Save groov trend data to a CSV file on the AR1


Edit by @Beno. Clearly you can not just keep saving the trend data to the groov Box over and over forever.
Firstly because it is already stored in the trend, so it is not a backup of any kind and secondly because there is a limit to the amount of data you can store on the hard drive.
Please consider using the second flow in this thread, sending trend data to an email address as a CSV attachment.

Thanks to Mary’s post on how to get a URL to download chart data, and a little use of curl, you can build a flow that will regularly save trend data from the localhost groov server onto the AR1’s filesystem in CSV format!

Every week (the maximum period a trend will store) this flow injects, sets the URL, gets the CSV data with curl -k in an exec node, then uses JavaScript to set the filename field.
The function node grabs the timestamps from the first and last entries , stored in epoch format, converts them to ISO format and trims off seconds and miliseconds, then stitches them together with the string --to--, appends .csv to the end, and gives the file node that string for the filename.
In my case this gave me 2017-08-16T21:53--to--2017-08-18T21:53.csv for my 48 hour trend so I know what time period the CSV file covers. In application I would increase the inject to save this file once every two days since that is the length of my trend.
Once the flow has built a filename it uses the file node to permanently save the data to a CSV file in /home/dev.

To get the URL I strongly recommend reading Mary’s post to ensure that Node-RED can use your URL, since the exec node does not have administrator or editor privileges on its own.
An easy way to get the URL that meets the requirements she goes over is to log in as an admin user and right click the download 'tag' link in the trend display, and copy that link address to your clipboard.

Before you run the node you will need to edit the URL string and replace your groov box hostname, for example, with so that the exec node correctly resolves to the localhost. In the case of Mary’s post she would use the URL string

You are free to have this inject as often or rarely as you would like to store the trend data, so for a 48 hour trend like me you can change it to inject once every two days, or take off the timer and just manually click inject when you want to download the data, it’s totally up to you – feel free to modify this flow to suit your needs.

Happy coding!

[{“id”:“4df4c09d.ef9d5”,“type”:“file”,“z”:“e7108e55.3fa88”,“name”:"",“filename”:"",“appendNewline”:false,“createDir”:false,“overwriteFile”:“true”,“x”:710,“y”:1560,“wires”:[]},{“id”:“a273d3b0.d0b8”,“type”:“exec”,“z”:“e7108e55.3fa88”,“command”:“curl -k”,“addpay”:true,“append”:"",“useSpawn”:“false”,“timer”:"",“oldrc”:false,“name”:"",“x”:370,“y”:1540,“wires”:[[“2a64887f.c5d1b8”],[“32fdec2.a463514”],[“32fdec2.a463514”]]},{“id”:“efaf4f3c.34f23”,“type”:“inject”,“z”:“e7108e55.3fa88”,“name”:“inject 1/week”,“topic”:"",“payload”:"",“payloadType”:“date”,“repeat”:“604800”,“crontab”:"",“once”:false,“x”:220,“y”:1500,“wires”:[[“1a563f2e.bc32a1”]]},{“id”:“32fdec2.a463514”,“type”:“debug”,“z”:“e7108e55.3fa88”,“name”:"",“active”:false,“console”:“false”,“complete”:“true”,“x”:510,“y”:1560,“wires”:[]},{“id”:“1a563f2e.bc32a1”,“type”:“function”,“z”:“e7108e55.3fa88”,“name”:“set logging url”,“func”:"// ALWAYS change “host name” to “” and leave the rest of the string the same.\nreturn { payload : “” };",“outputs”:1,“noerr”:0,“x”:220,“y”:1540,“wires”:[[“a273d3b0.d0b8”]]},{“id”:“2a64887f.c5d1b8”,“type”:“function”,“z”:“e7108e55.3fa88”,“name”:“filename = “trend-start”–to–“trend-end””,“func”:“start = msg.payload.indexOf(”\\n");\nend = msg.payload.indexOf(",", start+1);\nmsg.first_stamp = parseInt(msg.payload.substring(start+1, end));\n // for UTC-7:00 timestamp offset: <(parseInt(…(…)) - 73600000)>\n \nf = new Date(msg.first_stamp);\nend = msg.payload.lastIndexOf(",");\nstart = msg.payload.lastIndexOf("\\n",end-1);\nl = new Date(parseInt(msg.payload.substring(start+1, end)));\n // for UTC-7:00 timestamp offset: <(parseInt(…(…)) - 73600000)>\n \nmsg.filename = f.toISOString().substring(0,16) + ‘–to–’ + l.toISOString().substring(0,16) + “.csv”;\n// filename = “yyyy-mm-ddThh:mm_to_yyyy-mm-ddThh:mm” trend start date_to_trend end date\nreturn msg;",“outputs”:1,“noerr”:0,“x”:610,“y”:1520,“wires”:[[“4df4c09d.ef9d5”]]}]


Instead of saving data to your groov box hard drive you can also use Node-RED to email trend data to any address or addresses you want as an attached CSV file.
Using groov read nodes you can also make gadgets to set exactly which tag to send, and have a send button on a groov page, with no further interaction with Node-RED! Here’s the flow I have to send either temperature, humidity, or solar radiation trend data to my email:

Where these are the relevant tags I have set up in my WeatherData groov data store:

With a groov page that has a 48 hour trend gadget plotting temp_f_flt, rel_humidity_int, and solar_rad_int, as well as an indicator button for sendFlag and a text box for sendTag:

Once every second the flow scans the boolean sendFlag into msg.payload, uses rate-by-exception to see if it has been toggled, then if msg.payload == true the button must have been turned on.
When that occurs Node-RED then reads the data store value in sendTag and uses it to build a download URL which gets the CSV data from the given trend using curl, takes the first and last epoch timestamps to build a file name and email body that records the time range of the data, then sends the email off while writing the sendFlag boolean button back to false so another trend can be sent.

It is important to note that using this tag field method, the tags must be in the same trend.
Take a look at these two URLS:

See that both use the tag 94, temperature, but the rest of the logging field is different. 2880_120 is the 48 hour tag, and 10080_300 is a week long trend. You could also enter these in another field, or just build a different flow and set of sendFlag / sendTag gadgets for each trend.

So for this flow I can freely enter 88 for humidity, 87 for solar radiation, or 94 to get Fahrenheit temperature from the 48 hour trend, where each is referenced by the Tag ID number in the groov data store. If an invalid tag ID is entered, the catch node overwrites -1 to the tag ID to let you know it didn’t work, and resets the toggle button.

Once a tag is entered I can send the tag using the toggle button and have the file emailed to any account I enter into the email node, or using the to, cc, or bcc fields in the attachment function node.

Happy coding!

[{"id":"f0389641.737b28","type":"exec","z":"e7108e55.3fa88","command":"curl -k","addpay":true,"append":"","useSpawn":"false","timer":"","oldrc":false,"name":"","x":550,"y":1260,"wires":[["83678c51.86334"],["2651a91f.e93666"],["2651a91f.e93666"]]},{"id":"2651a91f.e93666","type":"debug","z":"e7108e55.3fa88","name":"","active":false,"console":"false","complete":"true","x":710,"y":1260,"wires":[]},{"id":"6f3b4317.043b8c","type":"function","z":"e7108e55.3fa88","name":"set logging url","func":"// ALWAYS change \"host name\" to \"\" and leave the rest of the string the same.\nreturn {\n payload : \"\"+msg.sendTag+\n \"_0_2880_120_false/scanned-data.csv?api_key=3rWGiMK6ARtxk7AXEY4cXhGByCcAZAGK\",\n sendTag : msg.sendTag\n};","outputs":1,"noerr":0,"x":520,"y":1220,"wires":[["f0389641.737b28"]]},{"id":"83678c51.86334","type":"function","z":"e7108e55.3fa88","name":"attachment","func":"start = msg.payload.indexOf(\"\\n\");\nend = msg.payload.indexOf(\",\", start+1);\nf = new Date(parseInt(msg.payload.substring(start+1, end))- 7*3600000);\n // for UTC-7:00 timestamp offset: <(parseInt(..(..)) - 7*3600000)>\nfirst = f.toISOString();\n \nend = msg.payload.lastIndexOf(\",\");\nstart = msg.payload.lastIndexOf(\"\\n\",end-1);\nl = new Date(parseInt(msg.payload.substring(start+1, end))- 7*3600000);\n // for UTC-7:00 timestamp offset: <(parseInt(..(..)) - 7*3600000)>\nlast = l.toISOString();\n\nmsg.attachments = [{\n filename: first.substring(0,16) + '--to--' + last.substring(0,16) + \".csv\",\n // filename = \"yyyy-mm-ddThh:mm--to--yyyy-mm-ddThh:mm\" trend start date_to_trend end date\n content : msg.payload\n }];\n \nmsg.payload = \"Trend data \" + first.substring(0,10)+\" @ \"+first.substring(11,16)+\" to \"+\n last.substring(0,10)+\" @ \"+last.substring(11,16)+\" for tag \" + msg.sendTag + \" attached\";\nmsg.topic = \"Tag \" + msg.sendTag + \" data\";\nreturn msg;","outputs":1,"noerr":0,"x":730,"y":1220,"wires":[["8515c0b3.249c","24dfed2.1b3a912","c4569ad5.8e3a88"]]},{"id":"8515c0b3.249c","type":"e-mail","z":"e7108e55.3fa88","server":"","port":"465","secure":true,"name":",","dname":"send","x":890,"y":1220,"wires":[]},{"id":"7e800f5b.c7494","type":"groov-read-ds","z":"e7108e55.3fa88","dataStore":"4d99020c.a9acac","tagName":"sendFlag","tableStartIndex":"","tableLength":"","value":"","valueType":"msg.payload","topic":"","topicType":"none","name":"","x":320,"y":1180,"wires":[["f0c56b9b.847008"]]},{"id":"c1b6b855.ad9638","type":"inject","z":"e7108e55.3fa88","name":"","topic":"","payload":"","payloadType":"date","repeat":"1","crontab":"","once":true,"x":310,"y":1140,"wires":[["7e800f5b.c7494"]]},{"id":"f0c56b9b.847008","type":"rbe","z":"e7108e55.3fa88","name":"","func":"rbei","gap":"","start":"","inout":"out","x":330,"y":1220,"wires":[["77d86baf.712d64"]]},{"id":"77d86baf.712d64","type":"switch","z":"e7108e55.3fa88","name":"if true","property":"payload","propertyType":"msg","rules":[{"t":"eq","v":"true","vt":"jsonata"}],"checkall":"true","outputs":1,"x":490,"y":1140,"wires":[["ddc0f0fd.5eb58"]]},{"id":"24dfed2.1b3a912","type":"groov-write-ds","z":"e7108e55.3fa88","dataStore":"4d99020c.a9acac","tagName":"sendFlag","tableStartIndex":"","value":"false","valueType":"value","name":"","x":900,"y":1260,"wires":[[]]},{"id":"c4569ad5.8e3a88","type":"debug","z":"e7108e55.3fa88","name":"","active":true,"console":"false","complete":"true","x":890,"y":1180,"wires":[]},{"id":"ddc0f0fd.5eb58","type":"groov-read-ds","z":"e7108e55.3fa88","dataStore":"4d99020c.a9acac","tagName":"sendTag","tableStartIndex":"","tableLength":"","value":"sendTag","valueType":"msg","topic":"","topicType":"none","name":"","x":500,"y":1180,"wires":[["6f3b4317.043b8c"]]},{"id":"6478babd.ac1a54","type":"catch","z":"e7108e55.3fa88","name":"","scope":["83678c51.86334"],"x":740,"y":1300,"wires":[["24dfed2.1b3a912","f0af4acd.7e6068"]]},{"id":"f0af4acd.7e6068","type":"groov-write-ds","z":"e7108e55.3fa88","dataStore":"4d99020c.a9acac","tagName":"sendTag","tableStartIndex":"","value":"-1","valueType":"value","name":"sendTag = -1","x":910,"y":1300,"wires":[[]]},{"id":"4d99020c.a9acac","type":"groov-data-store","z":"","project":"cb2b7005.0a753","dsName":"WeatherData"},{"id":"cb2b7005.0a753","type":"groov-project","z":"","address":"localhost"}]

Leverage the trend API (for ANY groov Device type) for some Edge computing

There is a problem with this flow, It won’t import. There must be a missing part. Any chances of getting a updated copy? I could really use this in my current project.



Hi Dan! Sorry about that, I’ll make sure to double test code samples after posting in the future. Unfortunately I don’t have the original flow still running to get an exact copy, is there a specific part you’re after? The main logic for the logging URL and curl are in the second flow for email if that is enough of a reference for you otherwise just let me know what you’re looking for and I can have a go at rebuilding it for you



I built most of it out the code provided, but I am looking for the custom function that does the parsing of the downloaded files.

Does that make sense?


We are just trying to nail down exactly what you are looking for.
First flow or second?
Whats the name of the Node you are most interested in?


Hi Ben,

First flow, the node is ‘filename=trend-start’



Here is an import for just that Node to try out:

[{"id":"3605ab3f.3ed154","type":"function","z":"e7108e55.3fa88","name":"filename=“trend-start”–to–“trend-end”","func":"start = msg.payload.indexOf(\"\\n\");\nend = msg.payload.indexOf(\",\", start+1);\nmsg.first_stamp = parseInt(msg.payload.substring(start+1, end));\n// for UTC-7:00 timestamp offset: (parseInt(…(…)) - 7*3600000)\n\nf = new Date(msg.first_stamp);\nend = msg.payload.lastIndexOf(\",\");\nstart = msg.payload.lastIndexOf(\"\\n\",end-1);\nl = new Date(parseInt(msg.payload.substring(start+1, end)));\n// for UTC-7:00 timestamp offset: (parseInt(…(…)) - 7*3600000)\n\nmsg.filename = f.toISOString().substring(0,16) + '–to–' + l.toISOString().substring(0,16) + '.csv';\n// filename = “yyyy-mm-ddThh:mm_to_yyyy-mm-ddThh:mm” trend start date_to_trend end date\nreturn msg;","outputs":1,"noerr":0,"x":1210,"y":1240,"wires":[[]]}]

It uses the first newline character \n and the following comma character , to determine the location of the first timestamp, then similarly uses the last index of those characters to extract the last timestamp from the csv file, then sticks them together in a string on the path msg.filename. The +1 on the character starting points is to make sure it doesn’t try to put the newline character in the file name.
I hope that helps!