Payload Parsing and Saving

This scene can be subdivided in 3 steps:

• Step 1: Get the initial data Each scene for parsing the node payload always starts like this:

    Origin = resiot_startfrom() -- Variable that contains a string to understand from which origin the scene started
    if Origin == "Manual" then -- This scene was started manually by clicking the "play" button below this screen
        -- If the scene has been started manually then these test values are taken into account
        AppEUI = "0102030405060708"
        DevEUI = "0102030405060708"
        Port = "1"
        Payload = resiot_hexdecode("07FB04BA")
    else -- If the scene has not been started manually
        -- In this case, the function "resiot_comm_getparam" is used to obtain the data of the node that can be used later
        AppEUI = resiot_comm_getparam("appeui") -- To derive the value of the Application EUI you have to write "appeui" inside the function
        DevEUI = resiot_comm_getparam("deveui") -- To derive the value of the Device EUI you have to write "deveui" inside the function
        Port = resiot_comm_getparam("port") -- To know from which door the message has been sent, write "port"
        -- To get the payload just arrived write "payload" inside the function, however this returns the payload in string format, 
        -- so to get instead an array of Bytes we must add the function "resiot_hexdecode" as shown below
        Payload = resiot_hexdecode(resiot_comm_getparam("payload"))
    end

• Step 2: Get the data from the Payload The second step consists in obtaining the data that will then be processed to obtain the desired values.
  Here are some functions that are usually used:

    ---------------------------------------------------------------------
    ------ SINGLE BYTES CHECK -------------------------------------------
    ---------------------------------------------------------------------
    if Payload[1] == 0x2a then
        -- The first Byte is "2a"
    elseif Payload[1] == 0x2b then
        -- The first Byte is "2b"
    else
        -- The first Byte is neither "2a" or "2b"
    end
    ---------------------------------------------------------------------
    ------ BYTE ARRAY TO INT --------------------------------------------
    ---------------------------------------------------------------------
    ByteArray2 = {Payload[1],Payload[2]}                       -- Array of 2 Bytes
    ByteArray4 = {Payload[1],Payload[2],Payload[3],Payload[4]} -- Array of 4 Bytes

    ValueBE16 = resiot_ba2intBE16(ByteArray2) -- INT16 Big Endian
    resiot_debug(ValueBE16)

    ValueBE32 = resiot_ba2intBE32(ByteArray4) -- INT32 Big Endian
    resiot_debug(ValueBE32)

    ValueLE16 = resiot_ba2intLE16(ByteArray2) -- INT16 Little Endian
    resiot_debug(ValueBE16)

    ValueLE32 = resiot_ba2intLE32(ByteArray4) -- INT32 Little Endian
    resiot_debug(ValueBE32)
    ---------------------------------------------------------------------
    ------ BYTE ARRAY TO FLOAT ------------------------------------------
    ---------------------------------------------------------------------
    ByteArray4 = {Payload[1],Payload[2],Payload[3],Payload[4]} -- Array of 4 Bytes

    ValueF32BE = resiot_ba2float32BE(ByteArray4) -- FLOAT32 Big Endian
    resiot_debug(ByteArray4)

    ValueF32LE = resiot_ba2float32LE(ByteArray4) -- FLOAT32 Little Endian
    resiot_debug(ByteArray4)
    ---------------------------------------------------------------------
    ------ BIT READ -----------------------------------------------------
    ---------------------------------------------------------------------
    Byte = 0x33 -- BYTE
    Index = 2   -- Position of BIT
    BitValue = resiot_readbit(Byte, Index)
    -- 0x33 = 0 0 1 1 0 0 1 1 -- Example of Byte
    -- Index  0 1 2 3 4 5 6 7 -- Index value for bit position
    -- If bit is 1 then BitValue = true
    -- If bit is 0 then BitValue = false
    ---------------------------------------------------------------------
    ---------------------------------------------------------------------
    ---------------------------------------------------------------------

• Step 3: Save the values within the Node Fields Last step, the values obtained must be saved inside the node fields.
  The functions to perform this action are 2:

    AllWorked, Error = resiot_setnodevalue(AppEUI, DevEUI, FieldName, tostring(Value))

    -- AppEUI = AppEUI of the node you want to save the value into.
    -- DevEUI = DevEUI of the node you want to save the value into.
    -- FieldName = The name of the field of the node.
    -- Value = Numeric/String/Boolean value that need too be saved. 
    -- "tostring()" is needed to covert the value into a string
    -- The function return 2 values:
    --
    -- AllWorked = Boolean value that is true when everything went well
    -- Error = if AllWorked is false the error message is written here

    TimeNow = os.time()
    Date = TimeNow - 3600 -- One Hour ago
    AllWorked, Error = resiot_setnodevaluewithtime(AppEUI, DevEUI, Tag, tostring(Value), Date)

    -- AppEUI = AppEUI of the node you want to save the value into.
    -- DevEUI = DevEUI of the node you want to save the value into.
    -- FieldName = The name of the field of the node.
    -- Value = Numeric/String/Boolean value that need too be saved. 
    -- "tostring()" is needed to covert the value into a string
    -- Date = Time in seconds
    -- Example:
    --
    -- 1 Hour ago: Date = os.time() - 3600 -- 3600 is 1 Hour in seconds
    -- 2 Hours ago: Date = os.time() - 7200 -- 7200 is 2 Hours in seconds
    -- 12 Hours ago: Date = os.time() - 43200 -- 43200 is 12 Hours in seconds
    -- 1 Day ago: Date = os.time() - 86400 -- 86400 is 1 Day in seconds
    -- 1 Week ago: Date = os.time() - 604800 -- 604800 is 1 Week in seconds

Practical Examples

Model GlobalSat LT100 Parsing Scene Example

• Node Fields

• Parsing Scene

-- Step 1:
LDSourceOrigin = resiot_startfrom()

if LDSourceOrigin == "Manual" then 
    Payload = resiot_hexdecode("")
    Port = "99"
    DevEUI = ""
    AppEUI = ""
else
    Payload, err = resiot_hexdecode(resiot_comm_getparam("payload"))
    Port = resiot_comm_getparam("port")
    DevEUI = resiot_payload_getparam("deveui")
    AppEUI = resiot_payload_getparam("appeui")
end

-- Step 2:

GPSFixStatus1 = resiot_readbit(Payload[2], 0)
GPSFixStatus2 = resiot_readbit(Payload[2], 1)
GPSFixStatus = ""

ReportType1 = resiot_readbit(Payload[2], 2)
ReportType2 = resiot_readbit(Payload[2], 3)
ReportType3 = resiot_readbit(Payload[2], 4)
ReportType4 = resiot_readbit(Payload[2], 5)
ReportType5 = resiot_readbit(Payload[2], 6)
ReportType6 = resiot_readbit(Payload[2], 7)
ReportType = 0
ReportTypeStr = ""

Battery = Payload[3] -- MU: %

Latitude = resiot_ba2intBE32({Payload[4], Payload[5], Payload[6], Payload[7]}) * 0.000001 -- MU: degree (°)
Longitude = resiot_ba2intBE32({Payload[8], Payload[9], Payload[10], Payload[11]}) * 0.000001 -- MU: degree (°)

-- Step 3:

if GPSFixStatus1 == false and GPSFixStatus2 == false then
    GPSFixStatus = "Not Fix"
elseif GPSFixStatus1 and GPSFixStatus2 == false then
    GPSFixStatus = "3D"
elseif GPSFixStatus1 == false and GPSFixStatus2 then
    GPSFixStatus = "2D"
end

if ReportType6 then
    ReportType = ReportType + 1
end
if ReportType5 then
    ReportType = ReportType + 2
end
if ReportType4 then
    ReportType = ReportType + 4
end
if ReportType3 then
    ReportType = ReportType + 8
end
if ReportType2 then
    ReportType = ReportType + 16
end
if ReportType1 then
    ReportType = ReportType + 32
end

if ReportType == 2 then
    ReportTypeStr = "Periodic mode report"
elseif ReportType == 4 then
    ReportTypeStr = "Motion mode static report"
elseif ReportType == 5 then
    ReportTypeStr = "Motion mode moving report"
elseif ReportType == 6 then
    ReportTypeStr = "Motion mode static to motion report"
elseif ReportType == 7 then
    ReportTypeStr = "Motion mode moving to static report"
elseif ReportType == 14 then
    ReportTypeStr = "SOS alarm report"
    resiot_raiseevent(AppEUI, DevEUI, "SOS")
elseif ReportType == 15 then
    ReportTypeStr = "Low battery alarm report"
    resiot_raiseevent(AppEUI, DevEUI, "Low_Battery")
elseif ReportType == 17 then
    ReportTypeStr = "Power on(temperature)"
elseif ReportType == 19 then
    ReportTypeStr = "Power off(low battery)"
elseif ReportType == 20 then
    ReportTypeStr = "Power off(temperature)"
end

-- Step 4:

resiot_setnodevalue(AppEUI, DevEUI, "GPS_Fix_Status", GPSFixStatus)
resiot_setnodevalue(AppEUI, DevEUI, "Report_Type", tostring(ReportType))
resiot_setnodevalue(AppEUI, DevEUI, "Report_Type_Str", ReportTypeStr)
resiot_setnodevalue(AppEUI, DevEUI, "Battery", tostring(Battery))
resiot_setlatitudelongitude(AppEUI, DevEUI, Latitude, Longitude)