Created by gh-md-toc
Here is solution for the Gambit test task. It's original text is located below.
This project runs on laravel 5.5 on the backend and vue.js 2.5 on the frontend.
Live demo is available at: http://gambit.pellinen.ru/
git clone git@github.com:igronus/gambit.git
cd gambit
composer install
chown -R www-data:www-data storage
cp .env.example .env
php artisan cache:clear
php artisan key:generate
After that set up web-server to serve laravel or just run php artisan serve.
If you want to emulate devices, generate serialized array like this:
$devices = [
'DEVICE1' => 'http://your-domain.ru/emulate?device1',
'DEVICE2' => 'http://your-domain.ru/emulate?device2',
];
serialize($devices);
And put it into your .env file:
DEVICES='a:2:{s:7:"DEVICE1";s:37:"http://your-domain.ru/emulate?device1";s:7:"DEVICE2";s:37:"http://your-domain.ru/emulate?device2";}'
Command php artisan config:cache may need to be executed to clear application configuration cache.
NB: internal php artisan serve won't work while accessing http://127.0.0.1:8000/emulate by file_get_contents() function. So use real web server in this case.
If you want to increase/decrease number of requests to data feeds tune up downloader cache params in your .env file:
DOWNLOADER_CACHE=true
DOWNLOADER_CACHE_TIMEOUT=5
Run npm ci to install dependencies and npm run dev to build public/js/app.js.
If it doesn't work, check you have latest stable npm and node installed and do the following:
rm -rf node_modules package-lock.json
npm cache clear --force
npm install
TL;DR
### Problem description
TUF-2000M is an ultrasonic energy meter that has a [Modbus](https://en.wikipedia.org/wiki/Modbus) interface described in docs/tuf-2000m.pdf.
Gambit has access to one of these meters and it is providing you a [live text feed](http://tuftuf.gambitlabs.fi/feed.txt) that shows the time of the reading followed by the first 100 register values which look like this:
```
2017-01-11 19:12
1:7579
2:48988
3:5064
4:48142
5:37967
6:48877
7:63814
8:17575
9:0
10:0
11:24224
12:15965
13:0
14:0
15:0
16:0
17:87
18:0
19:9891
20:16221
21:65480
22:65535
23:39041
24:48994
25:0
26:0
27:0
28:0
29:144
30:0
31:48777
32:16191
33:15568
34:16611
35:28424
36:16534
37:7424
38:15783
39:14592
40:15758
41:5461
42:49087
43:45184
44:15493
45:36608
46:15459
47:29184
48:15516
49:0
50:0
51:0
52:0
53:6432
54:4386
55:5889
56:0
57:0
58:0
59:0
60:255
61:120
62:0
63:0
64:0
65:0
66:4001
67:62500
68:0
69:0
70:3
71:4
72:4
73:3606
74:16800
75:54913
76:48896
77:35706
78:17101
79:44042
80:17099
81:33339
82:16963
83:42500
84:49530
85:33468
86:16963
87:33210
88:16963
89:2885
90:16512
91:0
92:806
93:3501
94:3501
95:0
96:1
97:43137
98:17105
99:3374
100:17839
```
To help you on your way with data conversion I will give you a few clues based on the example data above:
- Register 21-22, Negative energy accumulator is -56.
- Register 33-34, Temperature #1/inlet is 7.101173400878906.
- Register 92, Signal Quality is 38.
The registers and their respective datatypes are explained in detail in [docs/tuf-2000m.pdf](https://github.com/gambit-labs/tuf-2000m/blob/master/docs/tuf-2000m.pdf) on pages 39-42.
### Your task
#### Option 1: Parsing the Modbus data
Create a program that parses the data, converts it to human readable data like integers, decimals and strings and presents it in a nice way. Depending on your skills and interests you can create a web service that will provide the conversion data, or you could even create a UI to visualize the data somehow, it is entirely up to you what you make of it!
#### Option 2: Web or native app
If the data conversion path in option 1 is not something that interests you, or you prefer a more graphical solution, create an app that retrieves and parses the data and presents it as is. The key point is to make use of data available in a backend, and present it in a mobile friendly way.
### Presenting your solution
Provide your solution as a Git repository, e-mail me the link to your private repo, or as a zip file and describe your solution either in the mail or using the README markdown. We appreciate if you can host your solution somewhere in the cloud so we can see an actual demo of it, rather than just looking at code.
There is no single solution to this problem, and we don't expect a complete solution to consider you for a position. Good use of Git version control is appreciated.
You can see a sketch below.
The main thing is backend module. It is responsible for getting data from text feeds (or in other format in the future), caching it for some time (to avoid unnecessary requests), storing it if needed and serving clients.
Let's describe how it should process, step by step.
1. Client 1 makes a request to a backend to get data.
2. Backend checks that there is no actual data in cache and gets it from feed.
3. Backend caches data in case of other clients requests.
4. Backend makes a response to Client 1 due to it's permissions.
5. Client 2 makes a request to a backend to get data.
6. Backend checks that there is actual data in cache and makes a response
to Client 2 due to it's permissions.
7. Client 3 makes a request to a backend to get data.
8. Backend checks that there is actual data in cache and makes a response
to Client 3 due to it's permissions.
The converter class is responsible for converting binaries into human-readable numbers. It uses binary string and it's internal type as arguments. See app/Converter.php file.
1. Be able to emulate file_get_contents() fails.
2. More accurate (close to previous data) emulation.
3. Show changes (mb colored) from previous data on frontend.
4. Make frontend more smooth.
5. Tests.
6. Backend authorisation.