MagicMirror and adruino over ethernet

[sdetweil]

@Kereknjek basically the arduino sends text strings with Serial.println(“[COMMAND:NAME:DATA]”)

To transmit a sensor data to the module: `[sensor:SENSOR_NAME:SENSOR_VALUE]**

Example:

Serial.println(“[sensor:MQ2:19]”);
Serial.println(“[sensor:LM35:11]”);
Serial.println(“[sensor:HCSR04:64]”);

but anyhow, lots of work in the arduino code to make this work

[Kereknjek]

@sdetweil
That part is perfectly clear.

Here is C/P of what I am using now:

      client.println("< !DOCTYPE HTML >");
      client.println("< html >");
      client.print("Napon panela: ");
      client.print(PanelU);
      client.println(" V < br/>");
      client.print("Struja panela: ");
      client.print(PanelI);
      client.println(" A < br/>");
      client.print("Napon baterije: ");
      client.print(BatU);
      client.println(" V < br/>");

.
.
.
client.println(“< / html >”);

That is slightly modified ethernet server sample program from ethernet library.

Edit: had to add spaces because html wasn’t showing.

[BD0G]

This may be a stupid question , but . Why not just use the MMM-iFrame Module since the information is already provided /served from a webserver within the Arduino? You can change the size of the iFrame that displays the Url so that it can be small and take up just a little of the magic mirror or large and fill the mirror. Since you will not be touching the screen to change or interact with the data.

[Kereknjek]

It’s not stupid question.

If arduino serves webpage, it should be served from sd card.
To use sd card, you have to use sd card library, make decisions wether client wants whole web page or just data packets…
All that takes a lot of memory and time to process. And arduino is slow and low on memory compared to RPi.
For arduino is much simpler to detect “give me data” and send sensor ID and value.

Plus, in my case, arduino mega has 16 amperemeters to read and 18 outputs to regulate.
I wouldn’t like it if it gets stuck in code while inverter is working at full capacity. It could become fire hazard.

[BD0G]

@Kereknjek So in a nutshell. Yes the Arduino can serve a whole webpage of data , but it will take a long time. If one just sends the data from the Arduino to the Raspberry Pi then the Raspberry Pi can display the webpage faster as its processor and potentially memory is faster.

[Kereknjek]

Yes. Plus, if I would want to make any modifications to webpage, first I would have to shutdown arduino and whole solar system, pull sd card out, modify page, plug sd card back in and restart sytem.

If sd card gets damaged in any way or get slow for some reason (had one like that on my 3D printer), whole system running on that arduino gets slow and unuseable.

[sdetweil]

@Kereknjek cool. You could make a little change and have it return just data.

If the path is sensor1, send just sensor1’s data. Etc.

Pretty easy, just a case stmt… you could make it json data pretty easy too…

The request could ask for a sensor or block of sensors, and send raw data.

[sdetweil]

On my Arduino measuring water flow and water volume. I did those in interrupt and timer routines. And sent data in the main path.

[BD0G]

@Kereknjek Sounds like you need to backup the entire SD Card of your Arduino and create an image for safe keeping. If you Download Win32 Disk Imager you can create an image of the entire SD card and write it to a hard drive. Then if catastrophe strikes simply remove the SD card and use Win 32 Disk Imager to write the working image back to the SD card.

It can be downloaded here Win32DiskImager

[sdetweil]

@BD0G my 8266 has onboard flash ram. No SD card required.