# How to make an IoT protocol (parsing, answering)?

**URL:** <https://discourse.nodered.org/t/how-to-make-an-iot-protocol-parsing-answering/7691>\
**Category:** General\
**Created:** [7 February 2019 07:41 UTC](https://discourse.nodered.org/t/how-to-make-an-iot-protocol-parsing-answering/7691 "2019-02-07T07:41:14Z")\
**Posts on this page:** 20\
**Page:** 4

<div class="post-metadata">

**Author:** ![jycemea](https://avatars.discourse-cdn.com/v4/letter/j/f475e1/32.png) [@jycemea](https://discourse.nodered.org/u/jycemea)\
**Post date:** [13 February 2019 14:42 UTC](https://discourse.nodered.org/t/how-to-make-an-iot-protocol-parsing-answering/7691/61 "2019-02-13T14:42:21Z")

</div>

Hi Colin, thanks for this... I already identified the problem between , and ; ... but even with that mistake corrected, as there is also space between symbols on [https://www.w3schools.com/js/js\_loop\_for.asp](https://www.w3schools.com/js/js_loop_for.asp), it is impossible to understand from what exactly is coming the real problem.. as there is no debug messages anymore in my nodered  
Yesterday, I'be been able to get the splited messages I sent you when I excluded your :

**let i;**  
**...**  
**}**

I can look forward now

---

<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [13 February 2019 14:44 UTC](https://discourse.nodered.org/t/how-to-make-an-iot-protocol-parsing-answering/7691/62 "2019-02-13T14:44:44Z")

</div>

The space after the `;` is not important, if that is what you mean, nor is it important round operators such as `=` or `+`

---

<div class="post-metadata">

**Author:** ![jycemea](https://avatars.discourse-cdn.com/v4/letter/j/f475e1/32.png) [@jycemea](https://discourse.nodered.org/u/jycemea)\
**Post date:** [13 February 2019 16:06 UTC](https://discourse.nodered.org/t/how-to-make-an-iot-protocol-parsing-answering/7691/63 "2019-02-13T16:06:28Z")

</div>

Unfortunatly, the result is not ok as for :

```auto
[{"id":"38fd6d46.07d862","type":"tab","label":"IWAP02","disabled":false,"info":""},{"id":"4a330da4.5ac7b4","type":"inject","z":"38fd6d46.07d862","name":"TEST IWAP02#","topic":"","payload":"IWAP02,zh_cn,0,7,460,0,9520|3671|13,9520|3672|12,9520|3673|11,9520|3674|10,9520|367 5|9,9520|3676|8,9520|3677|7#","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":114,"y":132.7999906539917,"wires":[["b13eed31.409e9"]]},{"id":"b13eed31.409e9","type":"switch","z":"38fd6d46.07d862","name":"SORT INCOMING","property":"payload","propertyType":"msg","rules":[{"t":"regex","v":"^IWAP02","vt":"str","case":false}],"checkall":"true","repair":false,"outputs":1,"x":381.00000381469727,"y":143.8000030517578,"wires":[["97b7209d.3d45"]]},{"id":"168c17f3.e614a8","type":"comment","z":"38fd6d46.07d862","name":"INCOMING MESSAGES FROM THE WATCH","info":"","x":177.3000030517578,"y":22,"wires":[]},{"id":"e6d39b5d.4017e8","type":"comment","z":"38fd6d46.07d862","name":"OUTGOING MESSAGES TO THE WATCH","info":"","x":184.00000762939453,"y":355.8000297546387,"wires":[]},{"id":"f8900c11.a7614","type":"change","z":"38fd6d46.07d862","name":"IWBP02# ","rules":[{"t":"set","p":"payload","pt":"msg","to":"IWBP02# ","tot":"str"}],"action":"","property":"","from":"","to":"","reg":false,"x":97.00000762939453,"y":428.80000591278076,"wires":[["2817006d.81197"]]},{"id":"2817006d.81197","type":"debug","z":"38fd6d46.07d862","name":"outgoing debug","active":false,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","x":864.3000106811523,"y":354.2000045776367,"wires":[]},{"id":"21466e3.35e1792","type":"change","z":"38fd6d46.07d862","name":"IWBP02 LBS ADDRESS","rules":[{"t":"set","p":"payload","pt":"msg","to":"ADDRESS NEEDED","tot":"str"}],"action":"","property":"","from":"","to":"","reg":false,"x":152.00000762939453,"y":492.0000057220459,"wires":[["2817006d.81197"]]},{"id":"9cd8efdf.edd82","type":"inject","z":"38fd6d46.07d862","name":"TEST IWAP02_ADDRESS","topic":"","payload":"IWAP02,zh_cn,1,7,460,0,9520|3671|13,9520|3672|12,9520|3673|11,9520|3674|10,9520|367 5|9,9520|3676|8,9520|3677|7,4,1|D8-24-BD-79-FA-1F|59&2|3C-46-D8-6D-CE-01|81&3|0C-4C-39-1A-7C-65|69&4|70-A8-E3-5D-D7-C0|65#","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":143,"y":211.00000381469727,"wires":[["b13eed31.409e9"]]},{"id":"97b7209d.3d45","type":"function","z":"38fd6d46.07d862","name":"split flag 0/1","func":"// flag 0 to split\n//IWAP02,zh_cn,0,7,460,0,9520|3671|13,9520|3672|12,9520|3673|11,9520|3674|10,9520|3675|9,9520|3676|8,9520|3677|7#\nlet answer = {} \nlet elements = msg.payload.split(\",\") // this gives an array containing the bits\nanswer.command = elements[0] // IWAP02\nanswer.languageNotice = elements[1] // zh_cn\nanswer.flag = elements[2] // 0\nnode.warn(`flag is: ${answer.flag}`) // warning flag\nanswer.baseCount = elements[3] // 7\n// you can work out how to put the node.warn statements in yourself\nanswer.mcc = elements[4] // 460\nanswer.mnc = elements[5] // 7\n// now need to get the bases\nlet i;\nanswer.bases = []\nfor (i=6; i<6+answer.baseCount; i++) {\n let baseElements = elements[i].split(\"|\")\n answer.push({lac: baseElements[0], cid: baseElements[1], dbm: baseElements[2]})\n}\n// the rest needs to go in here\nmsg.payload = answer\nreturn msg","outputs":2,"noerr":0,"x":713.3000068664551,"y":144.20001411437988,"wires":[["343e90e6.de5b1"],[]],"outputLabels":[" 0","1"]},{"id":"343e90e6.de5b1","type":"debug","z":"38fd6d46.07d862","name":"incoming debug","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"payload","x":723.0000114440918,"y":209.00000286102295,"wires":[]}]

```

The error :

**13/02/2019 à 17:10:100:**  
\*\* [node: split flag 0/1]function : (error)\*\*  
**"TypeError: answer.push is not a function"**

I've also lost all the others infos ( command / languageNotice, mcc, mnc, ...) if I'm using :  
**let i;**  
**answer.bases = []**  
**for (i=6; i\<6+answer.baseCount; i++) {**  
\*\* let baseElements = elements[i].split("|")\*\*  
\*\* answer.push({lac: baseElements[0], cid: baseElements[1], dbm: baseElements[2]})\*\*  
**}**

In the code you gave me you also wrote :  
**// the rest needs to go in here**... What dou you mean Colin?

Thanks...

---

<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [13 February 2019 16:13 UTC](https://discourse.nodered.org/t/how-to-make-an-iot-protocol-parsing-answering/7691/64 "2019-02-13T16:13:18Z")

</div>

> [@jycemea](#):
>
> answer.push(

Sorry, that should be `answer.bases.push(` It pushes the new base onto the end of the array `answer.bases`  
The others won't appear because it failed before it got as far as sending the answer.  
When I said the rest goes here I meant you can work out the rest of the elements of that message yourself, now that you have learnt a bit of javascript. It is just more of what has gone before at the start of the function.

---

<div class="post-metadata">

**Author:** ![jycemea](https://avatars.discourse-cdn.com/v4/letter/j/f475e1/32.png) [@jycemea](https://discourse.nodered.org/u/jycemea)\
**Post date:** [13 February 2019 16:19 UTC](https://discourse.nodered.org/t/how-to-make-an-iot-protocol-parsing-answering/7691/65 "2019-02-13T16:19:03Z")

</div>

Let's try Colin but still errors :

function : (error)

"TypeError: Cannot read property 'split' of undefined"

I forgot to ask :  
1/ you splited with **,**  
2/ you are doing a loop to split with **|**

Is there still something to repeat as there still **,** after **|** in the code ?

---

<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [13 February 2019 16:43 UTC](https://discourse.nodered.org/t/how-to-make-an-iot-protocol-parsing-answering/7691/66 "2019-02-13T16:43:54Z")

</div>

The error is because for getting the base count I put  
`answer.baseCount = elements[3]`  
but it should be  
`answer.baseCount = Number(elements[3])`  
That is because we need the count as a number 7 not the letter 7 so we can add 6 to it to do the test.  
While looking at that I see that I think you have an error in your inject strings, you have a space in the middle that should be a comma.

The initial split is on comma because comma splits it into  
IWAP02  
zh\_cn  
0  
7  
460  
0  
9520|3671|13  
9520|3672|12  
and so on.  
Then the split using | splits 9520|3671|13 into the three separate parts.

---

<div class="post-metadata">

**Author:** ![jycemea](https://avatars.discourse-cdn.com/v4/letter/j/f475e1/32.png) [@jycemea](https://discourse.nodered.org/u/jycemea)\
**Post date:** [13 February 2019 16:53 UTC](https://discourse.nodered.org/t/how-to-make-an-iot-protocol-parsing-answering/7691/67 "2019-02-13T16:53:53Z")

</div>

Thanks!!! You are a genius!

---

<div class="post-metadata">

**Author:** ![jycemea](https://avatars.discourse-cdn.com/v4/letter/j/f475e1/32.png) [@jycemea](https://discourse.nodered.org/u/jycemea)\
**Post date:** [14 February 2019 15:49 UTC](https://discourse.nodered.org/t/how-to-make-an-iot-protocol-parsing-answering/7691/68 "2019-02-14T15:49:51Z")

</div>

Hi Colin, coming back to Node-Red, for split command

You wrote previously... " **then I suggest doing it _after_ the function node. You can use `msg.payload.flag` to switch on**". As usually, I understand what is the process (if flag = 0 then =\> output 1, if flag = 1 then =\> output 2)  
But do you mean this command needs to be included in the present function node or have I to use in another node...?

// flag 0 to split  
//IWAP02,zh\_cn,0,7,460,0,9520|3671|13,9520|3672|12,9520|3673|11,9520|3674|10,9520|3675|9,9520|3676|8,9520|3677|7#  
let answer = {}  
let elements = msg.payload.split(",") // this gives an array containing the bits  
answer.command = elements[0] // IWAP02  
answer.languageNotice = elements[1] // zh\_cn  
**answer.flag = elements[2]** // 0  
**node.warn(`flag is: ${answer.flag}`)**  
// warning flag  
answer.baseCount = Number(elements[3]) // 7  
// you can work out how to put the node.warn statements in yourself  
answer.mcc = elements[4] // 460  
answer.mnc = elements[5] // 7  
// now need to get the bases  
let i;  
answer.bases = []  
for (i=6; i\<6+answer.baseCount; i++) {  
let baseElements = elements[i].split("|")  
answer.bases.push({lac: baseElements[0], cid: baseElements[1], dbm: baseElements[2]})  
}  
// the rest needs to go in here  
msg.payload = answer  
return msg

---

<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [14 February 2019 16:17 UTC](https://discourse.nodered.org/t/how-to-make-an-iot-protocol-parsing-answering/7691/69 "2019-02-14T16:17:22Z")

</div>

Add a Switch node after the function node. The switch node has the flad in msg.payload.flag, so you can switch if msg.payload.flag = 0 then o/p 1, if msg.payload.flag = 1 then o/p 2

---

<div class="post-metadata">

**Author:** ![jycemea](https://avatars.discourse-cdn.com/v4/letter/j/f475e1/32.png) [@jycemea](https://discourse.nodered.org/u/jycemea)\
**Post date:** [14 February 2019 16:18 UTC](https://discourse.nodered.org/t/how-to-make-an-iot-protocol-parsing-answering/7691/70 "2019-02-14T16:18:23Z")

</div>

Thks Colin!

---

<div class="post-metadata">

**Author:** ![jycemea](https://avatars.discourse-cdn.com/v4/letter/j/f475e1/32.png) [@jycemea](https://discourse.nodered.org/u/jycemea)\
**Post date:** [14 February 2019 17:27 UTC](https://discourse.nodered.org/t/how-to-make-an-iot-protocol-parsing-answering/7691/71 "2019-02-14T17:27:41Z")

</div>

There is still an important job on IWAP02 if the answer "flag = 1". But I need more infos about it.

So ... let's go for **IWAP01**!!! 🙂 Here, it is the same same idea as **IWAP02**... but no need to setup the watch with the answer...

// flag A (valid)  
//IWAP01080524 **A** 2232.9806N11404.9355E000.1061830323.8706000908000102,460,0,9520,3671#

where : **IWAP01** = Command ; **080524** = 24th May 2008  
“ **A** ”shows valid data,” **V** ”shows invalid data and will call additional LBS data (same idea as in IWAP02 with flag = 0 / flag = 1) ; **2232.9806N11404.9355E** = 22 degrees north latitude 32.9806 point ，114 degrees east longitude 04.9355 points ; 000.1 = moving speed ; **061830** = GMT 06:18:30 ; **323.87** = direction angle as 323.87° ; **060** = GSM signal ; **009** = number of satellites ; **080** = battery level ; **0** = remaining space , **01** = fortification state ; **02** = working mode ; **460** =mcc ; **0** =mnc ; **9520** = lac ; **3671** = cid

If state in GPS package is V (for invalid datas) or latitude and longitude are 0000.0000N00000.0000E, it will call additional LBS data (same idea as IWAP02)

// flag V (invalid)  
//IWAP01080524 **V** 0000.0000N00000.0000E000.1061830323.8706000908000102,460,0,9520,3671, **Home|74-DE-2B-44-88-8C|97&Home1|74-DE-2B-44-88-8C|97&Home2|74-DE-2B-44-88-8C|97&Home3|74-DE-2B-44-88-8C|97** #

where : **Home** = SSID ; **74-DE-2B-44-88-8C** = MAC address ; **97** = signal strength. Variables are separated by“ **|** ”, wifi information can be multiple sets and are separated by “ **&** ”.

I think I can use a part of your code for IWAP02 but I really don't know for the first splits...

---

<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [14 February 2019 17:35 UTC](https://discourse.nodered.org/t/how-to-make-an-iot-protocol-parsing-answering/7691/72 "2019-02-14T17:35:00Z")

</div>

That message is much more difficult to split up. Whoever designed that  
Are all the numbers up to the first comma always the same number of digits? If so we can do it by extracting the right number of digits.

What do you mean by  
"but no need to setup the watch with the answer..."

---

<div class="post-metadata">

**Author:** ![jycemea](https://avatars.discourse-cdn.com/v4/letter/j/f475e1/32.png) [@jycemea](https://discourse.nodered.org/u/jycemea)\
**Post date:** [14 February 2019 17:43 UTC](https://discourse.nodered.org/t/how-to-make-an-iot-protocol-parsing-answering/7691/73 "2019-02-14T17:43:35Z")

</div>

Of course, it will be always the same number of digits. The problem is just to convert **2232.9806N11404.9355E** in decimal... but i found a code for this and I don't know how to integrate inside :

```auto
[{"id":"9f3e71b9.bc689","type":"tab","label":"GPS_TextTODecimal","disabled":true,"info":""},{"id":"3de636fc.7cbd1a","type":"debug","z":"9f3e71b9.bc689","name":"","active":true,"console":"false","complete":"false","x":830.0000114440918,"y":192.00000190734863,"wires":[]},{"id":"5dd83314.546c0c","type":"function","z":"9f3e71b9.bc689","name":"Convert NMEA to decimal","func":"//Example of data received:\n//GPRMC,123519,A,4807.038,N,01131.000,E,022.4,084.4,230394,003.1,\n\nmessage0 = {};\nmessage1 = {};\nmessage2 = {};\nmessage3 = {};\nmessage4 = {};\nmessage5 = {};\nmessage6 = {};\nmessage7 = {};\nmessage8 = {};\nmessage9 = {};\nmessage10 = {};\nmessage11 = {};\nvar symblat = \"\";\nvar symblong = \"\";\n\n\nmsg.string = msg.payload.split(\",\");\n\n//Find if latitude is south and add minus\nif (msg.string[4] == \"S\") {\nsymblat = \"-\";\n} else {\n\n}\n\n//Find if longitude is west and add minus\nif (msg.string[6] == \"W\") {\nsymblong = \"-\";\n} else {\n\n}\n\nvar nvals = msg.payload.match(/,(\\d+)(\\d\\d\\.\\d+),(N|S)/);\nvar evals = msg.payload.match(/,(\\d+)(\\d\\d\\.\\d+),(E|W)/);\nmsg.payload = {\n name:\"Position test\",\n lat: symblat + (+nvals[1] + nvals[2]/60).toFixed(4),\n lon: symblong + (+evals[1] + evals[2]/60).toFixed(4)\n}\n\nreturn [msg];","outputs":"1","noerr":0,"x":532,"y":191.00000190734863,"wires":[["3de636fc.7cbd1a"]]},{"id":"6bba3817.9c61a8","type":"inject","z":"9f3e71b9.bc689","name":"31.426391,S,64.191494,W","topic":"","payload":"GPRMC,161935.00,A,3125.58347,S,06411.48964,W,0.030,,221217,,,A*66","payloadType":"str","repeat":"","crontab":"","once":false,"x":181,"y":111.00000190734863,"wires":[["5dd83314.546c0c"]]},{"id":"a303b32b.20425","type":"inject","z":"9f3e71b9.bc689","name":"46.671974°N 71.734865°W","topic":"","payload":"$GPRMC,161935.00,A,4640.31845,N,07144.09187,W,0.030,,221217,,,A*66","payloadType":"str","repeat":"","crontab":"","once":false,"x":195,"y":201.00000190734863,"wires":[["5dd83314.546c0c"]]},{"id":"1810a5a2.3a852a","type":"comment","z":"9f3e71b9.bc689","name":"Córdoba, Argentine","info":"","x":160,"y":69.00000190734863,"wires":[]},{"id":"1389f752.21eea9","type":"comment","z":"9f3e71b9.bc689","name":"Donnacona, Canada","info":"","x":160,"y":157.00000190734863,"wires":[]},{"id":"b9895164.66836","type":"comment","z":"9f3e71b9.bc689","name":"Tokyo, Japon","info":"","x":141,"y":250.00000190734863,"wires":[]},{"id":"5495a5fd.d6181c","type":"inject","z":"9f3e71b9.bc689","name":"46.671974°N 71.734865°W","topic":"","payload":"$GPRMC,161935.00,A,3541.22155,N,13941.30142,E,0.030,,221217,,,A*66","payloadType":"str","repeat":"","crontab":"","once":false,"x":196,"y":295.00000190734863,"wires":[["5dd83314.546c0c"]]},{"id":"a335669c.b093c8","type":"comment","z":"9f3e71b9.bc689","name":"Sydney, Australie","info":"","x":147,"y":337.00000190734863,"wires":[]},{"id":"d3930048.93dea","type":"inject","z":"9f3e71b9.bc689","name":"33.879585°S 151.205577°E","topic":"","payload":"$GPRMC,161935.00,A,3352.7751,S,15112.33463,E,0.030,,221217,,,A*66","payloadType":"str","repeat":"","crontab":"","once":false,"x":196,"y":376.00000190734863,"wires":[["5dd83314.546c0c"]]}]

```

**"What do you mean by**  
**"but no need to setup the watch with the answer...""**  
= just told there is no particular answer including datas to produce here...

---

<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [14 February 2019 17:54 UTC](https://discourse.nodered.org/t/how-to-make-an-iot-protocol-parsing-answering/7691/74 "2019-02-14T17:54:36Z")

</div>

> [@jycemea](#):
>
> just told there is no particular answer including datas to produce here.

Sorry, still don't understand

---

<div class="post-metadata">

**Author:** ![jycemea](https://avatars.discourse-cdn.com/v4/letter/j/f475e1/32.png) [@jycemea](https://discourse.nodered.org/u/jycemea)\
**Post date:** [14 February 2019 18:03 UTC](https://discourse.nodered.org/t/how-to-make-an-iot-protocol-parsing-answering/7691/75 "2019-02-14T18:03:18Z")

</div>

Sorry, it is not important for the actual node... I just said that the answer for **IWAP01** is the same whatever **flag = A** or **flag = V** It will be always **IWBP01#**

in contrary of the answer to write for **IWAP02** / when **flag = 1**... Because, in this case, the answer is the biggest problem to solve compared to the others ...

---

<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [14 February 2019 20:36 UTC](https://discourse.nodered.org/t/how-to-make-an-iot-protocol-parsing-answering/7691/76 "2019-02-14T20:36:28Z")

</div>

Ok, understood. I haven't got any more time this evening, will try to have a look at decoding the lat/lon tomorrow.  
If you wanted to make a start you could split it on commas initially, then in elements[0] will be the long string at the begining. This needs to be split using the substring function. That needs to be called multiple times to fetch each of the sections one at a time.

---

<div class="post-metadata">

**Author:** ![dceejay](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/dceejay/32/38_2.png) [@dceejay](https://discourse.nodered.org/u/dceejay)\
**Post date:** [14 February 2019 22:02 UTC](https://discourse.nodered.org/t/how-to-make-an-iot-protocol-parsing-answering/7691/77 "2019-02-14T22:02:31Z")

</div>

That initial part looks similar to NMEA (but isn't) so the flow you pointed at won't work as is...

```
2232.9806N11404.9355E

```

is 22 degress 32.9806 minutes North 114 degrees 04.9355 minutes East  
so to get decimal degress you need

```
latitude = 22 + (32.9806/60) and longitude = 114 + (04.9355/60) 

```

and make them negative if S (if not N) and W (if not E)

---

<div class="post-metadata">

**Author:** ![jycemea](https://avatars.discourse-cdn.com/v4/letter/j/f475e1/32.png) [@jycemea](https://discourse.nodered.org/u/jycemea)\
**Post date:** [15 February 2019 04:12 UTC](https://discourse.nodered.org/t/how-to-make-an-iot-protocol-parsing-answering/7691/78 "2019-02-15T04:12:03Z")

</div>

Thanks **dceejay**...

---

<div class="post-metadata">

**Author:** ![jycemea](https://avatars.discourse-cdn.com/v4/letter/j/f475e1/32.png) [@jycemea](https://discourse.nodered.org/u/jycemea)\
**Post date:** [15 February 2019 09:41 UTC](https://discourse.nodered.org/t/how-to-make-an-iot-protocol-parsing-answering/7691/79 "2019-02-15T09:41:48Z")

</div>

So, the story starts like this ... but does not work correctly, because I suppose the substring have to be included somewhere... 🙂

// flag A  
[//IWAP01080524A2232.9806N11404.9355E000.1061830323.8706000908000102](https://IWAP01080524A2232.9806N11404.9355E000.1061830323.8706000908000102),460,0,9520,3671#  
// flag V  
[//IWAP01080524V0000.0000N00000.0000E000.1061830323.8706000908000102](https://IWAP01080524V0000.0000N00000.0000E000.1061830323.8706000908000102),460,0,9520,3671,Home|74-DE-2B-44-88-8C|97&Home1|74-DE-2B-44-88-8C|97&Home2|74-DE-2B-44-88-8C|97&Home3|74-DE-2B-44-88-8C|97#

let answer = {}  
let elements = msg.payload.split(",")  
answer.part1 = elements[0] // IWAP01080524A2232.9806N11404.9355E000.1061830323.8706000908000102  
answer.mcc = elements[1] // 460  
answer.mnc = elements[2] // 0  
answer.lac = elements[3] // 9520  
answer.cid = elements[4] // 3671

[//answer.flag](https://answer.flag) = elements[2]  
[//node.warn](https://node.warn)(`flag is: ${answer.flag}`)  
// warning flag  
let i;  
answer.bases = []  
for (i=1; i\<1+answer.cid; i++) {  
let baseElements = elements[i].split("|")  
answer.bases.push({lac: baseElements[0], cid: baseElements[1], dbm: baseElements[2]})  
}  
return msg

---

<div class="post-metadata">

**Author:** ![Colin](https://sea2.discourse-cdn.com/flex026/user_avatar/discourse.nodered.org/colin/32/17040_2.png) [@Colin](https://discourse.nodered.org/u/Colin)\
**Post date:** [15 February 2019 10:16 UTC](https://discourse.nodered.org/t/how-to-make-an-iot-protocol-parsing-answering/7691/80 "2019-02-15T10:16:29Z")

</div>

Well I have made a start on decoding the first section

```auto
[{"id":"cf907e47.07511","type":"inject","z":"bae6d5e2.bea09","name":"Invalid IWAP01","topic":"","payload":"IWAP01190215V0000.0000N00000.0000E000.1061830323.8706000908000102,460,0,9520,3671,Home|74-DE-2B-44-88-8C|97&Home1|74-DE-2B-44-88-8C|97&Home2|74-DE-2B-44-88-8C|97&Home3|74-DE-2B-44-88-8C|97#","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":124.5,"y":221,"wires":[["4ecc3207.8feb4c"]]},{"id":"4ecc3207.8feb4c","type":"function","z":"bae6d5e2.bea09","name":"Split IWAP01","func":"let answer = {}\nlet elements = msg.payload.split(\",\") // this gives an array containing the bits\n// elements[0] is the long string starting IWAP01\nlet dateStr = elements[0].substr(6,6) // eg \"190215\" 15th Feb 2019\nanswer.date = new Date(Number(dateStr.substr(0,2))+2000, Number(dateStr.substr(2,2))-1, dateStr.substr(4,2))\nanswer.valid = (elements[0].substr(12,1) === \"A\") // true or false\nif (answer.valid) {\n let degreesN = Number(elements[0].substr(13,2))\n let minutesN = Number(elements[0].substr(15,7))\n let ns = elements[0].substr(22,1) // N or S\n let degreesE = Number(elements[0].substr(23,3))\n let minutesE = Number(elements[0].substr(26,7))\n let ew = elements[0].substr(33,1) // E or W\n node.warn(`${degreesN} ${minutesN} ${ns} ${degreesE} ${minutesE} ${ew}`)\n answer.latitude = degreesN + minutesN/60\n if (ns === \"S\") answer.latitude = -answer.latitude\n answer.longitude = degreesE + minutesE/60\n if (ew === \"W\") answer.longitude = -answer.longitude\n} else {\n answer.latitude = 0\n answer.longitude = 0\n}\n\nmsg.payload = answer\nreturn msg","outputs":1,"noerr":0,"x":310.5,"y":162,"wires":[["c5195512.cf66e"]]},{"id":"c5195512.cf66e","type":"debug","z":"bae6d5e2.bea09","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","x":489.5,"y":161,"wires":[]},{"id":"9d29ac9c.9ba0f","type":"inject","z":"bae6d5e2.bea09","name":"Valid IWAP01","topic":"","payload":"IWAP01190215A2232.9806N11404.9355E000.1061830323.8706000908000102,460,0,9520,3671#","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":0.1,"x":116,"y":124,"wires":[["4ecc3207.8feb4c"]]}]

```

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