Monthly Archives: May 2019

Raspberry Pi – Headless Setup

It’s been some time since we wrote our earlier blog describing setting up a Raspberry Pi, and a lot has changed since, including the base operating system. Raspbian Stretch, the latest version of the Debian port for the Raspberry Pi has a lot of great new features and so it is time for an update.

In this blog, we are setting up a Pi in headless mode – that is to say we want it to work over the WiFi via an ssh session from a remote computer from the start – and don’t want to be plugging it into a monitor with a keyboard etc.

The first step is to visit the Raspberry Pi Downloads page. Here, we can either download the ‘Noobs’ installer, or as we will the full Raspbian image. Downloading the Raspbian image, there is a choice between a version with and without a set of recommended software packages installed, Python, Scratch, Sonic Pi, Java etc. Although that is a very useful facility, in this case, we wanted a clean version of Raspbian, so downloaded the file ‘2019-04-08-raspbian-stretch.img’ (the other image file would have ‘-full’ as a suffix. When the file is downloaded, it is a zip file. This is then unzipped to the ‘img’ file.

We now need to use the ‘Etcher’ tool to install the image on our new microSD card. Since last using etcher, we note there is also a new version of this excellent utility from Balena too. We inserted the MicroSD card into a USB reader, inserted into the laptop and ran Etcher. From here we select the image, the destination card and hit ‘Flash’. The image is copied to the card and verified.

The new Balena Etcher programme

Once the image is copied over, we need to make the edits to the new installation to make it work on out network. Using a MacBook laptop, we unplugged the USB reader, and then plugged it back in again. This led to a new volume ‘Boot’ being mounted – an icon appears on the desktop.

The MicroSD card, its USB reader – and for Mac users, the dongle to get the Mac to read the USB ‘A’ device (to USB ‘C’).

We opened a terminal and changed to the new volume:

cd /Volumes/boot

Now we need to add two things, a file in this location called ‘ssh’ to enable secure shell access, and secondly the WiFi credentials.

sudo touch ssh

and to create and edit the Wifi configuration file:

sudo nano wpa_supplicant.conf

In the new file, for Raspbian Stretch, we add the following:

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
 network={
     ssid="WIFI-SSID"
     psk="WIFI-PASSWORD"
     key_mgmt=WPA-PSK
 }
Inserting the MicroSD card in the Pi (already in its case)

The card is now ready to be inserted into the Pi, and the machine booted up for the first time. Hopefully, the Pi will authenticate correctly on the WiFi network.

We can check the Router utility to see what DHCP address the Pi was assigned, or run a command such as ‘ifconfig’ or ‘arp -a’ to inspect connected devices. In our case the IP address, on a local network, could be for example 192.168.1.100

We should now then be able to ssh onto the Pi

ssh pi@192.168.1.100

The default password is ‘raspberry’. Once we are logged in a few important things. First is to change the system password:

passwd

Next, update and upgrade the system (see link):

sudo apt-get update
sudo apt-get dist-upgrade

If necessary, raspi-config can be run to permit further configuration:

sudo raspi-config

We now have a functioning Raspberry Pi, ready for our next project.

BME680 and the Particle Photon

Introduction

Here at Cranfield University we are putting in place plans related to the new ‘Living Laboratory’ project, part of our ‘Urban Observatory’. This project sits within the wider UKCRIC initiative, across a number of universities. Of the many experiments in development, we are gathering environmental data from IoT devices and building data dashboards to show the data and related analyses. One of our projects will be to place environmental sensors in our lecture rooms and public spaces to allow our facilities team to monitor conditions across the campus. In this blog, we show how this project is starting to take shape, and in so doing explain how we are connecting the Particle Photon device up with Bosch’s amazing multifunction BME680 sensor.

The controller we use is the Particle Photon, described in an earlier post. We started with a device without header poles, and then soldered in the ones we will use [D0, D1, +ve, Gnd]. The Photon was then connected to the WiFi network, following the instructions on the particle website Quick Start Guide.

Hardware

Particle Photon

Next we used a Bosch BME680 sensor. This is able to measure temperature, pressure, humidity, and indoor air quality (IAQ) – the device currently returns gas resistivity in KOhms, rather than IAQ. It is also able to use the i2C interface, which only needs two connections, plus power (4 cables). Here the connection sockets are shown having been soldered in.

Bosch BME680 multi-function sensor



We then prepared four appropriate cables.

Cables

and then wired the devices up. The wiring connections used were:

PhotonBME680
D0SDA
D1SCL
3.3V2-6V
GNDGND













Code

Next, we opened the Particle Photon oneline cloud Web IDE. We created a new app, and located the Adafruit BME680 library and sample code.

The full code is presented below.

/***************************************************************************
  This is a library for the BME680 gas, humidity, temperature & pressure sensor
  Designed specifically to work with the Adafruit BME680 Breakout
  ----> http://www.adafruit.com/products/3660
  These sensors use I2C or SPI to communicate, 2 or 4 pins are required
  to interface.
  Adafruit invests time and resources providing this open source code,
  please support Adafruit and open-source hardware by purchasing products
  from Adafruit!
  Written by Limor Fried & Kevin Townsend for Adafruit Industries.
  BSD license, all text above must be included in any redistribution
 ***************************************************************************/

#include "Adafruit_BME680.h"

#define BME_SCK 13
#define BME_MISO 12
#define BME_MOSI 11
#define BME_CS 10

#define SEALEVELPRESSURE_HPA (1013.25)

Adafruit_BME680 bme; // I2C
//Adafruit_BME680 bme(BME_CS); // hardware SPI
//Adafruit_BME680 bme(BME_CS, BME_MOSI, BME_MISO,  BME_SCK);

double temperatureInC = 0;
double relativeHumidity = 0;
double pressureHpa = 0;
double gasResistanceKOhms = 0;
double approxAltitudeInM = 0;

void setup() {
   
  if (!bme.begin(0x76)) {
    Particle.publish("Log", "Could not find a valid BME680 sensor, check wiring!");
  } else {
    Particle.publish("Log", "bme.begin() success =)");
    // Set up oversampling and filter initialization
    bme.setTemperatureOversampling(BME680_OS_8X);
    bme.setHumidityOversampling(BME680_OS_2X);
    bme.setPressureOversampling(BME680_OS_4X);
    bme.setIIRFilterSize(BME680_FILTER_SIZE_3);
    bme.setGasHeater(320, 150); // 320*C for 150 ms

    Particle.variable("temperature", &temperatureInC, DOUBLE);
    Particle.variable("humidity", &relativeHumidity, DOUBLE);
    Particle.variable("pressure", &pressureHpa, DOUBLE);
    Particle.variable("gas", &gasResistanceKOhms, DOUBLE);
    Particle.variable("altitude", &approxAltitudeInM, DOUBLE);
  }
}

void loop() {
  if (! bme.performReading()) {
    Particle.publish("Log", "Failed to perform reading :(");
  } else {
    temperatureInC = bme.temperature;
    relativeHumidity = bme.humidity;
    pressureHpa = bme.pressure / 100.0;
    gasResistanceKOhms = bme.gas_resistance / 1000.0;
    approxAltitudeInM = bme.readAltitude(SEALEVELPRESSURE_HPA);

    // ThingSpeak Channel Info                        
    unsigned long myChannelNumber =999999;      //  From your ThingSpeak Account Info
    const char * myWriteAPIKey = "YOURAPIKEY";  //  From your ThingSpeak Account Info (API KEYS tab)

    String data = String::format(
      "{"
        "\"temperatureInC\":%.2f,"
        "\"humidityPercentage\":%.2f,"
        "\"pressureHpa\":%.2f,"
        "\"gasResistanceKOhms\":%.2f,"
        "\"approxAltitudeInM\":%.2f,"
        "\"key\":\"%s\""
      "}",
      temperatureInC,
      relativeHumidity,
      pressureHpa,
      gasResistanceKOhms,
      approxAltitudeInM,
      myWriteAPIKey);

    Particle.publish("Sensor", data, 60, PRIVATE, NO_ACK);
  
  }
  delay(10 * 1000);
}

Receiving data

Note the inclusion of the ThingsBoard API key ‘myWriteAPIKey’ into the JSON structure. ThingsBoard is used below.

Once we verified and flashed this code to the new Photon, it was able to start generating data. It took about 20 minutes to stabilise readings. Data was then picked up from the Particle.publish command in the source code on the Particle Console view. The data JSON structure is shown being generated (key not shown).

Particle Console

ThingSpeak Dashboard

Finally, following the approach outlined in this earlier blog, we built a ‘Webhook’ integration from the Particle web Console to ThingSpeak, and added a new Channel to receive the data to create a dashboard.

ThingsSpeak Dashboard – data shown with spline and averaged over 10 minutes

and as before the range of visualisations can be customised, and indeed the power of Matlab analytics can be blended in also.

Alternate dashboard with gauges

Epilogue

This blog has shown how easy it is to get a Particle Photon working with a Bosch BME680 multifunction sensor. As can be seen, the sensor outputs a range of data streams, barometric pressure, humidity, temperature and gas, and of these it is the gas resistance level, from which an Indoor Air Quality (IAQ) can be calculated, that is of particular interest. To quote Bosch, ‘The gas sensor within the BME680 can detect a broad range of gases to measure indoor air quality for personal well being. Gases that can be detected by the BME680 include: Volatile Organic Compounds (VOC) from paints (such as formaldehyde), lacquers, paint strippers, cleaning supplies, furnishings, office equipment, glues, adhesives and alcohol.’ This opens up a range of applications for this sensor which, combined with our project to monitor continuously public areas around the campus, a lot of options. As the Bosch technical sheet notes, IAQ provides a value from 0-500, with the following classification:

IAQ IndexAir Quality
0 – 50good
51 – 100average
101 – 150little bad
151 – 200bad
201 – 300worse
301 – 500very bad

The current device and software library only returns gas resistance, but a future project can be to link this to the Bosch libraries that calculate IAQ. There is also an interesting thread on the Pi Moroni blog for achieving this oneself, and more information here also.

Node-RED and the Internet of Things

Here at Cranfield University we are putting in place plans related to the new ‘Living Laboratory’ project, part of our ‘Urban Observatory’. This project sits within the wider UKCRIC initiative, across a number of universities. Of the many experiments in development, we are gathering environmental data from IoT devices and building data dashboards to show the data and related analyses.

In this blog we investigate the use of Node-RED (https://nodered.org) as a programming tool for wiring together hardware devices, APIs and online services, using its browser-based editor to wire together flows using the wide range of nodes in the palette that can be deployed to its runtime in a single-click. Node-RED provides graphical programming tool for Node-JS that permits complex programs to be built pictorially with great ease. To undertake the project, we used a WIO Node device collecting temperature values, exposing these values via a web service, and the Node-RED receiving device being a Raspberry Pi.

Sourcing temperature data – the Wio Node

The Wio Node temperature sensor was described in an earlier blog here (http://www.geothread.net/voice-activated-wio-node-temperature-sensor). Temperature values are extracted via a web-based API call, with the REST URL taking the form, thus:

https://us.wio.seeed.io/v1/node/GroveTemp1WireD1/temp?access_token=TOKEN_GOES_HERE

The temperature values are then returned as a JSON string, appearing thus:

{"temperature":19.1800000000001}

Preparing the Raspberry Pi – installing Node-RED

To prepare the Raspberry Pi and install Node-RED, we first followed instructions to install Node-JS on the Pi at https://www.w3schools.com/nodejs/nodejs_raspberrypi.asp. Next we followed the instructions on the Node-RED site (https://nodered.org/docs/hardware/raspberrypi). In brief, we ran the Node-RED upgrade script:

bash <(curl -sL https://raw.githubusercontent.com/node-red/raspbian-deb-package/master/resources/update-nodejs-and-nodered)

We then set Node-RED to start automatically on boot, with:

sudo systemctl enable nodered.service

Running Node-RED

The Raspberry Pi was then rebooted. We were then able to start using the Node-RED editor (https://nodered.org/docs/hardware/raspberrypi#using-the-editor), calling the web-based interface with the URL (the IP address being that if the Raspberry Pi):

http://{the-ip-address-returned}:1880/

The general Node-RED interface, ‘palette’ to the left, properties to the right, and design canvas centrally.

Node-RED allows installation of many modules, one of which permits data dashboards. The data dashboard module is described at https://flows.nodered.org/node/node-red-dashboard. Installation can be via npm, as described at the link above. However, we used the ‘Manage Palette’ option within the graphical interface to install the new functions.

With this installed, the next task was to develop the ‘flow’, or programme. This starts with a HTTP GET call to the WIO Node as described above. For this the ‘http request’ node is called, and configured with the URI to the temperature value. After consideration of the various configuration options, we elected to return a ‘parsed JSON object’.

To drive the process whereby the URI is called continuously, the http request call is preceded with an ‘inject node’, set to run continuously on a timed basis (shown here at 5 seconds, although that could be a longer period).

The data that is returned from this process, the ‘payload’, can now be passed directly to the first element of the dashboard – the gauge. The payload JSON object has a member ‘temperature’, referenced via the value format {{payload.temperature}}.

The next dashboard elements we wanted are firstly a line graph of temperature over time, and secondly a custom node recording the ‘minimum’ and ‘maximum’ temperatures over time. These nodes will need data prepared in a particular way. The graph, or chart, needs data in the form described at https://github.com/node-red/node-red-dashboard/blob/master/Charts.md.

{topic:"temperature", payload:22}

In addition, further JSON elements for minimum and maximum values will be required. In order to construct a revised message payload, a custom script is required. Explanations are in the code below:

// Create a new empty object 'newMsg' to return at the end
// then fill it with another empty object 'bounds'
var newMsg={bounds:{}}; // create

// Create two local variables min and max initialised from the persistent 
// context variables of the same names where these values exist, or else
// seed with values we know are off the scale
var min=context.get('min') || 100;
var max=context.get('max') || -100;

// Set an element 'topic' and give the value the string 'temperature'
newMsg.topic = 'temperature';
// Set the payload element to the incoming message payload temperature
newMsg.payload = msg.payload.temperature

// update the min and max, comparing the incoming values to the context
if (msg.payload.temperature < min) {
   newMsg.bounds.min = msg.payload.temperature;
   context.set('min', msg.payload.temperature);
} else {
   newMsg.bounds.min = min;
}
if (msg.payload.temperature > max) {
   newMsg.bounds.max = msg.payload.temperature;
   context.set('max', msg.payload.temperature);
} else {
   newMsg.bounds.max = max;
}

// and finally return the new object 'newMsg'
return newMsg;

What is always a good idea when processing data is to have a debug that shows the whole message object constructed by this process. To do this, a ‘debug node’ is added and configured – here to show the ‘complete msg object’. We can see the min and max are contained in the bounds node, and that the ‘topic’ and ‘payload’ elements are correctly configured.

As a result, the two additional dashboard node widgets can be added, first the chart node. The line interpolation is set here to ‘bezier’ to provide a smoother visualisation. The time interval is set to 15 minutes.

Next we wanted to add a new custom node widget to show a running maximum and minimum value. To do this, we added a ‘Template node’ and configured it thus:

<div layout="row" layout-align="start center">
  <span flex>Temp Min: </span>
  <span flex>Temp Max: </span>
</div>
<div layout="row" layout-align="start center" ng-repeat="bounds in msg">
  <span flex style="color: green">{{bounds.min}}</span>
  <span flex style="color: red">{{bounds.max}}</span>
</div>

Once these elements are all in place, the ‘flow’ programme can be deployed. This commences the running of the code, and then the dashboard can be accessed. The easiest means to do this is to follow the link in the properties section as shown:

The result is the display of the dashboard. To get this to display as required, one can change the visual style (e.g. to ‘dark’), and the dimensions of the canvas. Node dashboard widgets are always rendered to the top left according to the layout properties.

Epilogue

In this blog, we have shown how the Node-RED environment can be used to streamline Node-JS code, with customised elements, and inclusion of libraries of functionality (dashboard). Node-RED is a powerful yet easy to configure environment that is cable of a whole range of functionality though its graphical ‘flows’. There are many example flows available on websites that can be downloaded and tested. Flows are designed to be easily imported and exported. Below is the export for the flow described above – to load it, select ‘Import’ and ‘Clipboard’ from the main menu options and paste in the following.

<div layout="row" layout-align="start center">[{"id":"d988539b.52bdc8","type":"tab","label":"Temperature","disabled":false,"info":""},{"id":"35963a2e.6aa056","type":"tab","label":"Temperature","disabled":false,"info":""},{"id":"166841a0.b19cce","type":"mqtt-broker","z":"","broker":"192.168.0.6","port":"1883","clientid":"Teste","usetls":false,"compatmode":true,"keepalive":"60","cleansession":true,"birthTopic":"","birthQos":"0","birthPayload":"","willTopic":"","willQos":"0","willPayload":""},{"id":"a76a54d5.4c5998","type":"ui_tab","z":"d988539b.52bdc8","name":"ESP_DTH11","icon":"dashboard","order":3,"disabled":false,"hidden":false},{"id":"519167a8.570e5","type":"ui_group","z":"d988539b.52bdc8","name":"DHT11","tab":"a76a54d5.4c5998","order":1,"disp":true,"width":"12","collapse":false},{"id":"1785bc54.de4d24","type":"ui_base","theme":{"name":"theme-dark","lightTheme":{"default":"#0094CE","baseColor":"#0094CE","baseFont":"-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen-Sans,Ubuntu,Cantarell,Helvetica Neue,sans-serif","edited":true,"reset":false},"darkTheme":{"default":"#097479","baseColor":"#097479","baseFont":"-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen-Sans,Ubuntu,Cantarell,Helvetica Neue,sans-serif","edited":true,"reset":false},"customTheme":{"name":"Untitled Theme 1","default":"#4B7930","baseColor":"#4B7930","baseFont":"-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen-Sans,Ubuntu,Cantarell,Helvetica Neue,sans-serif"},"themeState":{"base-color":{"default":"#097479","value":"#097479","edited":false},"page-titlebar-backgroundColor":{"value":"#097479","edited":false},"page-backgroundColor":{"value":"#111111","edited":false},"page-sidebar-backgroundColor":{"value":"#000000","edited":false},"group-textColor":{"value":"#0eb8c0","edited":false},"group-borderColor":{"value":"#555555","edited":false},"group-backgroundColor":{"value":"#333333","edited":false},"widget-textColor":{"value":"#eeeeee","edited":false},"widget-backgroundColor":{"value":"#097479","edited":false},"widget-borderColor":{"value":"#333333","edited":false},"base-font":{"value":"-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Oxygen-Sans,Ubuntu,Cantarell,Helvetica Neue,sans-serif"}},"angularTheme":{"primary":"indigo","accents":"blue","warn":"red","background":"grey"}},"site":{"name":"Node-RED Dashboard","hideToolbar":"false","allowSwipe":"false","lockMenu":"false","allowTempTheme":"true","dateFormat":"DD/MM/YYYY","sizes":{"sx":48,"sy":48,"gx":6,"gy":6,"cx":6,"cy":6,"px":0,"py":0}}},{"id":"749056a0.0a1d28","type":"ui_group","z":"","name":"Chart","tab":null,"order":2,"disp":true,"width":"12","collapse":false},{"id":"684a7caa.4db0f4","type":"ui_group","z":"","name":"Chart","tab":"a76a54d5.4c5998","order":2,"disp":true,"width":"12","collapse":false},{"id":"84ea1128.ec6fd","type":"ui_tab","z":"35963a2e.6aa056","name":"ESP_DTH11","icon":"dashboard","order":3,"disabled":false,"hidden":false},{"id":"c86b0ed1.65efc8","type":"ui_group","z":"35963a2e.6aa056","name":"DHT11","tab":"84ea1128.ec6fd","order":1,"disp":true,"width":"12","collapse":false},{"id":"a7d331dd.9d8078","type":"debug","z":"d988539b.52bdc8","name":"Message object","active":true,"tosidebar":true,"console":true,"tostatus":false,"complete":"true","targetType":"full","x":1129.75,"y":286.9166564941406,"wires":[]},{"id":"aa810265.1f789","type":"ui_gauge","z":"d988539b.52bdc8","name":"Gauge","group":"519167a8.570e5","order":0,"width":"6","height":"2","gtype":"gage","title":"Temperature","label":"Celsius","format":"{{payload.temperature}}","min":0,"max":"60","colors":["#00b500","#e6e600","#ca3838"],"seg1":"25","seg2":"28","x":1086.833251953125,"y":432.8055419921875,"wires":[]},{"id":"aa922201.f96eb8","type":"inject","z":"d988539b.52bdc8","name":"","topic":"","payload":"","payloadType":"date","repeat":"","crontab":"","once":true,"onceDelay":0.1,"x":401.5,"y":394,"wires":[["cbeca854.f6174"]]},{"id":"cbeca854.f6174","type":"http request","z":"d988539b.52bdc8","name":"Wio Temperature","method":"GET","ret":"obj","paytoqs":false,"url":"https://us.wio.seeed.io/v1/node/GroveTemp1WireD1/temp?access_token=7c6297dfa2e48793c58a53269bc23ef0","tls":"","proxy":"","authType":"basic","x":610.5,"y":394,"wires":[["aa810265.1f789","cd69dcd.1c5d3a"]]},{"id":"af52c259.fecbd8","type":"ui_chart","z":"d988539b.52bdc8","name":"Chart","group":"684a7caa.4db0f4","order":2,"width":"12","height":"7","label":"Temperature chart","chartType":"line","legend":"true","xformat":"HH:mm:ss","interpolate":"bezier","nodata":"","dot":false,"ymin":"","ymax":"","removeOlder":"15                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               ","removeOlderPoints":"50","removeOlderUnit":"60","cutout":0,"useOneColor":false,"colors":["#1f77b4","#aec7e8","#ff7f0e","#2ca02c","#98df8a","#d62728","#ff9896","#9467bd","#c5b0d5"],"useOldStyle":false,"outputs":1,"x":1087.8333740234375,"y":384.22222900390625,"wires":[[]]},{"id":"cd69dcd.1c5d3a","type":"function","z":"d988539b.52bdc8","name":"Process temperature","func":"var newMsg={bounds:{}};\nvar min=context.get('min') || 100;\nvar max=context.get('max') || -100;\n\n// http://www.steves-internet-guide.com/node-red-variables/\nnewMsg.topic = 'temperature';\nnewMsg.payload = msg.payload.temperature\n\nif (msg.payload.temperature &lt; min) {\n   newMsg.bounds.min = msg.payload.temperature;\n   context.set('min', msg.payload.temperature);\n} else {\n   newMsg.bounds.min = min;\n}\nif (msg.payload.temperature &gt; max) {\n   newMsg.bounds.max = msg.payload.temperature;\n   context.set('max', msg.payload.temperature);\n} else {\n   newMsg.bounds.max = max;\n}\n\nreturn newMsg;","outputs":1,"noerr":0,"x":875.5,"y":336,"wires":[["af52c259.fecbd8","a7d331dd.9d8078","81bda4f5.6f104"]]},{"id":"259fa218.53bdbe","type":"comment","z":"d988539b.52bdc8","name":"Useful links","info":"see:\nhttps://github.com/node-red/node-red-dashboard/blob/master/Charts.md\nhttp://noderedguide.com/tutorial-node-red-dashboards-multiple-lines-on-a-chart/#more-1612\nhttp://www.steves-internet-guide.com/node-red-functions/\nhttp://www.steves-internet-guide.com/node-red-dashboard/","x":400.5,"y":337,"wires":[]},{"id":"81bda4f5.6f104","type":"ui_template","z":"d988539b.52bdc8","group":"519167a8.570e5","name":"Max and Min","order":2,"width":"6","height":"2","format":"</p><div layout="\&quot;row\&quot;" layout-align="\&quot;start" center\"="">\n  <span flex="">Temp Min: </span>\n  <span flex="">Temp Max: </span>\n</div>
<p>\n</p><div layout="\&quot;row\&quot;" layout-align="\&quot;start" center\"="" ng-repeat="\&quot;bounds" in="" msg\"="">\n  <span flex="" style="\&quot;color:" green\"="">{{bounds.min}}</span>\n  <span flex="" style="\&quot;color:" red\"="">{{bounds.max}}</span>\n</div>
<p>\n","storeOutMessages":true,"fwdInMessages":true,"templateScope":"local","x":1109.4444122314453,"y":336.6666717529297,"wires":[[]]},{"id":"f5bb5785.45e55","type":"debug","z":"35963a2e.6aa056","name":"Message object","active":true,"tosidebar":true,"console":true,"tostatus":false,"complete":"true","targetType":"full","x":1129.75,"y":286.9166564941406,"wires":[]},{"id":"27187c33.85c07c","type":"ui_gauge","z":"35963a2e.6aa056","name":"Gauge","group":"c86b0ed1.65efc8","order":0,"width":"6","height":"2","gtype":"gage","title":"Temperature","label":"Celsius","format":"{{payload.temperature}}","min":0,"max":"60","colors":["#00b500","#e6e600","#ca3838"],"seg1":"25","seg2":"28","x":1086.833251953125,"y":432.8055419921875,"wires":[]},{"id":"cd94fffc.6f0da8","type":"inject","z":"35963a2e.6aa056","name":"","topic":"","payload":"","payloadType":"date","repeat":"","crontab":"","once":true,"onceDelay":0.1,"x":401.5,"y":394,"wires":[["ab8d1686.0264d"]]},{"id":"ab8d1686.0264d","type":"http request","z":"35963a2e.6aa056","name":"Wio Temperature","method":"GET","ret":"obj","paytoqs":false,"url":"https://us.wio.seeed.io/v1/node/GroveTemp1WireD1/temp?access_token=&lt;<your token="" here="">&gt;","tls":"","proxy":"","authType":"basic","x":610.5,"y":394,"wires":[["27187c33.85c07c","ce9f0009.faab98"]]},{"id":"dbe1013a.863be8","type":"ui_chart","z":"35963a2e.6aa056","name":"Chart","group":"684a7caa.4db0f4","order":2,"width":"12","height":"7","label":"Temperature chart","chartType":"line","legend":"true","xformat":"HH:mm:ss","interpolate":"bezier","nodata":"","dot":false,"ymin":"","ymax":"","removeOlder":"15                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                               ","removeOlderPoints":"50","removeOlderUnit":"60","cutout":0,"useOneColor":false,"colors":["#1f77b4","#aec7e8","#ff7f0e","#2ca02c","#98df8a","#d62728","#ff9896","#9467bd","#c5b0d5"],"useOldStyle":false,"outputs":1,"x":1087.8333740234375,"y":384.22222900390625,"wires":[[]]},{"id":"ce9f0009.faab98","type":"function","z":"35963a2e.6aa056","name":"Process temperature","func":"var newMsg={bounds:{}};\nvar min=context.get('min') || 100;\nvar max=context.get('max') || -100;\n\nnewMsg.topic = 'temperature';\nnewMsg.payload = msg.payload.temperature\n\nif (msg.payload.temperature &lt; min) {\n   newMsg.bounds.min = msg.payload.temperature;\n   context.set('min', msg.payload.temperature);\n} else {\n   newMsg.bounds.min = min;\n}\nif (msg.payload.temperature &gt; max) {\n   newMsg.bounds.max = msg.payload.temperature;\n   context.set('max', msg.payload.temperature);\n} else {\n   newMsg.bounds.max = max;\n}\n\nreturn newMsg;","outputs":1,"noerr":0,"x":875.5,"y":336,"wires":[["dbe1013a.863be8","f5bb5785.45e55","b809b11b.7f47c8"]]},{"id":"b809b11b.7f47c8","type":"ui_template","z":"35963a2e.6aa056","group":"c86b0ed1.65efc8","name":"Max and Min","order":2,"width":"6","height":"2","format":"</your></p><div layout="\&quot;row\&quot;" layout-align="\&quot;start" center\"="">\n  <span flex="">Temp Min: </span>\n  <span flex="">Temp Max: </span>\n</div>
<p>\n</p><div layout="\&quot;row\&quot;" layout-align="\&quot;start" center\"="" ng-repeat="\&quot;bounds" in="" msg\"="">\n  <span flex="" style="\&quot;color:" green\"="">{{bounds.min}}</span>\n  <span flex="" style="\&quot;color:" red\"="">{{bounds.max}}</span>\n</div>
<p>\n","storeOutMessages":true,"fwdInMessages":true,"templateScope":"local","x":1109.4444122314453,"y":336.6666717529297,"wires":[[]]}]