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https://github.com/njh/node-red-contrib-owfs

Node-RED node for talking to 1-wire devices using owfs
https://github.com/njh/node-red-contrib-owfs

1-wire javascript node-red owfs owserver

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Node-RED node for talking to 1-wire devices using owfs

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README 

        
node-red-contrib-owfs

=====================



A [Node-RED] node for talking to [1-wire] devices using an [owfs] [owserver] instance.



Install

-------



Run the following command in the root directory of your Node-RED install



    npm install node-red-contrib-owfs



Usage

-----



Install [owfs], either on the same system as Node-RED, or a system that can be reached over TCP. This node communicates with owfs using the owserver protocol - so owserver must be running.



One or more owfs paths can be selected in the node edit dialog. Upon receiving a message on the input the node, it will request each of the values in turn from owfs and places the reading in **msg.payload**.



Alternatively a device path can be specified in the **msg.topic** field, for example 28.0080BE21AA00/temperature. This will override any paths selected in the edit dialog.



In addition the owserver port and/or host can be specified in **msg.host** and **msg.port**, overriding any settings in the node configuration.



To trigger reading sensors periodically, use an Inject node to send messages every X seconds.



To check presence of sensors, select Mode **Presence** and use an Inject node to request the status. A boolean value in **msg.payload** will indicate the sensor presence status.



Example

-------



This example shows a simple flow to read a 1-wire temperature sensor using owfs and publish the reading to MQTT as a retained message.



![screenshot](https://github.com/njh/node-red-contrib-owfs/raw/master/screenshot.png)



In this flow, the inject node is used to specify the name of the 1-wire device to be read from, this triggers every 10 seconds. When the owfs node receives this message, it makes a query to owserver, running on the same machine. It takes a temperature reading and outputs the temperature value in msg.payload.



Then change node is used to set msg.retain to true - this causes MQTT to keep a copy of the latest temperature reading, so when a new client subscribes, it immediately gets a value.



The flow can be downloaded from the Node-Red Flow Library here:

http://flows.nodered.org/flow/b11cfe3a7728a297e44d



Hardare Tested

--------------



* [DS18B20 Temperature Sensor](http://www.maximintegrated.com/en/products/DS18B20)

* [DS9490R USB Host Adapter](http://www.maximintegrated.com/en/products/DS9490R)

* [RPI2: 1-Wire Host Adapter for Raspberry Pi](http://www.sheepwalkelectronics.co.uk/product_info.php?cPath=22&products_id=30)

* [SWE1: Temperature Sensor](http://www.sheepwalkelectronics.co.uk/product_info.php?cPath=23&products_id=53)

* [SWE3: Humidity Sensor Module](http://www.sheepwalkelectronics.co.uk/product_info.php?cPath=23&products_id=55)

* [SWE4: Dual Channel I/O Module](http://www.sheepwalkelectronics.co.uk/product_info.php?cPath=23&products_id=59)

* [DS1822 Econo 1-Wire Digital Thermometer](http://www.maximintegrated.com/en/products/DS1822)

* [DS2401 Silicon Serial Number](http://www.maximintegrated.com/en/products/DS2401)

* [DS2406 Dual Addressable Switch Plus 1Kb Memory](http://www.maximintegrated.com/en/products/DS2406)

* [DS2408 1-Wire 8-Channel Addressable Switch](http://www.maximintegrated.com/en/products/DS2408)

* [DS2438 Smart Battery Monitor](http://www.maximintegrated.com/en/products/DS2438) (often used as a temperature and humidity sensor)



[Node-RED]:  http://nodered.org/

[1-wire]:    http://www.maximintegrated.com/en/products/comms/one-wire.html

[owfs]:      http://owfs.org/

[owserver]:  http://owfs.org/index.php?page=owserver