After a busy month I decided to spend some energy on doing hardware instead of software and the result was the ESPurna board I posted about just yesterday. The goal was to have a device based on the ESP8266 I could fit into my house wall gangs, with an SPDT relay to work with multi-way switches and power monitoring using the same IC the Sonoff POW uses: the HLW8012.
As a side project today I’ve been searching on the box of the TODO projects and I have rescued a KEMO STG15 [Ebay] plug housing with socket. These sockets are somewhat expensive and really bulky but the good thing is that there is quite some room to fit some electronics inside, but not a Sonoff board, too big.
Some weeks ago a tweet by Manolis Nikiforakis (@niki511) with the #ESP8266 hashtag drew my attention. Manolis had just received a “smart lamp” branded by Ai-Thinker, the AiLight. Yes, the same Ai-Thinker that has sold millions of ESP8266 based modules. Chances were it had an ESP8266 microcontroller inside. Too good not to buy one and take a look at the inside.
I actually bought two because you never know. And they arrived last Thursday. It took me less that 1 minute to open one of the boxes, pop out the cap and take a look at the inside just to see what I already knew. Time to play 🙂
My MQTT network at home moves up and down a lot of messages: sensor values, triggers, notifications, device statuses,… I use Node-RED to forward the important ones to PushOver and some others to a Blynk application. But I also happen to have an LED display at home and that means FUN.
LED displays are cool. Your team’s score, your number in the IRS queue, the estimated arrival time for your next commute,… Now that TVs are replacing LED displays (like the later did with the electromechanical ones) they have acquire an almost vintage-status.
This LED display I own even has a name: The Rentalito. The Rentalito is an old friend, one of those projects you revisit because LED displays are cool… Originally it was an Arduino Uno with an Ethernet Shield in a fancy cardboard case. Then it went WiFi using a WiFly module. And then a SparkCore replaced the Arduino. Now… well, ESP8266 is driving my life.
Let me introduce you the latest iteration of the Rentalito, the MQTT LED matrix display.
Some 3 years ago I started building my own wireless sensor network at home. The technology I used at the moment has proven to be the right choice, mostly because it is flexible and modular.
MQTT is the keystone of the network. The publisher-subscriber pattern gives the flexibility to work on small, replaceable, simple components that can be attached or detached from the network at any moment. Over this time is has gone through some changes, like switching from a series of python daemons to Node-RED to manage persistence, notifications and reporting to several “cloud” services.
But MQTT talks TCP, which means you need some kind of translators for other “languages”. The picture below is from one of my firsts posts about my Home Monitoring System, and it shows some components I had working at the time.
All those gears in the image are those translators, sometimes called drivers, sometimes bridges, sometimes gateways. Most of them have been replaced by Node-RED nodes. But not all of them. This is the story of one of those gateways.
Have you ever forgotten your wet clothing inside the washer for a whole day? I have. Even for two days. They smell. You have to wash them again and you know you might end up forgetting about them again!
Actually that is happening to me since me moved to an old house in a town north of Barcelona. Instead of having the washer in the kitchen, like we used to, now we have it in the cellar, in a place I don’t normally pass by to notice the laundry is done.
So I started thinking about monitoring the washer to get notifications when the laundry is done. And since I was at the same time playing with ITead’s Sonoffs, which has an AC/DC transformer and a powerful controller with wifi, it looked like a nice project to put together.