Step 1) Get thyself an account with Particle.io
Step 2) Setup your Boron, at https://setup.particle.io/.
Step 3) Check out your Particle Sandbox at: https://console.particle.io/events. The panels can be accessed via icons at the left.
Click on ‘Devices’ — you should see the device that you just set up listed.
Click on ‘Events’. If you unplug your Boron from USB, and plug it back in, you should see events logged in this panel. Note that events are only recorded when this panel is active at the time events are published from your Boron.
Step 4) Go the Web IDE, at https://build.particle.io/build/new.
Step 5) Click an example app 1, ‘Blink an LED’, and flash your device.
Step 6) Modify the code to change the flashing sequence, or something else about, and reflash.
Step 7) Wire up a sensor, find library for either Adafruit MPL3115A2, or Particle SI7021, as appropriate.
Learn about the publish() function at: https://docs.particle.io/reference/device-os/api/cloud-functions/particle-publish/. There are some easy to follow examples. Note – you should delay about 10 seconds or more between publishing events — otherwise the network will automatically throttle your device down.
Write code to read the sensor, format the value, and publish the result. Flash your code.
Step 8) Observe the result on the Particle Console Events panel. If your code does publish events, the values should appear.