@signalk/vedirect-serial-usb

vedirect-serial-usb

This code is a Signal K Node Server plugin. It reads and parses Victron VE.Direct data.

The common way to connect to a Victron product is with the Victron VE.Direct to USB interface cable. Alternatively, this plugin also supports receiving the data via UDP and on a TCP socket.

Compatible Victron products:

• BMV-700 series of Battery Monitors (reported to work also on the BMV-600)
• SmartShunt series of Battery Monitors
• SmartSolar Chargers
• BlueSolar Chargers
• Phoenix Inverters, including the Smarts, having a VE.Direct comms port

Note that above list may not be complete.

The TCP and UDP connection methods are to allow connecting to a Victron product too far away to run a serial cable. Ie. using a bridge to LAN/Wi-Fi that takes the serial data and makes it available on a TCP socket or sends it out as UDP packets. There are many of such devices available, as well as example DIY projects. A good example on how to make it yourself is explained here: https://pysselilivet.blogspot.com/2021/02/victron-vedirect-with-raspberry.html.

Lastly, note that when having a Victron GX Device, you won't be needing this plugin. Details for that here.

Installation

Use the Signal K app store or install via NPM in the Signal K server root directory: npm install @signalk/vedirect-serial-usb

Usage

Set up the appropriate device on the settings page of this plugin in the Signal K server admin UI, for instance to /dev/ttyUSB0 and enable the plugin. Your VE.Direct data will be available in Signal K format via various clients and apps.

Connections

Select device

• Serial, UDP or TCP

Connection details

• Serial: Enter device path e.g /dev/ttyUSB0
• UDP: ignored
• TCP: Enter host IP address

Port

• Serial: ignored
• UDP/TCP: port

Ignore Checksum

• If you want to ignore checksum, use this option. Default ON

SK Paths

• Give each device unique SK paths

BMV relay control

For BMV-7xx battery monitors on a serial connection, the built-in relay is exposed as a writable Signal K path so other plugins can switch it:

electrical.batteries.<bmv>.relay

where <bmv> is the BMV name configured for the connection. Send a PUT request with a value of 1/true to close the relay or 0/false to open it. The plugin reports an error if the value is out of range or the serial port is not open, rather than silently doing nothing.

The writable path exists only for a serial connection whose device type is a battery monitor (not a solar charger) and that has a BMV name configured; without a name there is nothing to anchor the path to, so no writable path is registered. A successful response means the command was written to the port, not that the relay is confirmed switched: the BMV sends no acknowledgement, and it acts on the command only when its relay is set to remote control on the BMV itself. Relay control is only available over serial, as it depends on writing back to the VE.Direct port.

Usage as a library

It's possible to use this plugin as a library, in other Node.js code. This feature simply wraps the plugin in an easy-to-consume manner, so functionality is identical. Example:

const VEDirect = require('@signalk/vedirect-serial-usb/standalone')
const consumer = new VEDirect({
  device: '/dev/ttyUSB0',
  ignoreChecksum: true,
  mainBatt: 'House',
  auxBatt: 'Starter',
  solar: 'Main'
})

consumer.on('delta', (delta) => console.log('[onDelta]', delta))
consumer.stop() // stop the plugin, destruct the connections
consumer.start() // (re-)start the plugin

License

Apache-2.0. See LICENSE.

Copyright 2018 Joachim Bakke, Fabian Tollenaar and Karl-Erik Gustafsson.