Things I Find Interesting
Uncategorized
Publishing Data to InfluxDB from Swift
Mar 29th
I’ve been a very busy man. It was only a few days ago that I wrote about a new InfluxDB library for writing data from Arduino devices to InfluxDB v2 and here I am again, writing about a new library for writing data to InfluxDB. This time, it’s in Swift. Now your native Apple apps can write data directly to InfluxDB v2.0 with ease.
It’s a really simple library to use, and you can download the entire Xcode project for it from my GitHub. You can use it to write single data points to the DB, or to do bulk writes of any size. Here’s a quick tutorial on how to use it.
let influxdb = InfluxData()That gets you an instance of the InfluxData class. Once you have that, you’ll need to set some configuration parameters for it.
influxdb.setConfig(server: “serverName", port: 9999, org: “myOrganization", bucket: “myBucket", token: “myToken")You will, of course, need to set all those values according to your InfluxDB v2.0 server’s settings. You can also set the time precision with
let myPrecision = DataPrecision.ms // for Milliseconds, ‘us' for microseconds, and ’s’ for seconds
influxdb.setPrecision(precision: myPrecision)At this point, you’re ready to start collecting data and sending it to InfluxDB v2.0! For each data point you collect and want to store, you will create a new Influx object to hold the tags and data.
let point: Influx = Influx(measurement: “myMeasurement")
point.addTag(name: “location”, value: “home”)
point.addTag(name: “server”, value: “home-server”)
if !point.addValue(name: “value”, value: 100.01) {
print(“Unknown value type!\n)
}
if !point.addValue(name: “value”, value: 55) {
print(“Unknown value type!\n)
}
if !point.addValue(name: “value”, value: true) {
print(“Unknown value type!\n)
}
if !point.addValue(name: “value”, value: “String Value" {
print(“Unknown value type!\n)
}As you can see, it accepts Integers, floating point values, Booleans and strings. If it cannot determine the data type, it will return the Boolean false so it’s always a good idea to check the return value.
For best performance, we recommend writing data in batches to InfluxDB, so you’ll need to prepare the data to go into a batch. This is easy to do with a call to
influxdb.prepare(point: point)And when it’s time to write the batch, just call
if influxdb.writeBatch() {
print(“Batch written successfully!\n)
}Again, writeBatch() returns a Boolean on success or failure, so it’s a good idea to check those values.
If you want to write each data point as it comes in, just take the data point you created above and call
influxdb.writeSingle(dataPoint: point)You can write data to multiple measurements simultaneously as each data point is initialized with its measurement, and you can add as many tags and fields as you’d like.
This is really the first pass at the InfluxDB v2.0 Swift library as I’ll be adding the ability to query, create buckets, and a lot of other features of the Flux language to the library in the future, but since what most people want to do right away is write data to the database, I thought I’d get this out there.
I hope this is helpful! I know it has been for me! You see, I have lately been just using my Mac laptop to grab data off of my Bluetooth CO2 sensor that I built. In order to do that, I built a small BLE application that connects to the sensor, subscribes to the data ID, and constantly writes the data to InfluxDB. Needless to say, I used this library and have been scraping this data and storing it happily.
I’d love to hear what you plan to do with a Swift Library for 2.0 so be sure to follow me on twitter and let me know what you’re doing!
Warning: Creating default object from empty value in /home/davidgs/public_html/wp-includes/comment-template.php on line 1067
My Winter Vacation (what I did with IoT and ARTIK-5)
Jan 2nd
I don’t know about you, or what you did with your winter vacation (or if you even got one, and if you didn’t, I’m sorry) but one of the fun things I did with mine was to spend a little time with my Samsung ARTIK Dev Kit. If you read the Hardware Extravaganza Post, you’ll know that I got an ARTIK-0 and an ARTIK-5 developer kit not long ago. I’ve been up to my ears in MyNewt though and haven’t had time to do much with them, sadly. That is, until my winter break came along.
I didn’t want to spend the whole time playing in my office and annoy my family, so I decided to just try a quick project using some existing sensor hardware I have lying around. (Note: I have a vast amount of sensor hardware “just lying around”) I decided to try using the eTape Liquid Level Sensor that I’ve already been playing with for the MyNewt project. It’s a fairly simple Analog sensor for reading the water/liquid level in a container. Or, in my case, on my back patio which regularly floods! I also decided to pull out the ARTIK-5 first since it’s extremely easy to get going.
We’re going to use the sensor as a resistive sensor, and the setup is very simple. I’ll be using a breadboard to put this all together for illustrative purposes. First, attach a jumper-wire from 5v on the board to the breadboard.Next, attach a jumper wire from ADC0 on the board to the breadboard. This will be our ADC-in. The sensor should have come with a 560 ohm resistor, so plug that into the board between Vdd and ADC-in holes. Finally, attach a jumper from GND on the board to your breadboard. At this point, your ARTIK 5 should look like this:
And your breadboard should look like this:
Now attach one of the middle 2 leads from the sensor to ground on the breadboad and the other middle lead to the ADC-in on the breadboard. That should complete the sensor hookup and your completed breadboard should look like the above.
I bought a 1000 ML graduated cylinder in which to put the eTape sensor for testing this project, and here’s what the final hookup of the sensor itself looks like:
Now all I have to do is fill it with water and … oh, wait, I probably have to write some code, huh? Actually, it turns out I have to do surprisingly little of that! I decided to give the Node-Red a spin since I’ve been writing a lot of Node.js code this year anyway. I got my ARTIK-5 up and running using the Resin.io site which was really fast and easy to use. Once that was done, and I had a fully operational ARTIK 5 (Note: don’t use the slim profile, make sure you use the latest profile in your Docker setup. You’ll need it for installing Node-Red), I simply installed Node-Red using
# sudo npm install -g node-red
Once that completed, I installed the ARTIK library for Node-Red
# /root/.node-red # npm install node-red-contrib-artik
Then, just to make things even easier, I installed the FRED module:
# npm install node-red-contrib-fred
You’ll see why FRED was a good idea in a minute. Once that was all done on the ARTIK 5 I simply started node-red:
# node-red
And then connected my browser to the ARTIK-5 Node-Red server and built an app. I dragged in an ARTIK ADC and configured it:
a Function
and a JSON module, and then hooked it all up to a FRED-input and a FRED-output:
Oh, and then clicked the ‘Deploy’ button. Told you it was simple.
I then went over to my FRED service account at sensitec and logged in. I created a private ADC endpoint:
And then added a send ADC event, triggered by a timestamp:
And a receive event that takes the returned data and inserts it into a chart:
Once I started the whole thing, I had a nifty chart showing the water level in my graduated cylinder:
And I wrote essentially zero code.
Next I’ll try installing a MongoDB backend on the ARTIK-5 and sending all the data to that, and then serving that data out to a javascript front-end to chart it all. That will require writing some code, so look for that in the near future!
Also I’ll work on having the actual sensor connected to the ARTIK-0 and sending the data from that to the ARTIK-5 MongoDB instance for collection and analysis. I’m really looking forward to digging in to the ARTIK-0 a bit since that’s more hands-on with C code — something I’ve been neck-deep in lately with MyNewt anyway.
New Blog!
Oct 23rd
As the year draws to a close, I had this wild idea to revive my personal/professional blog. I have no idea why, but it seemed like a good idea at the time. So I rebuilt the template I had made years ago to go with my website and here we are!
Yes, I do occasionally blog for my job as a Technology Evangelist at Riverbed, but there are lots of other topics I’d like to blog about that don’t seem to be right for that venue, so I’ll put them here. I’m still interested in the Internet of Things, which I used to blog about almost incessantly when I was at Sun Labs (a moment of silence, please), traveling — which I do a lot of these days — and other topics of interest to me. For a list of things I’m interested in, feel free to see this list.
In reality, it could be anything. Being polite company, it won’t be politics or religion, but you can get that anywhere on the internet these days. The last thing the world needs is another place for that drivel. I have no idea how regularly I’ll post, but if there’s something you want to see me cover, feel free to contact me. If it’s urgent, contact me here.
Recent Blog Comments