Javascript Library for Marvelmind GPS
Marlvelmind.js includes two small Javascript classes for receiving and parsing data from Marvelmind mobile beacon by USB/serial port.
This code contains a CLIENT and a SERVER utility classes. Both classes read data using bufferpack and Marvelmind Instructions (v7.00). They apply a similar approach to read incoming data, but differ significantly on how data is received and parsed.
The client class is built upon WebUSB API, an experimental technology which, up to this date, is only supported by Chromium Based Browsers (Google Chrome, Edge, Opera, ...). On client, parsing incoming data chunks into readable message is performed by a custom parser.
The server class of this code uses a serial port library, serialport, to acquire data stream. On server, parsing is conviniently done with parser-delimiter.
Events are emitted using EventEmitter and native Node.js Events API for client and server classes, respectively.
Please, ensure that all deploying instructions by Marvelmind have been thoroughly followed. Remember to update all SW Firmware, setup Beacon positioning, turn them ON, adjust Maps and Submaps and connect the USB Modem on your computer. It's mandatory to install the STM32 Driver to get modem data via USB.
Note: Don't forget to ensure Marvelmind Dashboard is closed when testing this code - only one program (a Node.js server, a web browser or the Marvelmind Dashboard) is allowed to receive data stream from the USB Modem at a specific port and time.
Note 2: Some data stream are disabled by default. For example, quality and telemetry streams require that options “Quality and extended location data” and “Telemetry stream” are enabled, respectively. Visit the Dashboard, select a device and go under Interfaces to see more.
- Open /client/test.html
- Click on Connect GPS Modem
- Select the Marvelmind Modem.
- Incoming data will be logged on console. Enjoy!
- Verify the USB Serial port address used in your OS. This address may vary significantly on Windows, Linux and MacOS devices. Update it on the portAddress argument. For example, if your USB port address is COM3:
let marvelmind = new Marvelmind({portAddress:'COM3'})
- On the /server/ folder, run:
npm install npm run test
- Incoming data will be logged on console. Enjoy!
Both classes emit Events to transfer incoming data. Here follows a comprehensive list:
| Event String | Content | Marvelmind Code | Version |
|---|---|---|---|
| rawDistances | Beacon Distances (mm) | 0x0004 (4) | Both |
| telemetry | Battery (mV) and RSSI (Dbm) | 0x0006 (6) | Both |
| quality | Quality Parameter (%) and Geofencing Zone Index | 0x0007 (7) | Both |
| hedgehogMilimeter | Hedgehog Coordinates (mm) | 0x0011 (17) | Both |
| beaconsMilimeter | Beacons Coordinates (mm) | 0x0012 (18) | Both |
| connected | None | ----------- | Client Only |
| disconnected | None | ----------- | Client Only |
<script src="assets/js/bufferpack.js"></script>
<script src="assets/js/EventEmitter.js"></script>
<script src="marvelmind.js"></script>
<script>
let marvelmind = new Marvelmind();
marvelmind.on('hedgehogMilimeter', (hedgehogAddress, hedgehogCoordinates) => {
console.log(hedgehogAddress, hedgehogCoordinates);
});
marvelmind.toggleConnection(); //Requires user interaction first!
</script>
baudRate - baudrate. Should match baudrate of hedgehog-beacon.
Default value: 9600
debug - debug flag. Activates console output.
Default value: False
toggleConnection( ) - Toggle serial port connection.
Note: Modern browser policy requires that users interact with the site before allowing a WebUSB connection. For example, on /client/test.html, a click event is used to ensure user interaction.
const { Marvelmind } = require('./marvelmind');
const marvelmind = new Marvelmind();
marvelmind.on('hedgehogMilimeter', (hedgehogAddress, hedgehogCoordinates) => {
console.log(hedgehogAddress, hedgehogCoordinates);
});
portAddress - serial port device name (physical or USB/virtual). Default value: 'COM3'
- '/dev/ttyACM0' - typical for Linux
- '/dev/tty.usbmodem1451' - typical for Mac OS X
- 'COM3' to 'COM6' - typical for Windows
baudRate - baudrate. Should match baudrate of hedgehog-beacon.
Default value: 9600
debug - debug flag. Activates console output.
Default value: False
paused - pause flag. If true, instance will not read messages parsed from serial data when created. To start data reading, use toggleReading.
Default value: False
toggleReading( ) - Toggle data reading.
This repository is inspired by a former repository of Joshua J. Damanik which implemented Marvelmind data processing on Node.js. Additionally, some opinionated choices have been inspired by marvelmind.py for consistency.
Please reach murilohoias@gmail.com