Tag Archives: Raspberry Pi

Raspberry Pi Zero WiFi

Raspberry Pi Zero WiFiI should have just entitled this “Raspberry Pi” as it keeps expanding (now covering the rest of the Pi boards – but keep reading).. as you will see, the title is a little restrictive given what we’ve done over the last few days. Friend Antonio over Italy and I (still stuck here in the frozen wastes of the Northeast of England) have been working quietly in the background on making the script compatible with the new Raspberry Pi Zero WiFi (RPiZW) having already managed to get it working on a range of boards and operating systems including RPi2, RPi3, Debian, Xenial, various Orange Pi boards, various FriendlyArm boards, the Odroid C2 and more.

At under a tenner, no-one can claim this tiny WIFI enabled RPiWZ is going to break any records. It is slow. very slow compared to a Raspberry Pi 2 or perhaps an Orange Pi Zero... and at first attempt I nearly gave up after waiting a whole day for my script to run (and fail) - something that can take maybe an hour on more powerful single board computers such as the RPi3 or the Odroid C2 etc.

However, having failed to get the script to run on the official Raspbian distribution for this board, for a variety of reasons, we next tackled DIETPI. Here, this slimmed down operating system comes into it's own and the PI Zero WiFi runs a lot more swiftly than it does with stock Raspbian. Still, by lunchtime yesterday I'd stopped the script due to various errors. By late last night however, with a little manual injection I had everything running on this tiny board - Apache, PHP, Node-Red with all my usual Nodes, MQTT, Sqlite, PhpLiteAdmin, Ha-Bridge, MC and much more, all with no manual intervention (just as well, given the time it takes).

This weekend while I was out shopping for a new milk-frother, our friend Antonio over in Italy was busy working on some last minute amendments to the script which, you'll recall now runs on a range of devices and systems including Xenial and Debian. We’ve now completed the  updates to the script, including the ability to run on the RPiZW.  The sheer size of the RPiZW (or rather lack of it, being exceedingly thin) means you could fit this board, able to control a house, on the back of an LCD display and have the whole thing mounted in a reasonably slim wall-mounting box. The Orange Pi Zero on the other hand has that large Ethernet connector which means a slim case is out of the question.

There is of course competition for this board, the Nanopi Neo Air is actually smaller (different format of course, being square) - and no doubt a lot faster - but like the RPiZW it has no Ethernet. One issue I've had with many boards is that of WIFI reliability. Up to now, the WIFI on the RPiZW is rock-solid - just as well, as it doesn't have hardwired Ethernet capability (well, not without some soldering or a compact-size-defeating USB dongle). The NanoPi on the other hand works well and is way better technically but I'm not 100% happy about the WIFI on the latter. All of this could change of course with future software updates.

Raspberry Pi Zero WiFi: Here’s what I did (total time 4 hours -  VERY little of which I was actually doing anything – well, watching YouTube videos actually):

  • I grabbed the file DietPi_v145_RPi-armv6-(Jessie).img
  • I used SD Formatter to format a 16GB card then Win32 Disk Imager to blow the image onto the SD card.
  • I plugged the card into the RPiZW and powered the board up, plugged into a screen – and with keyboard and mouse connected via a USB hub.
  • I started up the Pi – that takes a little while and it eventually wants you to login as root (initial password dietpi).
  • As per initial dialogs in DietPi-Config, I set up the WIFI.
  • The board went off to do some downloading and came back to the DietPi-Software - I swapped from DropBear to OpenSSH Server and lighttpd to Apache2 - but didn’t install anything else.
  • At the end of that I could get into the board remotely using WINSCP and no longer needed the keyboard and mouse.
  • I copied the script across to the root directory – ensuring it was in Linux format (Line feeds only) and that it had execute permission.
  • It went off and automatically set up a PI user with password “password”. I logged into the board (using WinSCP) as user  pi. I copied the script across again and once again made sure it had execute permissions. I ran the script.
  • Several items were downloaded. I waited patiently until the main menu came up. I accepted all defaults but added HA-Bridge.
  • I was asked for a user name (user) and password – and an admin name (admin) and password… (you can opt out of that now and leave defaults if you like) and at that point the script – as you’d expect – went off for 4 hours (using a half-decent microSD from Samsung) doing it’s own thing. And yes, watching the WEBMIN setup DOES feel like watching paint dry.
  • At the end of all of this – I rebooted the board – and that was the end of that – a perfectly working RPiZW.

Something that has come out of this – is the importance of SD speed… I’ve always known this but NEVER has it been as obvious as it is here with this slower board. 4 hours – recall I mentioned an earlier attempt which failed but also took longer. Well, now I’m using a decent Samsung microSD.

Raspberry Pi Original: Which brings me to the Raspberry Pi – not the 2 or 3 but one of the originals. The script appears to be working perfectly now even on pre-Pi2 boards with full size SD card (Raspberry Pi © 2011.12). Sadly when I was using those I was not aware of the need for the best SD and THIS install took 7.25 hours – if you plan to try one of these – get a decent SD! Still – all working so an otherwise useless Pi is now up and running.

Raspberry Pi Zero: On a whim, I took a copy of the microSD I used on the RPiZW and dropped it into the lowly, cheap and cheerful Raspberry Pi Zero (the one with nothing) – I then took a USB adaptor and plugged it in, with one of those really cheap unbranded WiFi USB blocks at the other end.  I plugged in power, waited, checked for new IP addresses and LO AND BEHOLD that was online too!

Raspberry Pi 2:  I tested the modified script on the Pi2 and as well as being a darn sight faster to install than the units above – it does work well.  I did however notice that the yellow Node-Red GPIO node does not work – possibly something missing in DietPi. However – there’s a great utility called GPIO which gives you full command line access and I’ve now added that as an option to the script. I’ve tried GPIO access including PWM and it all works a treat as Pi user.

git clone git://git.drogon.net/wiringPi
cd ~/wiringPi

The above it what I added… then use GPIO – now, with the –g option, the pins correspond to the actual connector which is nice – so for a nice dim LED on GPIO13

gpio –g mode 13 pwm
gpio –g pwm 13 20

Not tried that on the Zero but I assume it will work as well. If anyone knows why that yellow GPIO node sits at “connecting” do let me know. Remember in all of this we’re using the DIETPI image – NOT original Raspbian – which IMHO is a little heavy handed if you don’t want a graphical interface.

Things are looking up.

Raspberry Pi backupAnd now for something completely different: Meanwhile I thought you might like to see this Raspberry Pi battery backup  (not for good reasons) -   I bought this a couple of weeks ago and it turned up today. 4 brass spacers and it fits onto my Raspberry Pi 3 a treat.

But – pull the power out – and the Pi reboots – who on EARTH dreamed this up!!! They claim 9 hours of backup but no good if power loss causes a reset… worse -  I bought it from Europe at £9.49 and I COULD have bought it from where they probably got it from in the first place at £8.73 and no postage. Oh well. I’m assuming I got a bad one – surely they could not have designed it this way. Anyway, it has a 3800maH battery and it all fits perfectly on the back of a Pi.  On the FRONT of my Pi I have an LCD display and the whole thing was intended to form the backbone of my updated home control in Spain when we go back there in April. A clue to the problem may be that there is a small yellow power indicator on the Pi, suggesting the pack might just be putting out insufficient voltage for the Pi + LCD. So – I tried it with a Raspberry Pi 2 on it’s own – same result. Just thought you’d like to know in case you were thinking of buying one of these. THIS looks GOOD (Thanks Antonio) – any experience of this??  I have some goodies from another company coming in the next couple of weeks which look promising as uninterruptable supplies– more on this soon.


Toying with HA-BRIDGE

Thanks to readers in here I’m having a play with HA-Bridge to act as a device gateway between my home control (generally ESP8266) devices and Amazon Echo.

I’m only scratching the surface and haven’t gotten past “Alexa, turn X on”, “Alexa turn X off” and “Alexa set X to 30%”  but it’s a start and hopefully someone in here will fill in the blanks.

So, assuming you have an Amazon DOT or Echo (at £49 the DOT is the best toy I’ve bought for ages – just bought another one for the house – as this one is hiding in my office)…

The BEST way to control gadgets by voice up to now IMHO is using our own Node-Red software and an HTTPS certificate – but then – it’s not trivial as has been discussed elsewhere (unless you’ve done it before) to get the HTTPS and Amazon talking to each other.

So I played with simpler solutions (I like to try everything) but just recently decided to have a go at HA-Bridge – now – this IS EASY if you don’t go to the wrong repository etc…

First things first – Aidan was playing with this and he could not get anywhere as he had an old version of JAVA on his Raspberry Pi – he solved THAT problem as such. I found that I had to use root access for ALL of the code below.

    echo "deb http://ppa.launchpad.net/webupd8team/java/ubuntu xenial main" | sudo tee /etc/apt/sources.list.d/webupd8team-java.list
    echo "deb-src http://ppa.launchpad.net/webupd8team/java/ubuntu xenial main" | sudo tee -a /etc/apt/sources.list.d/webupd8team-java.list
    sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys EEA14886
    sudo apt-get update
    sudo apt-get install oracle-java8-installer

So that's Java up to version 8. On a NEO AIR I got an error message when running “java –version” until I rebooted.

Now to install HA-Bridge - easy -  go to your PI directory on the Pi or similar - make a directory - called, say, "habridge" - and enter that directory. I grabbed the JAVA file directly in Windows and copied it across-  giving it execute permissions - not sure if that was necessary but I'm just repeating what I did.

All I did was grab the JAVA file from here.

So the general idea is that this Java file will run - and give you a web page in which you can create and run "devices" that the Dot or the Echo will recognise. But it will want to use Port 80 by default (normal web page port) and I of course have a web server there...  I tried running it - failed due to lack of permissions - so I ran it as ROOT - that failed due to the port being in use.

sudo java -jar -Dserver.port=82 ha-bridge-3.2.2.jar

I ran this - note the reference to port 82 - and lo - it works - ok - another matter getting it to run from power up but we’ll come to that.

Ok so THEN I discovered that my MQTT installation – Mosquitto did not include the client tools… so…

sudo apt-get install mosquitto mosquitto-clients -y

Off I went to a browser :

HA Bridge

Ok, here's the bit that floored me - this might save you a little work. I used MANUAL ADD to add these devices - here's one of them... these will respond to on, off and a value - and send MQTT messages accordingly. That's it - all you then have to do is tell Alexa to search for new devices - and use them.

So what we have here is only marginally better than the simple node-red node - i.e. we now have % lighting control - who is going to show us how to develop this to do temperature and other stuff!

HA Bridge

If you don't need user and password for your MQTT  (-P and –u) - don't use them.

The only thing that appears fairly useless is the middle item - intensity control - which could be used for lighting or heating. So "turn office television to 25" works - you get the value 25. "turn office television up" or "down" shifts the value by around 25% - and that's GREAT for lighting but no use for heating - I would want an actual value to set the heating to that value - but up and down to shift the temperature by - maybe 1 degree.

You can in fact say “turn X up by one”.

SO - easy voice control - create lots of devices... this whole operation other than blogging it took merely a few minutes and thanks to readers who pointed me in this direction.

This software does not seem able to control responses – you get “OK”  - how then would you ASK the thermometer to return it’s current value!?!?! Well, you can’t so there is still life in our HTTPS solution – but this is VERY easy to set up.

Having now followed the instructions here and here (see “writing a unit file in the latter link) made a “unit” startup file – I now have the whole thing running from power-up on the same Pi that runs Node-Red and Mosquitto.

Essentially here’s what I ran having created a UNIT file as per the first of those two links above.

sudo systemctl enable habridge.service

sudo systemctl  start habridge.service

That’s it – program runs – survives power cycle.

Here’s another explanation of how to do this! http://xbmcnut.blogspot.co.uk/2016/10/installing-ha-bridge-on-your-raspberry.html

So much to learn, so little time.


Home Control 2017

Introduction (Latest update May 10, 2017)

HomeSick of reading about other people’s home control? Want to make your own? Got some electronics and software experience? You’re going to LOVE THIS! Rock-solid home control – low cost, DIY.

If you’ve read my early blogs you’ll know that Aidan Ruff and I have been working in home control since the late 20th century. Together, we ran an electronics R&D company for many years and one of our products was a home control system called APPCON.

That range of products  achieved much coverage in the UK tech press at the time and many loved it but the design involved spouse-unfriendly WIRES – bad mistake. So now we’re back – this time for fun –  with a vengeance!

Home Control 2017

Add to that lot above, the SI1132 unit which returns light values for visible, UV and IR - and a host of other I2c boards around the corner.

By the time you look at the diagram above it will likely be out of date as new features are added – thankfully there’s a manual along with source code and diagrams available online and kept up to date. This is all free incidentally and without warranty. Software, diagrams, board layouts… and this blog has a range of articles on the subject.

The diagram pretty much says it all – a Raspberry Pi (2 or 3) or similar,  talking to your PC or smartphone via a range of potential technologies – and using a powerful communications protocol called MQTT over WIFI to talk to small yet incredibly powerful ESP8266 units – these can be bought very cheaply and programmed – or you can take our board designs and have some boards made in China if you really want to DIY (we do!).

There are no real limits to the number of boards you can have talking to the central controller – that is down, in the main, to your WIFI network which could cover one room or extend across the globe.

In my own system I have 3 properties talking to each other – one in the UK, one in Spain. No matter where I am I have full access – great fun, great utility, low cost. Who wants to pay £50 to control a light! This is definitely aimed at the DIYer.

In the coming link there is a complete project, suitable for Windows development using the ESP8266 “Unoffical Development Environment” for the ESP8266 – but that won’t stop Linux users from bending the makefile to their will!! Currently using SDK version 2.1.0

There is a DOC file here which is fully up to date with all commands – this blog entry just shows a selection. Even if you ignore or don’t understand the source and just download the ROMS available – you’ll be able to keep up to date via OTA (over the air updating) – and you’ll need that manual!

You may also need some new – and very useful skills as you’ll see the term Node-Red appear very often throughout the considerable range of blog entries in here – this is by NO means a single item – there’s a Nextion-based, prize-winning WIFI touch display blog and a range of discussions (and there are LOTS of valuable comments) throughout the blog – enjoy learning and please do feel free to share knowledge – there is SO much more we can do with this.

Update on flashing ROMS here:  https://tech.scargill.net/esp8266-home-control-update/  - Blog reader Jay has written a great blog on setting up the programming environment for Windows.

ESP8266-terminalWhat is missing from the diagram above is my first experiments with SPI. Using up GPIO13 to 16, I have a 320*240 display working experimentally as a fast scrolling terminal on the ESP8266. Handy for debugging the system without tying up your PC monitor.

How useful this is depends on how many other pins you need! We need an ESP8266 with many more IO pins – I guess that will be the ESP-32…Or of course you can use my “universal peripheral” – using a simple Arduino Nano clone at sub £2 from China, talking to the ESP8266 or indeed any I2c setup.

Background: I’ve been using ESP8266 chips since they first came out – and I have the development kit for their new ESP-32 –just waiting for some decent software tools to emerge but right now the ESP8266 is a lot of fun and that’s part of what keeps this all going.  In the summer of 2015 I made myself so visible on the ESP8266 front that I was invited to be part of an Espressif-led delegation to MIT in Boston for the FAB11 Conference – demonstrating the ESP8266 with MQTT and Node-Red and how to build this into practical systems. I’ve also recently been involved in a project in Spain for the MOD researching ESP8266 and IOT security and more.  If you wish, follow my ramblings on the subject of control using these chips in THIS blog – and also on Twitter (@scargill), Facebook (esp8266wifi and IOT pages) and LinkedIn.

Nextion DisplayRegular readers will know that for some time now, the ESP8266 boards have been turning the world of IOT upside-down. I’ve long-since scrapped various radio designs (NRF24L01 etc.), blighted by short range or lack of network ability - and have gone “hell for leather” into using these boards.

Home ControlThe original plan involved an Arduino Mega as a “master controller” and Arduino “slaves running over an NRF24L01 mesh network. Here in this link is one of my first attempts at blogging on the subject – along with pictures of the original “Appcon” system from back in the ‘90s.

The original Arduino-based system worked well worked and indeed controlled heating and lighting for a couple of years at my home, but the controller went out of the window when the Raspberry Pi 2 came out which was dirt cheap but with more than enough power to control a house or ten. Now of course we have the RPI3 and other exciting boards such as the tiny FriendlyArm NanoPi Neo.

Hardwired to Ethernet (or WIFI if you prefer), the system allows for a comprehensive wireless home control setup  and to answer any questions about ESP8266 reliability – with the code you’ll see in here,  I can say with a lot of experience, that the ESP8266 units given reliable power, are rock solid – stunning considering the price.

ESP-12The ESP8266 boards provide a REALLY low-cost entry solution into the world of IOT making it possible to create in the simplest sense an Internet-controlled LED for under £2 (it could just as easily be a 2KW heater of course for a little more outlay).

There are a number of variations on the ESP8266 boards, the first shot at this being the ESP-01 – a simple board with power, a couple of IO lines and serial in and out. The thing is – they all use the same chip and that particular board (the ESP-01) is very I/O and FLASH limited – and for no good reason – the ESP-12 and variants for example have access to the A/D converter, several IO lines, have more FLASH memory and cost the same amount!

The only downside to the latter is 2mm spacing pins but for VERY little you can buy adaptors to 0.1” – or of course use a board that will take the ESP-12 or the ESP-12E (which is the same – but with a few extra essentially useless pins) – same price. There are also a number of ESP-12-based boards today which offer 0.1” spacing. For this reason I’m giving up on supporting the ESP-01 with it’s limited FLASH memory though as you’ll see in another blog entry,  with a steady hand and fine soldering iron it is trivial to replace the old 1MB Flash on the ESP-01 with a cheap 4MB Flash making it more compatible with ESP-12 etc (well, you still have hardly any pins to use).

Oh, here’s a link to the various source files. Here are original Board files designed by Aidan Ruff. No guarantees – not even any guarantee they won’t change or disappear if we find bugs. Since this article was started I’ve added I2c and a software serial port (optional) on GPIO4 and 5 to control Nextion serial displays directly. Instructions here may not be fully up to date but always check the WORD document in the repository. You might also want to look at the Nextion WIFI touch display board and links – I discuss another control board in there as it can be used for general purpose. This board has neither a relay nor power supply (other than 5v to 3v3 conversion) on-board but it’s a better job for general use.

Also check elsewhere in the blog to see what we’ve done with the Itead Studio Sonoff boards and their plug-in-the-wall remote mains socket. All of this stuff works together as a whole or you can cherry-pick.

I’ve added i2c to the ESP8266 software which as you’ll see in the picture at the start of this blog as made a big difference to the number of supported devices. What a roller-coaster this has been an a great way to learn all about i2c – I’ve improved the original Espressif offering a lot!  I’ve recently added version numbering to power up info and a powerful debug command and also, the power-up info indicates which GPIO is currently used for Web setup and which pin for the visual LED or RGB LED indicator.  At the time of writing the code is using the latest Espressif SDK version 2.0

tmpA4AFThe later PCB you see here was designed (by Aidan Ruff) for my award-winning (ok I had to get that in) Nextion Serial Terminal which  in April 2016 grabbed second prize at the esp8266.com 1st Annual awards. The latest update to this board includes the option to use an RGB LED as the status indicator – something I see as becoming the standard – once you have a selection of colours an intensities to indicate status, all of a sudden a normal LED looks boring.

The Boards

For the reasons stated I’ll discuss here the ESP-12 (and variations, ESP-12F being the latest with a marginally better antenna) as that is my favourite sub-module - but the same code applies to other variations where pins allow. We have working software – and circuit boards to go with it. For reasons best known to my pal Aidan we called this original the Hackitt & Bodgitt board. We have a new board version with an RGB LED as the status indicator on GPIO13.

If you are in any way unhappy using 240v AC mains power, you may want to give this a miss or fit one of those 12v to 5v down-converters so cheap and popular on EBay – I do this to power them from a solar-charged deep-discharge battery in some cases. This version does NOT tie GPIO16 to reset (the saving in power on this board wasn't really worth the bother – and note that GPIO16 is usable as an output). Again in the latest version we’re moving to using GPIO16 as the default relay output – freeing up GPIO0 to be an input only (programming – and web-setup).

Front view

Here is the rear view. Note the MOSFETS on the back (this is looking straight through hence letter reversal)


Note that a particularly nice feature of this board is that it can be programmed from a standard, cheap 5v FTDI.

So in terms of “Features”, the diagram at the start of this blog entry says a lot – but for clarity:

  • Mains-powered WIFI controller board
  • FTDI-compatibility
  • Accommodation for solid state or mechanical relay output
  • Temperature sensing using DS18B20
  • Temperature and pressure sensing using the BMP280
  • Temperature, pressure and humidity sensing via the BME280
  • Temperature and humidity using the DHT-22 or DHT-11
  • All signals brought out to edge connectors
  • Uses inexpensive power supply (or DC/DC converter) available on EBay
  • De-bounced input with automatic debounce and messaging
  • Analog in for checking battery state etc., will handle up to 20v
  • Several Outputs expandable via I2c
  • RGB WS2812b output on most pins able to handle 300 or more serial LED STRIP
  • 3 outputs for high definition PWM – with MOSFETS to control LED STRIP
  • Talks WIFI and MQTT - ideal for being controlled by a Raspberry Pi or similar using, say, Node-Red
  • Flashing status (software supports both simple LED and serial RGB LED)  indication that the unit is functioning and has the correct time which it maintains internally in between updates*
  • Second serial output to support Nextion displays (see the Nextion WIFI Touch Display project)
  • Software mono-stable out for use as a watchdog
  • Outputs can be timers for watering systems for example
  • OTA updating from internal or external website
  • I2C support for an ever-increasing range of devices including a new Nano peripheral which adds truly inexpensive I/O, PWM, analog inputs and servo control
  • Hitachi LCD and Seeed OLED support
  • 16-channel 12-bit PWM support via I2c
  • 4-channel 16-bit ADC support via I2c
  • A new NANO-based peripheral via I2c with GPIO/PWM, ANALOG in and SERIAL OUT
  • A new SPi-based terminal (which fits on the ESP8266)
  • and more to come…

* (The time comes from an MQTT broker, for example using a Raspberry Pi or similar running Node-Red – see below)

** I now use Node-Red on the Pi to do thermostatic control. Consider the thermostat code to be legacy.

And another board: we’ve also put together a board for the Nextion displays - but WELL suited as a general purpose board and it is detailed on the WIFI Nextion  blog entry but I’ve included a picture here for reference. I can see a variation on this one being my main board eventually – just needs an add-on with a couple of relays and 3 MOSFETs to make it a perfect development board.  There is a cap on the reset line so that typically an FTDI is able to reset it automatically. Note: The current revision of the board has extra grounds and  4 way sensor connector (DS18B20, DHT22 etc.). Note that an even later version optionally uses an RGB LED for a status indicator – WAY better idea.

Nextion control board

The Controller

ESP-12We have chosen to commit to a communications protocol called MQTT as reliable code for this is freely available, MQTT “brokers” are also freely available and once you spend a little time on the subject it is both easy and the obvious way to control stuff in a network. Lookup “tuanpm mqtt” on Google.

As MQTT is so central to this, I’ll go into this in a little depth.  There are many ways you could have units talking to each other – a mesh network, a radio network, polling etc…over time I have come to see MQTT as the ideal tool for home control because it is simple, the tools are free and it WORKS.

Essentially an MQTT broker is a piece of software – a server if you like,  available online or (my preference) on the likes of a Raspberry Pi inside your network) which monitors incoming messages and sends messages out according to who they are for. Addresses are simply text. Messages are simply text. MQTT clients (software that receives MQTT messages for one unit and sends messages out to an MQTT broker) are available freely for the likes of Arduino, ESP8266 and in Node-Red. It really is all very simple once you get playing. So MQTT is an incredibly simple yet powerful format comprising a message “topic” and a message “payload” both in the form of simple text. Units can “subscribe” or listen for specific topics. A great way to play with this is to use an online free MQTT broker – and something like MQTT-SPY which is a free “client” which runs for example on a PC.

The ESP-12-based controller has a number of inputs and outputs which can be controlled equally well by MQTT commands or serial data - by the current software.

To talk to the unit wirelessly (WIFI) via the popular MQTT message protocol, a message can be sent to the topic “toesp” to send to all units in the network or to a specific unit by prefixing the topic with the unit ID, or example “kitchen_light/toesp”. The only difference between these two topics is that the former will go to all units yet never elicit a response from any unit, the latter will go to unit “kitchen_light” only and MAY, depending on the context, elicit a response from unit “kitchen_light” – unit ID is simple, programmable text.

Whatever controls these boards(Raspberry Pi?)  should now send

topic: toesp

payload: {heartbeat}

every minute. All the boards will see this - and all will pre-set a counter in themselves - which if allowed to drop to zero will re-initialise the MQTT code. In the event that boards lose the WIFI for some time, they may reset their WIFI  - then reset the MQTT code. Reset is used only as a last resort and the software can handle up to two SSIDs in case you happen to have two access points. If one fails it will try the other.

Hence in theory they should be bullet-proof. In practice they are bullet-proof unless of course the power goes off. Last summer in Spain I endured horrendous WIFI and power issues and the current code stood up to this and has done ever since – learned the hard way. That experience is also why I worked hard to ensure the OTA works so I can update the units remotely.

Each COMMAND or payload starts with an open brace and ends with a closing brace (my choice, kind of like JSON). In the case of MQTT, this information is stored in the message “payload”. For serial, there is no “topic” – just the message (payload) which you can fire into the serial port at 115k baud.

An example of a simple command might be to turn output 4 ON (output 4 goes to pin GPIO4).


It is possible to send multiple commands at once by separating them with semicolons. i.e.


So to use serial – this is all that is required (newline delimiter) – for MQTT – the topic should be as referred to earlier and the payload should be in the format shown just above.

clip_image002[4]For more on MQTT go here. http://mqtt.org/

I chose to use a Raspberry Pi 2 (you could use 3 but 2 is ok) as my controller – and chose to use Node-Red as the controlling software when this was a project unknown to most  – turns out I picked a winner as Node-Red is now embedded in “Raspbian” on the Pi and is hence guaranteed a well-deserved and bright IOT future. It is also wonderful and really NOT hard to use. Want to play with Node-Red without even doing an install? https://fred.sensetecnic.com/ – enjoy.

The following document details the commands the units will respond to – the actions which will occur along with any return serial message or MQTT message created as a result of the incoming command. But please – read the manual.

The Pins

Here we see a drawing of the ESP-12 board, please note there is a question mark over the positioning of GPIO-4 and GPIO-5 – on many units, these are reversed.

You are looking at the FRONT of the unit with the metal cover visible.


Note: Contrary to the diagram, in prototyping I’m using a 1k to pull GPIO15 down as it’s still a grey area (some say the board won’t program unless GPIO15 is held down) – it does NOT have to be fully grounded and as you’ll see in fact I added PWM output on it (March 26, 2015).


The ESP-12 units operate on 3v3 – NOT 5v. Extensive experience suggests a good 3v3 linear regulator fed from, say a 5v supply provides more reliable results than a 3v3 switched-mode supply – but that will vary with suppliers. I’ve recently been part of a project where we used WELL over 100 ESP-01 units all attached to one 20 amp switched mode power supply – they worked… but I prefer per-unit linear regulation.

We done just that in all our own boards, using a switched-mode 5v supply (or DC/DC convertor for 12v use) with a 3v3 linear regulator. I suspect most complaints about these boards boil down to power supplies. I can honestly say – that having used countless ESP boards since they came out – I’ve not once come across a bad board!!

To talk to these units from any 5v system through serial, you should ensure that inputs to the ESP-12 never exceed 3v3 (resistive divider). Typically the serial output will work just fine fed into, say the serial input of a 5v Arduino – I have NEVER had any trouble with this at 115k baud. Simple resistive level conversion can easily be implemented so that a 5v FTDI will talk to the serial without issue. In practice I’ve yet to see a 5v FTDI destroy an ESP8266 but if you go without the divider, be it on your head.

Certain pins are special and in particular, grounding GPIO-0 on power-up is used to trigger “flash” programming of the chips and also used to put the units into access point mode for setup – so you should be aware of this. When designing outputs I base all of mine on Vcc. So for example when driving a LED…


Why do I do that? Well, when the unit powers up – GPIOs are all input – and if you preset them to “1” on power up you’ll not get any flashing lights as the units boot up.

Below describes SOME of the commands currently implemented.  We have both WEB-based and SERIAL setup, full MQTT integration and the development focuses on using NODE-RED – specifically but not exclusively on Raspberry Pi (I’ve installed Node-Red on many SBCs and consider it as standard as adding Apache and PHP.  We’re using the free and excellent Mosquito for the MQTT “broker” on the Pi (i.e all units connect to this “broker” by address and password” and the broker stores and releases on request stored messages – hence any unit can talk to any other unit as well as making requests of the Pi).

The manual that comes on BitBucket with the code is way more comprehensive than this blog in terms of commands.

Command set

Controlling and monitoring outputs

The potential outputs are GPIO0 (that’s the one on the board with the relay – future boards will not use GPIO0), GPIO4, GPIO5, GPIO12[1]  GPIO13[2] and GPIO16. These are referred to as OUT0[3], OUT4, OUT5, OUT12 OUT13 and OUT16. You can also use GPIO2 as an output via a command – normally it is used with the likes of temperature sensors.

Typical outputs respond to the commands {outX:1} , {outX:0} etc where X is the GPIO number. If requesting the status of an output this form is used {out0?}

There are 3 variations on this:

{out13} (GPIO13) by default should not be used as its main purpose is that of a LED “status” indicator (though you can override that) (see the relevant command).

{out0:X} responds to the following for X:

0 – off (if command “invert=1” then the state of that output is inverted (for positive-based relays) – see the invert command…

1 – on (see above)

2 – on from dusk till midnight (see above)

3 – on from dusk till dawn (see above)

4 – on from dawn till dusk (see above)

5 – under local thermostatic control – see relevant command (see above)

6 – timer for output 0. Another parameter determines ON time in minutes – i.e. {out0,6,100} sets the output on for 100 minutes.

There are a set of related commands for reading the state of outputs – these are {out1?} {out2?} etc. Should unit “kitchen_light”  be asked for the state of out1 – the MQTT message sent back will be in the form

topic: kitchen_light/fromesp/out0

and the payload will contain the appropriate value.

Outputs can be inverted by the invert command by setting bits 0,1 and 2  etc., in the invert command. See the manual.


We’ve added PWM onto 4,5 and GPIO15 using the latest Espressif library which allows for up to around 95% duty cycle at very high resolution (14 bits) for the cheap 12v serial RGB LED STRIP though we have brought that down to 100 smoothly transitioning levels – but decent ones (i.e. non-linear – with more emphasis at the bottom end for smooth transition). Attached to a logic-level control MOSFET you can drive a 12v LED strip with this – initially off, use the command {pwm:X,Y,Z,I} where X,Y,Z are 0-99 for duty cycle and I is false if you want instant transition, or any value if you want a smooth transition.

For example if I =50 (50ms) then 0-99 would take 5 seconds. A lookup table is used to get a reasonably smooth fade (needs work).  Due to the Espressif library, you can get up to around 90% or so duty cycle at value 99 – but you really would not notice the extra on a light. Note also that the PWM even when off i still running – so if you run PWM with a board, don’t expect reliable SERIAL LED operation as the PWM has a minor effect on really critical timing as needed for serial LEDS.

Heating controls

In controlling heating, the unit will generally use the internally connectable (on GPIO2) temperature sensor DHT22 (which also handles humidity) or the Dallas DS18b20 or DS18b20p. These heating commands are deprecated as it is a lot easier to do heating controls in Node-Red.

It is possible right now to set the maximum temperature, the fall-back temperature, frost temperature and 2 on-off times per day locally. Of course using an external MQTT control the possibilities are endless.

Relevant commands are (X is general a value, degrees C or minute after midnight):








Time settings

The units are able to keep time but clearly do not have a source of time – this can be provided to each unit separately or more sensibly to all units at once.

{time:X} standard Unix time value the number of seconds since January 1970

{dawn:X } number of minutes past midnight considered “dawn” or street lights off time

{dusk:X} number of minutes past midnight considered “dusk” or light up time

{When they power up, units attempt to log on. This is an ideal time to send them the time.


The internal analog to digital convertor reads from 0 to 1.024 volts and outputs a signal accordingly. This can be read by the {adc?} command.


From the serial console, we can view various settings by using the command {debug}.

Temperature and Humidity

The relevant commands here are {temperature?} and {humidity?} They will send out, by return, for example in the case of unit 999 :

Topic: 999/fromesp/temperature

Data: X where X is in degrees C

Humidity follows the same format but is a percentage.


If we want the unit not to respond to a command but to pass everything on to the serial line to control, say an Arduino, use the EXT command followed by a string  – this can be used part way through a multi-line command if required.


The two outputs will be switched and the command {out0:1} will be send out of the serial port.

Of course, one COULD send these commands off to an Arduino – OR you could send them off to another ESP-12 with it’s WIFI disabled… the logic of that? It’s cheaper than an Arduino and faster!! You can develop in the C language for the ESP boards using the unofficial Eclipse development environment.


and you can learn more about my own work at https://tech.scargill.net


Setting up for WIFI

There are commands to set the unit ID (defaults to “999” note this is a string not a number), ssid, ssid2, pass, pass2, mqtt_host, mqtt_port, mqtt_user and mqtt_pass. In each case surround the argument with double-quotes.



You can also set “desc” for a short description and “attribute” for any short message like “Dallas” to indicate what facilities the board has.

The above can also be set by WIFI.  Turn the device on and immediately short GPIO0 to ground AFTER power up for several seconds. This will put the unit in to web setup mode. Have your laptop, tablet or phone browser log into Hack-setup and go to to set everything up.

There are two SSID and passwords – the idea being that if the unit fails to get through to an access point it will try the second one, if that fails it will go back to trying the first one etc.


If for any reason we want to reset the device, the {reset} command will do that.


GPIO14 is an input. We can read the state with the {in14?} command.

It is also de-bounced and you can read (and simultaneously reset) the count using the in14_count? command. The inbounce:X command will let you set the bounce value in milliseconds.

When the state of the input changes (de-bounced) an MQTT message will be send out in the form of TOPIC: XXX/fromesp/in14 where XXX is the unit ID and  MESSAGE: 1 or 0

There is also a bounce value for in2 – i.e. {in2_count?}

Manual Override

If we wish to manually over-ride the status of GPIO-0 – for example wall control of a light – set {override:1} to do this – the input can then be attached to an on-off switch and will over-ride the output for a length of time in minutes determined by “override_time”.


One of the more useful features of the board is to be able to directly control an array of WS2812B LEDs. Right now, overall control is implemented including programmable fade-in and fade-out and a “rainbow” effect. However, buffer space is available to implement full individual control of up to 900 LEDs (warning use separate 5v supply for these – current can be up to 5amps for such a run). Note you cannot currently run PWM and RGB LEDS at the same time. Initiating PWM starts a timer that disrupts RGB timing and a reboot is needed between these. I’ve contacted Espressif about this.

The command takes the form of:

{rgb: port,red,green,blue,number,duration}

So if we want to go to bright red over 10 seconds and you’ve attached an array of 20 serial LEDs to the output GPI12, the command is:


And that will happen and we can do other things while it is fading in. The duration is a 32 bit number.

For amusement purposes we can also try {rainbow: port,number_of_leds,duration[,timer speed in ms]}

A neat toy: requires 60 RGB LEDs and can run on a port pin… a clock… {clock: port} if is 255, the clock is not running else runs on the relevant port.

If you want to just light up SOME LEDs in a strip – the command {rgbset: start_led, number, r, g, b} will let you set up various LEDS to various colours and the command {rgbgo: port,number_of_leds} will start the ball rolling. That number should not exceed 300 (not for any reason – I could have made it larger).

If you want to play with animation… {rgbstart: port,number_of_leds} will clear a command buffer so you can interactively add sequences {rgbadd: start_led,number_of_leds,r,g,b,milliseconds} and when you want it all to end, {rgbstop}. These commands can be sent via serial of MQTT.


When the board powers up it sends a message “esplogin” and in the body the the name if its ID with a slash after it.. so “999/”. This can be read to send the board, say, the time. See the next section.

I’ve implemented {sleep:x} where x=microseconds (32 bit number) hence 10000000 is 10 seconds. You need GPIO16 attached to reset and that just isn’t worth the saving on this particular board but it’s in there for completeness. This is deprecated.


BlynkOriginally we’d planned on using something like OpenHab for home control and of course anyone armed with the software can do just that. But for our purposes we like Node-Red as it is extremely flexible and becoming more powerful by the day. If you have a Raspberry Pi2 or better – you can run Node-Red on that but it also runs on Linux, PCs etc.

Node-Red allows one to “program” using visual boxes via a web interface– so an MQTT input box can respond to a particular topic, you can then do something with that and send a message back – or elsewhere – or maybe send a TWEET, or store some info in a database or send an email – honestly it is VERY simple to use and very powerful once you get to grips with it.

If you look at my earlier blogs I’ve written about graphing locally, using data pulled in by Node-Red and stored in a MySQL database with ease. There are alternatives – I’ve written a “node” for Node-Red to let you simply send data to Grovestreams.com and others have written nodes for the likes of EmonCMS which has some very pretty dials.

Here’s a screenshot of my Emoncms data and yes, the battery is really flat – due to this being solar charged out in Spain – and it is 6am in the morning – clearly yesterday wasn’t that sunny.

EmonCMS used at Bedrock in Spain

Node-Red has a timing module… when lets you trigger things at certain times. It also has available a suncalc which sets a flag when it is sunset. I’ve improved this significantly in a node called BIGTIMER (see http://flows.nodered.org/ -  check out my bigtimer, esplogin and grove nodes– my contributions – for example – “npm install node-red-contrib-esplogin”) -  to produce an output directly suitable for the current design – to log the boards in and to tell them about the time, sunset and sunrise.

The esplogin node can send time updates when Node-Red powers up and on a regular basis (every 12 hours)to all boards – but also send to a specific board on request, and all boards will happily send that request when they power up – so typically a few seconds after power-up the boards know what time it is and what dusk and dawn times are.

Here’s what it looks like in action.. MQTT coming in from boards in the form of a json payload (purple), esplogin node in yellow doing the time/dusk/dawn updating and outputting the relevant MQTT back to the board (or in the case of time top-ups – all boards). The outputs from esplogin are, in order..

1. MQTT output

2. Output for a MYSQL database (legacy)

3. Output to a straight text logging file

4. Output to a SQLITE database



All boards subscribe to “toesp” – and to a version of that with their name (ID) prefixed – so for example fred/toesp. That way I can talk to any board – or all of them.

When the board first powers up – it sends…  in the case of board “fred” which has description “my board”

Topic: esplogin

Payload: {“id”:”fred”,”desc”:”my board”,”attribute”:””}

Desc and attribute at not that important but can be shoved away in a database.  So that sets off the esplogin node  putting info to it’s outputs – I only use the SQLITE output and that ends up in a database – that’s up to you but my setup is in the Raspberry Pi script referred to elsewhere.

So assuming the node gets that login – it will send a bunch of time info back to the ESP board in question – and will then do that every day to all boards. This stops the boards from watchdog resetting and ensures they always have the correct time without needing a real time clock etc.

See the time, dusk and dawn commands – the ESPs can be updated though right now this isn’t necessary as the home control software on the Raspberry Pi is doing all the work.

How to get all the software the easy way

In order to use these boards effectively – you’ll need a Linux setup (a Raspberry Pi 2 or 3 for example) with MQTT, NODE-RED and preferably other stuff like PHP, SQLITE etc. Personally I’m not a Linux lover!!! And so I like things to be easy – so we made a SCRIPT. You can grab a Raspberry Pi(2) and put everything on there. The script works with JESSIE version of Raspbian. I made this script for “Jessie”. Follow the instructions precisely or it will not work. You must be user PI and NOT ROOT. Read more about the script here...  and

I use the Pi2 – after testing many boards this seemed a while ago to be the best for the job IMHO and for reliability use a good SD such as Samsung EVO and to make life really easy. If you have a Pi3 all the better.

For controlling and monitoring – I am currently using the Nextion (serial) touch display boards for the wall and vary between using Blynk Android/IOS app for remote control, the node-red-dashboard and ImperiHome.  All work well depending on your requirements.

You’ll read about all of this stuff elsewhere in the blog – use the search facility – there is a LOT of info.


[1] GPIO5 (out5) can be manually over-ridden by the input and the “override” command.

[2] GPIO13 (out13) is generally used as an indicator to show that all is well. It activates on receipt of the correct time either serially or via MQTT and will flash briefly once every couple of seconds from there on. This activity can be disabled by a command. Increasingly we’re using a serial RGB LED on this pin to provide more comprehensive status info.

[3] GPIO0 (out0) is special in that it responds to more than “1” and “0” and can be used as part of a heating control system. Ultimately we will scrap using GPIO0 as an output and merely use it for programming and setup. GPIO16 makes a good relay output as it is not much use for other types of output.

Haptic feedback – when the board is being used in “Nextion” mode – we use GPIO12 as a beeper – simply fasten one of those cheap round haptic feedback devices to it and glue that to the back of the board. Also note that with limits (the line buffer is only 80 characters in length) you can concatenate commands so that for example if you want to turn GPIO12 on and get feedback as to the state at the same time {out12:1;out12?}  - note the two payloads are joined together by the semicolon.

But the REAL source of info on commands is in the WORD manual with the project – that is where you go to keep fully up to date.




General Update

tmp11DFThe last couple of days has been interesting – we’ve been checking that the Raspberry Pi 2 script works properly – it turns out that it simply won’t work if you have any kind of root access to the Pi. I’d not realised by by giving myself SUDO access in winSCP – rather handy for editing files, I’d given myself the same access in the terminal – and hence all attempts at the script failed. Today after starting afresh with the November 2015 Jessie image from Raspberry Pi (NOT the Noobs setup) – and running as Pi user, the script (despite warnings) operates perfectly, installing Apache, Sqlite, Mosquitto with web sockets and Node-Red with a host of nodes including my own.

In other events, the ESP8266 code referred to elsewhere in the blog has taken a leap (not yet online – I’m off to Spain for a couple of weeks and I’ll get onto that on my return) and now handles (thanks to Richard Burton for his help) OTA.  Still working on OTA from an external site.  We’ve added OTA setup commands to the web interface.

Most importantly on the above we’ve found and modified a library to give a software second serial port able to run at 56k – hence enabling direct Nextion display interaction on an un-modified ESP-12 for example. I already have a display device with buttons controlling other ESPs on the network via MQTT commands – this could be so powerful and will allow for remote control display panels all over the place.

tmp762BThe Sonoff device continues to work well with our software, waiting to find out how much FLASH it has on-board to ensure we’ll be able to work with that,

Sunny SpainRight now I’m packing my bags as I’m off to work on a project for just under 2 weeks on the east coast of Spain near Barcelona – using ESP-12s and Raspberry Pis strangely enough so output on the blog will be somewhat reduced as I can’t take my toys with me. I’ve a new paper-white display and a fantastic new software-defined radio setup – but they’ll just have to wait for my return.

The Facebook page at www.facebook.com/esp8266wifi is seeing more Pi and review related material and I’ve decided it is time to move the non-ESP stuff off onto a page of it’s own – so please if you are a Facebook user, follow www.facebook.com/iotstuff