How and what am I using Node-RED for...
I'm using Node-RED on my Raspberry Pi 3B+ and made a simple way to use the GPIO ports to control my home made hardware interface using 2 identical ULN2003A chips, the chips output channels connect the 12 volt RGB LED strip channels to ground to light up the LEDs.
The ULN2003A chip is a darlington array which is very helpful because it allows the 3.3 volt GPIO to be connected to the input channels without a current limiting resistor because the ULN2003A device has a series base resistor to each Darlington pair, thus allowing operation directly with TTL or CMOS operating at supply voltages of 5 V or 3.3 V.
The ULN2003A device offers solutions to a great many interface needs, including solenoids, relays, lamps, small motors, and LEDs. Applications requiring sink currents beyond the capability of a single output may be accommodated by paralleling the outputs.
Why I'm using Node-RED
Well, after searching online for ages I didn't find anything useful and interesting for me to learn except for some Python code to control my RGB LED strips until I found Node-RED.
Node-RED is just awesome because I'm virtually unlimited when it comes to home automation and helping me to create a way to control my 'dumb analog' RGB LED strips via the Raspberry Pi GPIOs with my mobile phone.
At first I found a node called "Ledborg" which is great because it recognizes a range of inputs ie. you can set the color with a string as in red, blue, green, yellow, amber, purple etc. but it has some limitations in that it uses only 3 GPIO pins which can't be changed and it's limited to just those 3 default pins and it was pretty complicated to get my simple LED strips working and giving me the right color, this is especially when I want to use Node-RED Dashboard color picker that to my knowledge should work with ledborg since it should be able to recognize the hex code output from the color picker but I just couldn't get it to work at all and because I'm not familiar with JavaScript to make a function node for the conversion of the hex code output to the 3 number character (255,255,255 for white light) that the ledborg node can understand as a workaround...
Well, that didn't happen so I ditched that plan using ledborg because there's just no info at all on their website and they didn't anticipate that their node would be used the way I did, they want you to buy their ledborg hat for Raspberry Pi and that's not what I want so I made a new Flow and I now have the most simple way using 3 sliders on the Node-RED Dashboard to control the RGB channels and set it to anything I want which is exactly what I wanted to do in the first place.
Plans for the future
I think that other people would want to use Node-RED on their Raspberry Pi with those ULN2003A chips as well so I'm planning to make a new Node-RED node especially for the ULN2003A chips, I'm already working on it for myself so that I have a way to install the node if for whatever reason I have to start over new with a clean install and that way I will naturally progress into making it publicly available.
I'm also working on integrating Google Assistant and Hass.io for Home Automation which is a challenge but very promising and if I can figure all this out I may be able to make it easy for you to use the ULN2003A chips with Home Automation and Google Assistant via my Node-RED node if there's is any interest for it.
I need your thoughts, recommendations to help me make a decision.
Please let me know what you think and leave me a comment, thanks.
Best regards,
Ricardo Penders.
