A few months ago I wrote about the Sonoff SC sensor hub by Itead Studio. It’s a device with a Sharp GP2Y1010AU0F [Aliexpress] dust sensor, a DHT11 humidity and temperature sensor, an LDR as light sensor and a mic. The sensors are driven by an ATMega328P microcontroller but there is also an ESP8266 on board for WiFi communication, a pretty standard set up when you have several sensors and the ESP8266 GPIOs are just not enough.
On the first post I already did a small mod to replace the DHT11 humidity and temperature sensor with a more accurate and pin compatible DHT22. Since then, several readers have contributed with code and ideas. My progress implementing and testing them is slow, so I though about writing a first post about some modifications I (and others) have done to the device.
So this is a work in progress post. At the moment, all the code for these modifications is in the dev branch of the repository.
This custom Sonoff SC firmware is released as free open software and can be checked out at my SonoffSC repository on Github.
Last December Itead Studio updated their Home Automation product line with a new and different product. The main difference is that it doesn’t have a relay and it’s mainly sensors and no actuator (if we don’t define a notifying LED as an actuator). The Sonoff SC is a sensor station that packs a DHT11 temperature and humidity sensor, a GM55 LDR, an electret microphone with an amplifier circuit and a Sharp GP2Y1010AU0F [Aliexpress] dust sensor in a fancy case that looks like it was originally meant for a speaker.
The device is packs an ESP8266 as expected and is compatible with the eWeLink app. But, such a collection of sensors, with 3 of them having analog interfaces, cannot be run from the single-ADC ESP8266 so Itead has thrown in a good old ATMega328P to drive the sensors and report the Espressif with the data.
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.
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.