digraph G {
    antenna [shape=ellipse];

    subgraph cluster0 {
        node [style=filled,color=white];
        color=blue;

        subgraph cluster6 {
            node [style=filled, shape=box, style=filled, color=lightgrey];
            LoRa [label = "RFM95 transceiver"];
            labeljust = l;
            color=lightgrey;
            label = "LoRa module";
        }

        antenna -> LoRa [dir=both]
        LoRa -> LoRaSR [dir=both,label = "SPI"];

        subgraph cluster2 {
            node [style=filled, shape=box, style=filled, color=lightgrey];
            SDfiles [label = "Static Web App\n\n Vector Map Tiles"];
            labeljust = l;
            color=lightgrey;
            label = "SD card file system";
        }

        subgraph cluster1 {
            node [style=filled,color=white];
            style=filled;
            color=lightgrey;
            subgraph cluster3 {
                node [style=filled,color=white];
                color=red;
                LoRaSR [label = "LoRa send/receive"];
                WebServer [label = "Web Server"];
                LoRaSR -> WebServer [dir=both];
                labeljust = l;
                label = "firmware";
            }
            FS -> WebServer;
            subgraph cluster4 {
                node [style=filled,color=white];
                color=green;
                FS [label = "Static Web App"];
                labeljust = l;
                label = "on-board file system"
            }
            WiFiAntenna [label="WiFi Antenna",shape=box,style=filled,color=blue];
            labeljust = l;
            label = "ESP8266";
        }
        SDfiles -> WebServer [dir=both,label = "SPI"]; 
        WebServer -> WiFiAntenna;
        label = "disaster.node1";
    }
    WiFiAntenna -> JS [dir=both, label="websocket connection"];
    subgraph cluster5 {
        node [style=filled,color=white];
        color=yellow;
        JS [shape=none,label = "Running Web App"]
        JS -> maps [dir=both];
        JS -> apps [dir=both];
        JS -> chat [dir=both];
        label = "client device"
    }

    disasternode2 [label = "disaster.node2", shape = "box", color = blue]

    antenna -> disasternode2 
    disasternode2 -> antenna [label = "900MHz RF"];

}