Node-Red Dashboard for the PWM

🔘The "Node-Red " browser based visual programming environment has been used several times before. ( Use the search box to find out more about it and our previous related projects ). This time its dashboard feature is being used again in order to display in real-time the measurements being made by the "Plant Water Monitor - PWM" ( refer to last post 📅05.05.25).

A 'flow' was built-up by interconnecting nodes selected from the palette ( left sidebar ). The input to the flow is of course the measurements being sent by the PWM  'websockets' server. Fortunately the palette includes the node ( 'websocket in' ) to handle this ( highlighted in the image below ) ! 

PWM flow - nodes linking the websockets input to dashboard widgets

The entire websockets data payload is converted to JSON* string format, ( "{"name":"value" }" pairs ) and then output to the debug sidebar on the right. Basically, the other nodes separate out specific measurements from the string, ( battery voltage, battery charge state, time-stamp, moisture value, moisture level & version information ), which are then sent to the relevant widgets on the custom dashboard for viewing.

PWM dashboard displaying real-time data

Another flow & dashboard was also created consisting of just the battery voltage charge/discharge chart 📉widget and left running for 22 hours for the purpose of establishing the discharge characteristic of the 3.7V 1000mAh rechargeable Lithium-Ion-Polymer battery which powers the PWM.

3.7V 1000mAh Li-Po battery discharge characteristic

The value displayed on the primary dashboard for the 'percentage charge remaining' is based on the profile of that chart.🔲

* JSON = Java Script Object Notation.