Esparto v2.0 - sneak preview: Outside

"Esparto" is a type of coarse grass. That's neither here nor there really but it's a nice name for this Arduino ESP8266 library. Originally it stood for ESP All-purpose Run-Time Object, but it could just as well be "ESP All Ready To Operate" because that's what it is.

It is a C++ class object which does almost everything you need to do to turn your Wemos D1, NodeMCU, ESP-01S or Sonoff device from a pretty brick into an MQTT-controlled IOT device. Some folk would call it "firmware" and indeed you can upload a binary if you choose, but the real power comes when you extend it yourself with your own code.

As it stands, it will connect to your WiFi and MQTT controller and automatically reconnect after they fail - without rebooting. It will give you a visual (near*) real-time view of all the GPIO pins, with the correct labels on each depending on the device its deployed on. It will accept OTA updates and runs a web server that allows simple reconfiguration.

Using MQTT you can switch it on of off, reboot it (though you shouldn't need to) or factory-reset it. You can even dynamically change its deviceID and SSID+Password. You can read or write any IO pin and/or reconfigure them. What that last one means exactly will become clear later. Through all of this the basic on/off functionality will continue to work, even if your MQTT controller or complete local network are down.You don't need someone else's cloud and a flaky app on your iPhone. Anything that runs a web browser inside your network can control it. So even without your own additional code, it already does a lot.

Once you start adding your own code, the world of Home Automation and IOT is your oyster. In the example that follows, the device is running mu own Chez Toi ioT "truc" firmware, which provides a common interface for a number of sensors (PIR, light, sound, temperature) adds RF433MHz "dumb" switch control and stores the location and function of the device so that the NODE-RED controller can present a smooth UI for the overall management of the whole system.

Basic Esparto:

From the top: Device name, SSID+password change. No reboot, it just reconnects to the new settings. You will need to browse to another "devicename.local" page of course if you change the name or another IP page if the new SSID has a different range.

We'll come back to the "settings" cog icon in a moment, but the yellow circular arrow reboots the device and the factory icon resets it to as close to its original state as possible.

The next panel shows the current state of all the GPIOs, each labelled appropriately for the type of hardware its running on. The top row is the "raw" state of the pin, i.e. its instantaneous value, irrespective of what is connected to it. If it is configured as an output (e.g. the LED or RELAY in a Sonoff device) clicking the top row pin will toggle the state and switch the GPIO on or off. The bottom row will make more sense in the next article when we look "inside" at the code, but for now, just know that these are what Esparto calls the "cooked" state.

Esparto is based on the SmartPins library, which is itself based on the H4 timer / scheduler library. (See the side panel links to these for full documentation - all the functionality will be available in Esparto V2.0, plus a lot more of course. Or see http://github.com/philbowles/smartpins and http://github.com/philbowles/h4) . I'll also cover in the next post why those are both "good things" and will save you months of pain. SmartPins defines number of useful input types such as "debounced", "latching", "encoder" and several more. It does all the work to manage the pin, keep those lights updated and call your code back when the pin changes. So a "raw" button which is bouncy will flicker on and off as it bounces, but once SmartPins has done all the hard work and debounced the pin it puts the corresponding bottom line "cooked" pin on and calls your code. 

The next panel shows some vaguely-useful static information and the final panel shows dynamic information - including MQTT connection status - which is useful when you start adding your own code.

Back to the "setting" gear wheel. Out-of-the-box it will give you a "404" error. That is because it links to a "config" page that you add for the extra functionality that your code provides. Esparto has been specifically designed to make this easy for you, and we'll see just how much so in the next article. For the moment let's look at what Chez Toi ioT "truc" firmware adds:

Chez Toi needs to know where each device lives, to "wire together" important sequences, e.g. "Going to bed" turns on the bedroom light and the landing light and maybe later, the heater if the temperature is below 14degrees. Much of that added "intelligence" is in the raspberry Pi NODE-RED controller in order to keep the code "footprint" in each device as small as possible.

By knowing the location and function, I can add MQTT commands to turn on all devices in a zone, or all floor lamps in the whole system. "Restart" determines if the device is on , off or whatever it was before in the (rare) case of reboot or power outage. A safety nightlight for example would be (as before) but generally "off" is safest.

The numbers (all in milliseconds) are the configuration values for the sensors. PIR(t) is the PIR timeout and PIR(h) is its "hysteresis", meaning the "dead time" between two movement events to prevent it flicking on and off too rapidly. Sound is the timeout value for the re-triggering sound sensor, and light and temp are the frequency to poll those two sensors, since they change slowly.

This particular "truc" is also an RF master controller. When it switches on, those three 433MHz switches will also go on. Or off, of course. Clicking on any will toggle its current state to allow  degree of "manual" control. No more searching for the handset - any browser-capable device will do, tablet, phone, PC etc.