Sample Application to stream data to Plotly using Spark Core. The application stream temperature value from DHT22 Sensor to Plotly. To use this application create a Plotly account, download the source and open it in Spark Editor and replace the tokens streamtoken, username, apikey and filename with corresponding values from Plotly settings.
This application uses Plotly SDK form GitHub. I took the plotly_streaming_wifi source and ported to Spark Core. It is only a simple and straightforward port, only two modification done. 1. Copy the method dtostrf from this location and included in Plotly class and 2. commented the method void print_(const __FlashStringHelper*d) because this method was causing some compiler errors (I didn't dig deep into it, just commented the method).