Recent Updates (March 1st, 2019)

Otto Winter has been continuing his updates to esphome with improvements to the set-up wizard and the addition of min/max settings for rotary encoders (esphome enables you to add an ESP8266 or ESP32 to Home Assistant without writing any code).

Theo Arends has been working on reducing stack space usage in Sonoff-TASMOTA to fix some intermittent crashes.  If you’re having issues, please upgrade to version 6.4.1.18 or greater (see this post for more details).

Phil Bowles has been updating the API documentation and examples for his esparto rapid development framework for the ESP8266 (available as an Arduino IDE library; write concise, working code with no setup() or loop() functions).

Xose Pérez has made lots of changes to his espurna replacement firmware for ESP8266 devices over the past few weeks, with support for more than twenty new products added and the incorporation of many fixes (both from Xose himself and submitted by an ever-growing community of users).

Rich Heslip has published an ESP32 project, “Motivation Radio BLEMIDI”, to add WiFi and Bluetooth functionality to Eurorack based modular synthesizers.  The hardware for this module is also open source and available from a separate repository, courtesy of Jim Matheson.

 

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TASMOTA exceptions and watchdog resets

Just a quick note on recent TASMOTA changes.  Theo has been pushing out some updates over the past couple of days to fix an intermittent stack overflow problem which has cropped up with some combinations of hardware and TASMOTA firmware.  The issue seems to manifest itself with TASMOTA versions 6.4.1.16 and 6.4.1.17 and some devices which do load current monitoring (eg:- the NX-SP201 series, double-outlet smart switches).  Initial indications are that executing a “status 0” command at exactly the same time as the current monitor is updating can run the device out of stack space.

Bottom line… update to release of 6.4.1.18 (or greater) if you’re seeing these symptoms.

Recent Updates (Feb 14th 2019)

I’ve added Mike Rankin’s Twitter feed to the ESP32 links section (RH column).  Mike has several ESP8266 and ESP32 projects in his Github repository and usually has some interesting commentary on his Twitter feed (ongoing status, problems, fixes, etc).  His latest project, a rechargeable-coin-cell based ESP32 mini board, is definitely worth a look, as are his previous ESP8266 creations.

Theo and his merry band of helpers have been hard at work pushing out more updates to Sonoff-TASMOTA.  Along with some code refactoring at the end of January to change “boolean” types to “bool” and “byte” to “uint8_t”, some other interesting updates have just slipped out in the last couple of recent releases:-

  • Templates.  This is a great new feature which allows people to  add new device GPIO definitions via JSON templatesA repository for user-submitted templates has already been created.
  • Support for multiple ADS1115 devices on the i2c bus.  If you’ve been limited by the single AtoD pin on the ESP8266, you can now add up to four, four-channel ADS1115 devices (on unique addresses) to the i2c bus and have them automatically recognized.
  • Numeric operators “==”,  “!=” ,  “>=”  and  “<=”  added to rules (the previously existing  “=”  string comparator frequently produced unexpected results when used in a numeric context).
  • HASS discovery and status for sensors.

Martin Ger has just updated his esp_wifi_repeater package to handle MQTT QOS (in version 2.2.5).

Adding Alexa control.  Phil Bowles has released a tiny Wemo emulator library, “weenymo.  It’s about 60 lines of code and adds Alexa on/off functionality to your ESP8266 projects (and don’t forget to check out his “esparto” rapid development library while you’re visiting his GitHub repository).

Otto Winter has integrated the esphomeyaml and esphomelib projects under the umbrella name of “esphome.  If you haven’t come across either (any) of these before, the basic idea is that a user can write a short configuration file and have code automatically generated for an ESP8266 or ESP32.  With esphome, you can have an application up and running on your ESP in a few minutes without writing a single line of code yourself.

Recent Updates (20th Oct 2018)

esp-go  –  Pete Scargill’s re-badged “Hackitt & Bodgitt” code for a universal i2c Nano peripheral extender for the ESP8266.

Pete has mainly been updating the documentation for his code over the past couple of weeks.  In the latest release, the name has changed to “esp-go.doc” to reflect the re-branding.

 

badgy  –  SQFMI’s “Swiss Army” e-Ink badge,based on the ESP-12F.

SQFMI has updated the code to work with the latest version (3.0) of the GxEPD library.

 

mobile-rr  –  idolpx’s ESP8266 Mobile Rick-Roll Captive Portal.

idolpx has added some images to the documentation to help novice ESP8266 users get a better grasp of what they’re doing, as well as updating the code to add DNS overrides and improve the WiFi scan filtering.

 

Sonoff-Tasmota  –  Theo Arends’ all-purpose replacement for Sonoff firmware.

Theo has been steadily updating and improving the 6.2.1 version of his firmware with (in no particular order):-

  • A change to a non-blocking MQTT library as the default.
  • Add support for the DS3231 RTC.
  • Add TasmotaModbus library.
  • Add support for the HX711 load cell.
  • Add support for Pzem energy monitors.

…as well as various fixes.

 

IRremoteESP8266  –  A library to enable IR send and receive on the ESP8266.

Mark has updated the package to support Disney’s “Made With Magic” protocol.

 

 

 

TASMOTA Update

Over the past weekend, Theo pushed out another fairly big update to TASMOTA with some interesting new additions.

  • Language file support for:-
    • Portuguese
    • Czech
    • Bulgarian
    • Russian
    • Hungarian
    • Greek
  • Addition of  “rules”, to enable local, logical control of devices based on various inputs (so, for instance, a self-contained thermostat application can now be implemented internally on the Sonoff module, without requiring support via MQTT or other external methods).
  • Addition of KNX UDP protocol support to enable integration of Sonoffs into building automation projects.
  • The re-addition of variable support for MQTT client/topic values, using the ESP chip-ID.
  • Addition of a new, optional OTA upgrade method to allow for a PlatformIO-type “push” of large binaries (up to ~700kB) without requiring the use of a local web server.
  • Addition of support for hardware and software serial bridging (text only).
  • Addition of support for the Zengge ZJ-WF017-A PWM LED strip controller (ESP12S based).
  • Addition of support for the SGP30 air quality sensor.
  • Addition of sunrise/sunset option for scheduling (by geographical location).

As well as all of these new additions, there are a whole host of fixes and updates to existing features.  Definitely worth checking this one out!

 

Using oddball ESP boards with TASMOTA – Part III (MQTT)

Continuing with our series of articles on utilizing Theo Arends’ TASMOTA firmware on non-Sonoff boards and devices, in this article we’ll look at using MQTT to interact with the target.

Feel free to skip over the next four paragraphs (between the horizontal delimiters) if you’re already familiar with the way in which MQTT works.


Just in case you’re not familiar with MQTT, I’d like to emphasize here that it is not an interactive mode of communicating with your device in the way that using a serial adapter, console or telnet/ssh connection is.  In concept it is more like using radios for verbal communication; you have both a transmitter and a receiver, but they are two separate pieces of equipment.  If you transmitted a message, you wouldn’t hear any reply if your receiver wasn’t turned on and tuned to the appropriate frequency.  Likewise, without a transmitter (again, tuned to the correct frequency) you would simply be a passive listener to whatever was received.  MQTT is similar; you need to know the “frequency” (the topic) which you want to communicate on and you need a transmitter (a publisher), as well as a receiver (a subscriber).

To complicate matters a little further, you are running your radio equipment in a deep valley, surrounded by mountains.  In order to use your radio you need to use a repeater station, situated on a nearby summit.  The operators of the repeater are very generous and will freely rebroadcast anything they receive on to you , just as long as you tell them which frequencies you want to receive.  All of your radio traffic, both outgoing and incoming, needs to go via this repeater.  In MQTT terms, the repeater is a “broker” which will listen for messages and rebroadcast them.  You can receive and transmit messages at will, as long as you specify a topic.

The most common MQTT broker for home use is Mosquitto, which comes with a couple of command-line utilities, “mosquitto_sub”, a subscriber (or receiver) and “mosquitto_pub”, a publisher (or transmitter).  You would run Mosquitto on one of the machines on your home LAN (say, perhaps a Raspberry-Pi or a dedicated NAS or back-up system which is running 24/7).  The Mosquitto daemon provides a fully functional MQTT “broker”, but you can also install the mosquitto-clients package on your desktop or laptop to make the mosquitto_sub/pub utilities available, without the overhead of the full daemon.

Anyway, enough of the radio analogy.  The important things to remember with MQTT are that:-

  • You won’t automatically get any response from a “pub” message sent to your ESP, unless you are also listening to the correct topic with a “sub”.
  • MQTT is a distributed protocol, in the sense that your subscribers will usually be on a different physical machine than the publishers and probably neither of them will be on the same machine as the broker.

On the ESP8266 side, there are a few libraries available which give moderately pain-free access to MQTT from your program.  Currently I’ve been favouring Nick O’Leary’s PubSubClient library and, luckily, Theo includes it by default in TASMOTA, so you don’t need to do anything extra; MQTT capability is built-in.

So, lets get started with MQTT.  As suggested in the previous article, I’d recommend opening up the wiki page describing TASMOTA commands and using it as a handy reference while you’re playing with this.

Example of "screen" with top and bottom window splitHowever, before we jump into the commands themselves, I’d recommend that you bring up two separate windows on your display to allow you input “transmissions” in one window while simultaneously being able to see received messages in the other (if you’re using a full-screen terminal window on some modern version of Un*x, you can also use the “screen” utility to split your single window into top and bottom halves, using “CONTROL-A S”, followed by “CONTROL-A TAB” to swap between the new, top and bottom windows and then “CONTROL-A c” to create a new shell in the bottom window [¹]).

In your top window, start a “receiver” process to monitor the output on TASMOTA’s “stat” (status) topic.  This is where you’ll see the messages which TASMOTA is sending back to the MQTT broker.  Your command will look something like this:-

mosquitto_sub -h mybroker.mylan.com -t “stat/sonoff/#”

…where “mybroker.mylan.com” is the machine where the main mosquitto daemon is running (your “broker”) and “sonoff” is the “friendly name” you’ve given your module in TASMOTA.  The “#” character at the end of the topic string (“stat/sonoff/#”) is the MQTT wildcard character and, in this case, tells the mosquitto_sub command that we want to see all messages that match the “stat/sonoff/” string, whether they be the result of command execution or specific subsystem (ie:- memory) informational messages.

If your broker process is running on a separate machine, the commands which you type in can get quite long, so I’d also recommend building up a couple of aliases for the mosquitto_sub and mosquitto_pub commands (I covered this in an earlier MQTT how-to article).

[ NOTE:- From this point onwards I will use the aliases “mqp” for mosquitto_pub and “mqs” for mosquitto_sub to try and limit the example commands to a single line. ]

As when using the console commands earlier, we’ll start with some simple commands to manipulate the green LED.   Here’s where a simple rule will help out — IF YOU’RE SENDING A REQUEST OF ANY SORT, YOU NEED TO USE THE “cmnd/*” TOPIC.  In this particular instance, it may seem intuitive to use the “stat/*” topic, because we want to see some status, but you need to remember that we’re not using an interactive terminal session; we’re using the transmit and receive functionality of MQTT, so we must send any request as a command.  This takes a little bit of getting used to, but will become second nature very quickly.  So in this case, the command you send to your module will look something like this:-

mqp -t cmnd/sonoff/LedPower -n

The “-n” tells mosquitto_pub that there is no message part to this particular command.

Once sent, you won’t see any  other output in your “transmit” window (unless you’ve made a typo), but over in the window where you left the mosquitto_sub command running in background, you should see the response:-

{"LedPower":"OFF"}

…or possibly “ON”, of course.

Controlling the LED is more intuitive than just getting the status:-

mqp -t cmnd/sonoff/LedPower -m "on"

We’re using the same basic command, with exactly the same topic (“cmnd/sonoff/LedPower”), but a different message (the ‘-m “on”‘ part) and, as you’d expect, this turns on the LED on your remote module and, in addition, TASMOTA automatically sends a status update message, so your mosquitto_sub (receiver) window will display:-

{"LedPower":"ON"}

Then use:-

mqp -t cmnd/sonoff/LedPower -m "off"

…to turn it back off again (hopefully your ESP8266 module is somewhere within sight, so that you can visually check that these commands are indeed working).

The next step is to simply replace “LedPower” with just “Power” and verify that the relay on your ESP8266 is also responding to on/off commands.  The output in the mosquitto_sub window will change to:-

{"POWER":"ON"}  and  {"POWER":"OFF"}

Our next command will return the status (the current pwm count between 0 and 1023) for each of our previously assigned PWM drive pins (the red and blue LED segments of the RGB LED on the Yellow Dev board).

mqp -t cmnd/sonoff/pwm -n

Note that we’re again using the “-n” to tell mosquitto_pub that there’s no message part to this topic.  The output on the mosquitto_sub screen will probably look something like this:-

{"PWM":{"PWM1":0,"PWM2":0}}

The output is just a little more complex, as there are now two separate GPIOs in the overall PWM status report.  I’m sure that by now you don’t need me to tell you that using those PWM1 and PWM2 ids, you can now control your red and blue LEDs in the same way as we did from the console, but using the message part of the MQTT command to vary the PWM drive output:-

mqp -t cmnd/sonoff/pwm1 -m "750"

…returns:-   {"PWM":{"PWM1":750,"PWM2":0}}

mqp -t cmnd/sonoff/pwm2 -m "350"

…returns:-   {"PWM":{"PWM1":750,"PWM2":350}}

Note that the response status from the command still includes all of the defined PWM pins, even though our command lines only change one GPIO pin at a time.

Following along from the examples we went through previously in the “Console” tutorial, we’ll now request TASMOTA to send us the status (including the data) from our on-board temperature sensors.  If you remember, we needed to send the command “status 10” from the console, which translates into another command string for mosquitto_pub.

mqp -t cmnd/sonoff/status -m "10"

…and the response this time (in the mosquitto_sub window) is much longer (this would all be on one line on your screen):-

{"StatusSNS":{"Time":"2018-02-14T09:46:58","DS18B20-1":{"Id":"011590E534FF","Temperature":1.50},"DS18B20-2":{"Id":"031590A618FF","Temperature":35.25},"TempUnit":"C"}}

Anyone who has played around with IOT data in the past few years will recognize this (and the previous examples) as JSON formatted data.   Here we can see that the overall encapsulation is “StatusSNS” and within that we have several different types of data returned.  The first is a timestamp which needs no explanation, but the following two blobs of data:-

"DS18B20-1":{"Id":"011590E534FF","Temperature":1.50},

and

"DS18B20-2":{"Id":"031590A618FF","Temperature":35.25},

…are more interesting.  The strings “DS18B20-1” and “DS18B20-2” are arbitrary identifiers used by TASMOTA to identify individual one-wire temperature sensors.  The “Id” numbers are the actual serial numbers of the DS18B20s themselves (each sensor has a unique serial number burned into its ROM when manufactured).  “Temperature” is again obvious, but just in case of ambiguity, the last part of the StatusSNS data (above) is a specifier for the temperature unit being used (in this case, Celsius).

We can change the temperture reporting units to Fahrenheit using the “SetOption8 1” command:-

mqp -t cmnd/sonoff/setoption8 -m "1"

…and the next time we get a temperature status report, the figures are quite different:-

{"SetOption8":"ON"}

{"StatusSNS":{"Time":"2018-02-14T09:47:38","DS18B20-1":{"Id":"011590E534FF","Temperature":35.04},"DS18B20-2":{"Id":"031590A618FF","Temperature":83.97},"TempUnit":"F"}}

Okay, we’ve covered the same commands as we did in the “Console” article and reached the point where TASMOTA and MQTT are delivering a bunch of useful data back to us from our project board.  In the next part I’ll look at creating a shell script to automatically generate and handle that (JSON) data, so that you can actually control the relay based on temperatures.


[¹] – Commands for manipulating virtual windows from within “screen” all start with a CONTROL-A character, so to create a new virtual window you would input the sequence “CONTROL-A c”, to change the current view to the next window would be “CONTROL-A n” and to change back to the previous window would be “CONTROL-A p”, and so on.  Use man screen for more details.

Using oddball ESP boards with TASMOTA – Part II (Console)

I’m not going to go too deeply into the specific hardware I used for my own project, but instead just give a couple of tips on using the Yellow board as a base for your own creations.  First of all there’s that row of red LEDs.  While they make for a neat “running light” display, there aren’t that many projects (ESP-based VU meter, anyone?) where they’d be truly useful.  In addition to sucking the life out of your battery, they can also interfere with some peripheral connections by providing a pull-up path on the GPIO pins (the single RGB LED is a common-cathode device, by the way, so those GPIOs are pulled down).  Sometimes the red LEDs are beneficial; for instance, I2C requires pull-ups and the LEDs also handily show activity on the bus, which can be an aid to troubleshooting.  However, in general, we don’t want them there, especially on a battery-powered projects.  I usually disable the red LEDs by removing the 470Ω current limiting resistors with a hot iron (why the resistors? …because I don’t have to try and figure out the correct polarity when replacing them, if I want to re-enable any of the LEDs).

If you’re mounting the Yellow board in an enclosure of some sort, you may want to desolder the RGB LED and mount in the lid,so it can be seen externally.  Be warned, because of the four leads (with the one which is the common cathode soldered to ground), this is a bit of a beast to remove, but it can be done with a big enough iron and some patience.  If you are mounting the LED to the lid, it makes sense to add a momentary switch across the boot/program select jumper (GPIO0) and mount it in the lid, too.  That will give you access to all of the Sonoff switch functionality built into TASMOTA.

Whichever way you’re powering the Yellow board, from batteries or a mains adapter of some sort, it never hurts to add a nice chunky electrolytic capacitor on the 3v3 supply line (I generally use a 470µF).  The existing SMD capacitor close to the edge of the board by the boot/program select jumper has the pads oriented just right to allow the leads of the electrolytic to be soldered on, with the body of the capacitor hanging over the edge of the PCB.  A 5v supply from something like a phone charger works well with the Holtek regulator on the Yellow board (which has rather a low maximum input voltage rating, compared with some of the more commonly available 3v3 regulators).

Using the configuration information from the previous article as a guide, you can now connect up the Yellow board GPIOs to the devices you need for your project.  The important ones for TASMOTA compatibility are:-

  • GPIO0   – Button1
  • GPIO12 – Relay1
  • GPIO13 – LED1 (the Sonoff basic uses “LED1i”)

In my particular application, GPIO13 (LED1) is connected to the green anode of the RGB LED and I also have three additional connections:-

  • GPIO5   – DS18x20 (two DS18B20 temperature sensors)
  • GPIO14 – PWM1 (the blue anode of the RGB LED)
  • GPIO15 – PWM2 (the red anode of the RGB LED)

With the current version of TASMOTA (5.11.1), the one-wire bus for DS18x20 sensors is limited to a single GPIO.  You can have multiple sensors on that GPIO, but you can’t have (for instance) one DS18B20 on GPIO4 and another on GPIO5; only one of them will show up.  If you want to have more than one sensor on your one-wire bus, you should use Theo’s specially crafted sonoff-ds18x20 binary (or define USE_DS18x20 in the user_config.h file when building your own).

The “PWM” designations for GPIO14 and GPIO15 allow us to control the brightness of the LEDs attached to those pins.  We could just as easily have assigned them as “LED2” and “LED3” to use simple on/off switching, instead.

Now, to test the operation of our newly updated ESP8266, we have basically three options:-

  • The serial port on the ESP itself.
  • The web server provided by TASMOTA
  • MQTT

DO NOT use the serial port method with a mains-powered project unless you remove external power and use the serial adapter to provide DC to the ESP.  I’d recommend that you program the ESP with the serial adapter before fitting it to any mains-powered project and from that point onwards limit yourself to OTA upgrades and using the Web and MQTT methods for configuration and testing.  Note that using a serial adapter generally doesn’t supply enough current to reliably drive multiple LEDs and a relay, so I wouldn’t recommend this method, anyway.

For either of the remaining methods, the essential reference guide is the “Commands” page of the Sonoff-TASMOTA wiki.  You should keep that guide open in your browser while you experiment.

The “console” option of the web interface provides a very versatile method of monitoring output, as well as enabling input and, together with the previously discussed configuration menus, is pretty much all you need to get your ESP project up and running.  You can input commands by selecting “Console” from the main TASMOTA menu and typing them into the input box displayed at the bottom of the screen.  The results will be displayed in the main console window.

Console command window detail

In the above example (click image for full-size version), you can see that the console was displaying occasional status messages until (at 23:56) I entered the commands:-

  • ledpower
  • ledpower on
  • ledpower off
  • ledpower

…to check the current status of the green LED (LED1), then turn the green LED on, turn it off again and finally check the status to verify that it was off (note that the final “ledpower” command was entirely spurious, as the device had already echoed an “MQT” status message in the main console window to indicate that the LED was “OFF”).

The commands to control the relay are similar.  We simply replace the “ledpower” with just “power”.  Typing in “power” on its own will return the current status, while “power on” and “power off” do exactly what you’d expect and also return a confirmation message, just as the “ledpower” command did.

Controlling the PWM drive to the red and blue LEDs is only very slightly more complicated.   Entering “pwm” gives us the status (of both PWM1 and PWM2), while entering “pwm1” or “pwm2” followed by a numeric value between 0 and 1023 will produce an output brightness in proportion to the value entered (and, as before, the console will show a message confirming that the action has been completed).

00:24:15 CMD: pwm
00:24:15 MQT: stat/Plug1/RESULT = {"PWM":{"PWM1":0,"PWM2":0}}
00:24:21 CMD: pwm1 350
00:24:21 MQT: stat/Plug1/RESULT = {"PWM":{"PWM1":350,"PWM2":0}}
00:24:35 CMD: pwm2 799
00:24:35 MQT: stat/Plug1/RESULT = {"PWM":{"PWM1":350,"PWM2":799}}
00:24:38 CMD: pwm
00:24:38 MQT: stat/Plug1/RESULT = {"PWM":{"PWM1":350,"PWM2":799}

Reading the one-wire sensors is even easier still.  As long as there are no hardware or Main menu, showing temperature readouts.configuration issues, the temperature(s) will always be displayed at the very top of the TASMOTA main menu.

Using the console command line is slightly more obtuse, though.  The temperature readouts are a part of the TASMOTA status group, so you could type in the command “status 0” to get a full display of all possible status items.  However, if you do that, you will see an extremely verbose listing of 10 separate lines of status, with the temperature data being displayed as status line “STATUS10…StatusSNS…”.  Luckily that line hints at the command we need to use to get just the temperatures and nothing else.  The magic incantation is “status 10” and typing that into the console input box will return just that single “StatusSNS” line with our sensor data, including the sensor’s unique serial number and an indication of whether it is reporting in Fahrenheit or Celsius, as well as the temperature value itself.

00:55:11 CMD: status 10
00:55:11 MQT: stat/Plug1/STATUS10 = {"StatusSNS":{"Time":"2018-02-01T00:55:11","DS18B20-1":{"Id":"011590E534FF","Temperature":2.87},"DS18B20-2":{"Id":"031590A618FF","Temperature":1.87},"TempUnit":"C"}}

There are a number of “setoption” commands in the TASMOTA toolbox and, for those who might need it, the command “setoption8” will change the temperature display units.

setoption8 0 – sets the units to Celsius

setoption8 1 – sets the units to Fahrenheit

That’s it for the console commands for now.  Next time we’ll look at doing the same thing again, but utilizing MQTT from a remote machine, instead.