GM1356 for Linux

Description

This driver was written for Digital Sound Level Meter with USB (type GM1356) serial number: HA:1303162 ordered from China via Aliexpress. My sonometer works with SoundLab Sound Level Meter v. 1.0.0.20, build 2016-07-20 delivered by Benetech Poland (thank you very much for this). I was trying to run it with SoundLab downloaded from Bogen website, but it couldn't connect to the device. It means my driver may not work with some GM1356 devices.

Installation

First make sure you have ruby interpreter installed. Then run:

gem install gm1356

Now make sure that users have access to your device. In my case I had to create /etc/udev/rules.d/90-usbpermission.rules with such content:

Then run:

```sudo udevadm control --reload```

And after all reconnect your device if it was already connected.

## Usage
If you want to print real time data from your sonometer, run:

```gm1356```

For more options:

```gm1356 --help```

## Protocol
I used Wireshark with USBPcap to sniff communication between my device and SoundLab on Windows in order to understend the protocol. Protocol is described in [PROTOCOL.md](PROTOCOL.md).

## Supported functionalities
* receiving real time data with `sound level value`, `A/C filter`, `max mode`, `slow/fast mode` and `measured range`
* changing `A/C filter`, `max mode`, `slow/fast mode` and `measured range`

## Unsupported functionalities
* importing recorded data