Tuesday, March 10, 2015

node-red is best for... everything

Like I said in a previous post, node-red is becoming for me more and more the first choice for all kinds of projects I'm doing. I can definitely write code for all these little things but every time I start a project I ask myself first if it can be done in node-red.

Case in point: yesterday I remembered the DigiSparks I got a while back from kickstarter and decided to play with them. As you may know, a Digispark is a tiny Arduino-like device, not 100% compatible (because it uses the Attiny85 controller unlike Arduino's ATmega168/328) but plenty powerful; one of mine has an RGB shield; when I first got it from the kickstarter project I downloaded the example code from github and after quite a lot of fiddling I got it to work, both on my Linux Mint laptop and my Raspberry Pi. But that was a long time ago so now that I wanted to play with it a bit more I decided to see if I can make it work with node-red. First thought was that I could probably use the exec node and issue the same DigiRGB.py command I did last time.

But a quick search pointed me to the digirgb node. I quickly installed it but got make errors related to node-hid. After quite a lot of time spent on the web trying to figure out what may be wrong with my environment and after installing quite a few extra libraries and packages I found mentioned here and there (like libssl-dev and build-essential), I did what I should've done from the start: read the error message more carefully; this is how I noticed it said libusb.h missing. Tried:

$ sudo apt-get install libusb-1.0-0

but it was already up to date. Next I tried:

$ sudo apt-get install libusb-1.0-0-dev

and to my surprise this time npm install finished without errors. I connected my Digispark with the RGB led and checked it was visible: $ lsusb -> shows Bus 001 Device 005: ID 16c0:05df VOTI

Restarted node-red and the digiRGB node was right there. A quick test with an inject node sending a "100,100,100" string turned on the LED from the first try. I know by now I should not be amazed any more that node-red is so great but I still am, every time - it is simply awesome!

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