Advice on using Ethernet Lan on RPi to communicate with Particle Cloud


#1

Is there anything special required to use a wired LAN internet connection to talk to the Particle Cloud instead of WiFi - or is this just plug and go?


#2

Nothing special is required. Just plug in the Ethernet cable. If you can access the internet from your Pi, the Particle Cloud will be able to connect too.


#3

@jvanier Thanks for confirmation, another question. Are you aware of any out of the box solution to connect a Raspberry Pi GPIO port to photon headers. I am basically trying to make a photon with an ethernet connection instead of wifi that can be plugged into the headers on a PCB designed for the photon. Can I assume that just removing the calls WiFi functions will be all that is required to port photon sketches to the Pi?


#4

Hum, I think you’ll need to make a custom cable between the PCB and Pi. For my personal projects, I use these pre-crimped wires and these terminals.


#5

Last question, could you recommend a way to output to the RPi monitor/screen from the sketch - a graphics library similar Adafruit_ILI9341, etc. Or is this best done by serving HTML to a local IP and using a browser?


#6

A good example of this is the Particle Maker Faire 2017 Great Ball Machine. We built this big contraption last year and used a Raspberry Pi for the display. The UI was in a browser that talked to the firmware through HTTP.


#7

@jvanier Thanks, lots to try out here.


#8

@jvanier, having looked at the firmware and website javascript could I test how this appears to me to work?

The firmware (hero.ino) is reading data (inputs) from a CANBus with names/labels the same as the objects in the javascript DOM. These have either integer or float type values. Every 100 mS you open and write to a file /home/pi/can_signals.json with JSON [is this valid JSON? I guess it doesn’t matter] with each pair of data values {"#name":value, …}.

The webserver setup (root directory) and javascript (factory.js) is the bit I am really not so clear on. In the javascript I was expecting to see either JSON.parse() or AJAX/JQuery and $.getJSON()?

How does the website/server update when a new set of data if written in to the can_signals.json file?

I have tried a similar process - currently with a static file using both JSON.parse() and $.getJSON() and neither is working.