logger.nut

local units = ["", "Wh", "kWh", "MWh", "GWh", "j", "kj", "Mj",
    "Gj", "Cal", "kCal", "Mcal", "Gcal", "varh",
	"kvarh", "Mvarh", "Gvarh", "VAh", "kVAh",
	"MVAh", "GVAh", "kW", "kW", "MW", "GW",
	"kvar", "kvar", "Mvar", "Gvar", "VA", "kVA",
	"MVA", "GVA", "V", "A", "kV", "kA", "C",
	"K", "l", "m3", "l/h", "m3/h", "m3xC",
	"ton", "ton/h", "h", "hh:mm:ss", "yy:mm:dd",
	"yyyy:mm:dd", "mm:dd", "", "bar", "RTC",
	"ASCII", "m3 x 10", "ton x 10", "GJ x 10",
	"minutes", "Bitfield", "s", "ms", "days",
	"RTC-Q", "Datetime"
]

local thingsToReceive = [
    {
        var = 0x000d,
        name = "Energy in hi-res"
    },
    {
        var = 0x041e,
        name = "Voltage p1"
    },
    {
        var = 0x041f,
        name = "Voltage p2"
    },
    {
        var = 0x0434,
        name = "Current p1"
    },
    {
        var = 0x0435,
        name = "Current p2"
    },
    {
        var = 0x0438,
        name = "Power p1"
    },
    {
        var = 0x0439,
        name = "Power p2"
    }
];

function isEscape(x) {
    if(x == 0x06) {
        return true;
    }
    if(x == 0x0d) {
        return true;
    }
    if(x == 0x1b) {
        return true;
    }
    if(x == 0x40) {
        return true;
    }
    if(x == 0x80) {
        return true;
    }
    return false;
}

function crc_1021(message) {
    local poly = 0x1021;
    local reg = 0x0000;
    
    foreach(byte in message) {
        local mask = 0x80;
        while(mask > 0) {
            //server.log(format("mask: %d",mask));
            reg = reg << 1;
            if(byte & mask) {
                reg = reg | 1;
            }
            mask = mask >> 1
            if(reg & 0x10000) {
                reg = reg & 0xffff;
                reg = reg ^ poly;
            }
        }
    }
    return reg;
}
        
function sendToKamstrup(pfx, msg) {
	local b = msg;

	b.append(0)
	b.append(0)
	local c = crc_1021(b)
    b[b.len()-2] = c >> 8;
    b[b.len()-1] = c & 0xff;

    c = [];
	c.append(pfx)
	foreach(i in b) {
		if(isEscape(i)) {
			c.append(0x1b)
			c.append(i ^ 0xff)
		} else {
			c.append(i);
		}
	}
    
	c.append(0x0d);
    foreach(send in c) {
        hardware.uart57.write(send);    
        //server.log(send);
    }
	
}
function recvKam() {
    hardware.uart57.flush();
	local b = [];
    local readErrors = 0;
	while(true) {
		local d = hardware.uart57.read();
        
		if(d == -1) {
    	    readErrors++;
            if(readErrors > 10) {
                return null;
            }
            imp.sleep(0.02);
            continue;
		}
		if(d == 0x40) {
			b = [];
		}
        //server.log(format("in: %d", d));
		b.append(d);
        
		if(d == 0x0d) {
    	    break;    
		}
	}
	local c = [];
	local i = 1;
	while(i < b.len() - 1) {
		if(b[i] == 0x1b) {
     		local v = b[i + 1] ^ 0xff;
			if(!isEscape(v)) {
    		    server.log(format("Missing Escape %02x" % v));    
			}
			c.append(v);
			i += 2;	    
		} else {
			c.append(b[i]);
			i += 1;
		}
	}
	if(crc_1021(c)) {
        server.log("CRC error");
	}
	
	return c;
}
function readvar(var) {
    
    
    sendToKamstrup(0x80,[0x3f, 0x10, 0x01, (var >> 8), (var & 0xff)]);
    local b = recvKam();
    if(b == null) {
		return {value = "TO", unit = "NA"};  
    }
	if(b[0] != 0x3f || b[1] != 0x10) {
        return {value = "NA", unit = "NA"};     
	}
	
	if(b[2] != (var >> 8) || b[3] != (var & 0xff)) {
        return {value = "NA", unit = "NA"};   
	}
    local u = "None";
	if(units[b[4]]) {
       u = units[b[4]] 
	}

	//Decode the mantissa
	local x = 0
    for (local i = 0; i < b[5]; i++) {
        x = x << 8;
        x = x | b[i + 7];
    }
    
	// Decode the exponent
	local i = b[6] & 0x3f;
	if(b[6] & 0x40) {
        i = -i;    
	}
	
    i = math.pow(10,i);
	
    if(b[6] & 0x80) {
        i = -i    
	}
	x *= i
    //return format("%g %s", x, u);
    return {value = format("%g", x), unit = u};
    
}

function readEverything() {
    nv.data = nv.data + format("%d,", time());
    foreach(x in thingsToReceive) {
        local response = readvar(x.var);
        nv.data = nv.data + format("%s,", response.value);    
        imp.sleep(0.1) //give kamstrup time to recover.. 
    }
    nv.data = nv.data + "\n";
    
}
// configure a pin pair for UART TX/RX
hardware.uart57.configure(9600, 8, PARITY_NONE, 1, NO_CTSRTS);
 

t <- time();
 
function hourly() {
    if(nv.data != "") {
        local output = OutputPort("data", "string");
        imp.configure("Kamstrup", [], [output]);
        server.log("Sending data...");
        local responseCode = output.set(nv.data);

        if(responseCode != 0) {
            if(responseCode == SEND_ERROR_NOT_CONNECTED) {
                server.log("Send error not connected");
            }
            if(responseCode == SEND_ERROR_TIMEOUT) {
                server.log("Send error timeout");
            }
            if(responseCode == SEND_ERROR_DISCONNECTED) {
                server.log("The connection was disconnected before all data was sent to the server.");
            }
        }
        server.log("Data sent... ");
        if(server.flush(20)) {
            server.log("Flush timed out");
        }
    } else {
        server.log("Nothing to send, first boot?");
    }

    nv.data = "";
    server.expectonlinein(3600);
    //server.expectonlinein(120);

}
 
function log() {
    if (!("nv" in getroottable())) {
        nv <- { data = "" };
        hourly();
    }
  local min = (t/60) % 60;
  readEverything();
  if (min == 59) {
      hourly();
  }
  imp.onidle(function() { imp.deepsleepfor(60 - (time() % 60)); });
  

}
 
log();


/*local dog = 0;
function watchdog() {
    server.show("Watchdog: " + dog.tostring());
    dog++;
    imp.wakeup(20, watchdog);
}
watchdog();*/