Moving from the ESP8266 world I’ve been diving lately I still love the simplicity of battery powered Moteino nodes. You might know I’m migrating my XBee-based sensor network at home to an RFM69 one. So long I have changed my door monitor and my weather station. They are sensing and reporting to my RFM69GW, an ESP8266 bridge board using a custom firmware.
Time to go for the power monitor. A long time ago (actually 2 years but it really feels like a century ago) I was living in a big city and we had one of those fancy “smart meters” with a LED pulsing 4000 times every kWh. Back then I used an Arduino micro to count the LED pulses and report the power every minute through an XBee link.
But now I live in a small town and my house electrical system is somewhat “old”. My power meter comes from somewhen in the 60s (maybe not so old). So a non-invasive current sensor makes a bit more sense (ehem).
November was a busy month and the Sonoff Dual that IteadStudio kindly sent me to review was bored in a box waiting for some free time. But it was just fair that another board that has been waiting in the boards-to-review box for longer had it’s chance to have some fresh air too. So here we have the Itead Studio Sonoff Dual and the Electrodragon ESP Relay Board face to face.
A few week ago I had a really good time testing 4DSystems 4Duino-24 board. One of the things I noticed is that the Serial Command Set interface is really flexible. You can easily drive the display from an 8-bit microcontroller. But you can also use more powerful controllers like an ESP8266 or an ARM machine like a Raspberry Pi or even my laptop.
4DSystems provide libraries for all those platforms and others. Most of those libraries share a common language: C (they have also developed libraries in Basic for PicAxe and Pascal). But even thou I spend a lot of time write C code, when I’m on my laptop a prefer higher level languages like Node.js or Python. So why not using Python to control these displays?
Actually, Python being written in C itself has a great support to wrap C libraries so you can use them from the language. Using Python to develop has several advantages:
Powerful language with complex but easy-to-use data structures
Rapid development since it’s an interpreted language
Mostly platform independent (you still need to compile the C libraries for your platform, but the wrapper and example should work without modifications)
A few weeks ago I wrote about my new door monitor. It was the first step towards migrating my XBee based wireless sensors network to RFM69 radios using Moteino platform by LowPowerLab. I was truly impressed by the low power consumption so I committed myself to keep on working with them.
Coincidentally Felix Russo, the guy behind LowPowerLab, released the new version of it’s Weather Shield for Moteino. So it was time to update (or completely revamp) my trusty Arduino FIO based weather station… and last week I received a parcel from LowPowerLab with a pair of shields to play with: the new WeatherShield R2 and the PowerShield R3. They are both compatible with the Moteino (off course).
From left to right: PowerShield R3, Moteino and the new WeatherShield R2
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.