bobaos-project

Raspberry Pi communication with KNX bus using Wienzierl BAOS 838 kBerry module.

bobaos-project

Hello, friend.

I would like to introduce you bobaos-project, JavaScript library implementing KNX ObjectServer Protocol for KNX BAOS Module 838 kBerry.

The main purpose of project is to bring modern JavaScript with it’s infrastructure into KNX and world of BAOS.

Installation

  • Prepare your Raspberry Pi: install raspbian, enable ssh. Or you could download my image here. In this case you should go directly to step 4. Image is based on 2017-11-29-raspbian-stretch-lite with installed nodejs 8, vim, git, enabled ssh and correct config.txt, cmdline.txt.
  • Install KNX BAOS Module 838 kBerry shield.
  • Set up serial port
  • Install nodejs, git
curl -sL https://deb.nodesource.com/setup_8.x | sudo -E bash - sudo apt-get install -y nodejs git
  • Clone this repository
git clone https://github.com/shabunin/bobaos.git
  • Install dependencies
cd bobaos/ 
npm install 

It will install all npm dependencies as serialport.

Running example

node example/example.js

In my case I have one temperature sensor(id 1, dpt9), LED brightness(id 2, dpt5).

We send requests at first

// send requests after successful initial reset 
app.on('open', () => { 
    app
       .getDatapointDescription(1, 10)
       .getParameterByte(1, 10)
       .readDatapointFromBus(1, 2) // good
       .readDatapointFromBus(1, 10) // error! 
       .getDatapointValue(1, 10)
       .setDatapointValue(2, Buffer.alloc(1, 0xc0))
       .getDatapointValue(2); 
});

And listen to responses

// listen to incoming events and responses 
app.on('service', console.log); 

The output should looks like this with disabled debug option

{ service: 'GetParameterByte.Res',
  error: false,
  start: 1,
  number: 10,
  payload: <Buffer 01 03 05 07 09 0b 0a 00 00 00> }
{ service: 'SetDatapointValue.Res',
  error: false,
  start: 1,
  number: 0,
  payload: null }
{ service: 'GetDatapointValue.Res',
  error: false,
  start: 1,
  number: 1,
  payload: [ { id: 1, state: 4, length: 2, value: <Buffer 0c fb> } ] }
  ....
  ....

For more details look at example/out_debug_*.log

The values in request/response are buffers and you should use some library to decode/encode values. I suggest knx-dpts-baos.

API

The communication between Host(RPi) and ObjectServer(Baos module) in this module implemented as request-event model. So, all requests should be send by provided methods as getDatapointDescription, etc and all response data should be handled by callback on ‘service’ event.

Currently, this module supports following methods:

getDatapointDescription(id, [number = 1]).

Get description for datapoints. Response includes value type(length), config flags, datapoint type.

Response example:

{ service: 'GetDatapointDescription.Res',
  direction: 'response',
  error: false,
  start: 1,
  number: 10,
  payload: 
    [ { id: 1, valueType: 8, configFlags: 95, dpt: 'dpt9' },
    { id: 2, valueType: 7, configFlags: 87, dpt: 'dpt5' },
    { id: 3, valueType: 7, configFlags: 87, dpt: 'dpt5' },
    { id: 4, valueType: 7, configFlags: 87, dpt: 'dpt5' },
    { id: 5, valueType: 7, configFlags: 87, dpt: 'dpt5' },
    { id: 6, valueType: 0, configFlags: 95, dpt: 'dpt1' },
    { id: 7, valueType: 0, configFlags: 95, dpt: 'dpt1' },
    { id: 8, valueType: 0, configFlags: 87, dpt: 'dpt1' },
    { id: 9, valueType: 0, configFlags: 87, dpt: 'dpt1' },
    { id: 10, valueType: 7, configFlags: 83, dpt: 'dpt5' } ] }

setDatapointValue(id, value)

Set and send datapoint value to bus. Value should be Buffer encoded.

Response example:

{ service: 'SetDatapointValue.Res',
  direction: 'response',
  error: false,
  start: 2,
  number: 0,
  payload: null }

readDatapointFromBus(id, length)

Send read request to KNX bus.

Response example:

{ service: 'SetDatapointValue.Res',
  direction: 'response',
  error: false,
  start: 1,
  number: 0,
  payload: null }

getDatapointValue(id, [number = 1])

Get datapoints value from baos.

Response example:

{ service: 'GetDatapointValue.Res',
  direction: 'response',
  error: false,
  start: 1,
  number: 10,
  payload: 
   [ { id: 1, state: 4, length: 2, value: <Buffer 0c fb> },
     { id: 2, state: 16, length: 1, value: <Buffer c0> },
     { id: 3, state: 16, length: 1, value: <Buffer 10> },
     { id: 4, state: 0, length: 1, value: <Buffer 00> } ] }

getParameterByte(id, [number = 1])

Get parameter bytes starting with id number.

Response example:

{ service: 'GetParameterByte.Res',
  direction: 'response',
  error: false,
  start: 1,
  number: 10,
  payload: <Buffer 01 03 05 07 09 0b 0a 00 00 00> }

Useful cases

  • DIY home controller: write your own scripts in JS, use rich npm infrastructure to integrate with different services
  • As a gateway to other systems. For example, you may use it with homebridge to add HomeKit support to your KNX bus.

Demo

My presentation at TADHack 2017

Apple HomeKit integration

TODO:

  • npm package
  • More services support

Source: bobaos-project

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