. The plot shows that cooler temperatures are correlated with wetter soil.

Visualize Measurements with Location Data on the Channel View

For this channel, the prototype sends position data along with the sensor measurements. One application is to survey a large area with temperature and moisture measurements and visualize the data with location.

As in the previous example, add a new MATLAB visualization using the button on your channel view. Read the most recent points withthingSpeakRead, and plot the location data withgoescatter. Usegeobasemapto select satelite map data.

mapData = thingSpeakRead(876466,'ReadKey','R14RSDIMCQHDW1A8','Location',...1,'numpoints',37,'location',1,'outputformat','timetable'); geoscatter(mapData.Latitude,mapData.Longitude,'r'); geobasemap('satellite');

The map provides a good visualization of the positions. Include temperature and moisture data in the map to improve the visualization. When the measurement device is moved from one location to another it can make an inaccurate moisture measurement before the probe is replaced in the ground. Remove any data with values less than 500 in the soil moisture data in column two. Then rescale the data for visibility. Add the moisture data to thegoescatterfunction to determine the size of the circles, and the temperature data to determine the color. Use the‘filled’option to fill the circles.

mapData(mapData{:,2}<500,:)=[]; mapData.SoilMoisture=mapData.SoilMoisture-min(mapData.SoilMoisture)+1; geoscatter(mapData.Latitude,mapData.Longitude,mapData.SoilMoisture,mapData.TemperatureF,'filled'); geobasemap('satellite');

The subtle effect of warmer locations in front of the building leads to some smaller circles indicating drier soil, except on the right where the sprinklers had just finished.

You can add saved visualizations to the public and private views of your channel. InDisplay Settings, use the plus sign next toAdd/Edit this Visualization to a Channelto expand the channels list.

Select the check box that corresponds to the channel you want to add the visualization to. To add private visualizations, selectPrivate View. To share the URL and add the visualization to thePublic View, clickCreate a public URL. To update your selections, clickSave Display Settings.