I'm still on vacation and still on the mend from surgery. I'm continuing to play around with IoT devices on my staycation. Last week I looked at these devices:
Connecting my Particle Photon Internet of Things device to the Azure IoT Hub
Playing with an Onion Omega IoT device to show live Blood Sugar on an OLED screen
Today I'm messing with the Tessel 2. You can buy it from SparkFun for the next few weeks for US$40. The Tessel is pretty cool as a tiny device because it includes WiFi on the board as well as two USB ports AND on-board Ethernet. It includes a two custom "module" ports where you can pop in 10-pin modules like Accelerometers, Climate sensors, IR and more. There's also community-created Tessel modules for things like Color Sensing and Motion.
Tessel is programmable in JavaScript and runs Node. Here's the tech specs:
580MHz Mediatek MT7620n
Linux built on OpenWRT
802.11bgn WiFi
WEP, WPA, WPA2-PSK, WPA2-Enterprise
64MB DDR2 RAM
32MB Flash
16 pins GPIO, 7 of which support analog in
2 USB 2.0 ports with per-port power switching
Tessel isn't a company, it's a open source project! They are on Twitter at @tesselproject and on GitHub here https://github.com/tessel.
NOTE: Some users - including me - have had issues with some Windows machines not recognizing the Tessel 2 over USB. I spent some time exploring this thread on their support site and had to update its firmware but I haven't had issues since.
Once you've plugged your Tessel in, you talk to it with their node based "t2" command line:
It's built on OpenWRT and you can even SSH into it if you want. I haven't needed to though as I just want to write JavaScript and push projects to it. It's nice to know that you CAN get to the low-level stuff I you need to, though.
For example, here's a basic "blink an LED" bit of code:
The programming model is very familiar, and they've abstracted away the complexities of most of the hardware. Here's a GPS example:
Of course, since it's using node and it has great Wifi or wired, the Tessel can also be a web server! Here we return the image from a USB camera.
I'll make a Hello World webserver:
Then push the code to the Tessel like this:
Where is my Tessel on my network?
Now I'll hit the webserver and there it is!
There's a lot of cool community work happening around Tessel. You can get involved with the Tessel community if you're interested:
Join us on Slack — Collaboration and real time discussions (Recommended! - ask your questions here).
Tessel Forums — General discussion and support by the Tessel community.
tessel.hackster.io — Community-submitted projects made with Tessel.
tessel.io/community — Join a Tessel meetup near you! Meetups happen around the world and are the easiest way to play with hardware in person.
#tessel on Freenode — IRC channel for development questions and live help.
Stack Overflow — Technical questions about using Tessel
Sponsor: Big thanks to Telerik! They recently published a comprehensive whitepaper on The State of C#, discussing the history of C#, what’s new in C# 7 and whether C# is the top tech to know. Check it out!
© 2016 Scott Hanselman. All rights reserved.