YAT and ESP8266

For some years now I’ve been using my own serial terminal for ESP8266 development – not any more!

As fervent readers will know, over a period of time I’ve developed software for the phenomenally useful ESP8266 and you can find out more about that, here, suffice it to say it is likely the most comprehensive code for general use of the ESP8266 out there, focussing on MQTT communication so to be particularly useful for central controllers with MQTT access such as “the script” makes available via Node-Red on a range of microcontrollers, for example for my own home control setup.

Update 17/10/2017 – New release today


Probably the easiest way to set up boards with my software is to use a serial terminal and for some years I used my own as I just could not find a decent, free Windows serial terminal that would handle things like odd baud rates (the debug info on the ESP8266 is 78K) and store macros etc in a nice environment – and yes, I’ve tried many such terminals – Putty, Kitty, Advanced Serial Terminal, Realterm, Termite.. the list goes on.

Until this week I was happily using my own version when disaster struck. Due to sheer incompetence on my behalf I lost the source code for my own serial terminal. No big deal as I’ve not updated it for some time.  As it happens I was never totally happy with the terminal, it did a LOT but it was based on Microsoft Visual Basic – did not handle comms errors too well and I could not dynamically resize it – however, it was colourful and did really well for itself.

The disaster started me off to look at serial terminals, not expecting much – when I spotted YAT – i.e. Yet Another Terminal.

I have to tell you – it is very good – and ideal for the job – oh, and free.


It has some limited text colouring which is nice (I’ve asked for more), an unlimited set of macros which can be single line or multi-line and they can be paged – this, for me, is an absolute essential. The program can be resized, baud rate can be anything you want, it recovers BRILLIANTLY and automatically from COM port problems (like pulling the lead out of the FTDI), colours and fonts are easily customised…

It won’t take me long to fill up that list of predefined stuff on the right!!

HOWEVER – for the purposes of the kind of codes we use – there are a couple of issues with this – it wants to interpret \r\n sent in a string – or leave it out – I can’t find a way to pass that through – I’ve put in a bug report on this to the author.  Just be aware of that.


26 thoughts on “YAT and ESP8266

    1. I have seen and used Coolterm – thanks for that. Personally I don’t think it is a patch on YAT. But depending on one’s needs it may be worth investigating.

  1. Hi all,

    Tried YAT but install fails with the annoying and unhelpful message – install failed please re-run. I know this is a windows issue BUT…

    Does the install just ‘create’ the .exe in a location? If so, can someone tell me where to get hold of the executable?

    Really have not found a good alternative to ‘Petes Terminal’ so far!


    1. Hi Ron,

      Is this possibly happening on a WinXP PC? In that case, it’s a known Visual Studio Installer issue as described at https://sourceforge.net/p/y-a-terminal/bugs/369/. Solution: Download the appropriate binary distribution from https://sourceforge.net/projects/y-a-terminal/files/ and follow the instructions in the !-ReadMe-CompatibilityWithWindowsXP-OnlyUseThisBinaryDistributionIfInstallerFails.txt file.

      If this is not happening on WinXP, I’d required some more detailed error description, which you could directly post at https://sourceforge.net/p/y-a-terminal/bugs/.

      Best regards,

      PS, taken from YAT Release Notes:

      > For up-to-date systems, use the compact package “…(32-bit).zip” or “…(64-bit).zip”. (Windows Installer and .NET are already installed on up-to-date systems.)
      > For offline installation, use a full package “…_with_.NET…zip”. (Windows Installer and .NET are included for installation.)
      > For Windows XP, use a binary distribution. (The YAT installer is no longer compatible with Windows XP.)

      1. Thanks for responding.

        This is windows 10. I’ve had it before – it seems to affect some .msi installs, but not all.

        I’ll gather what info I can and send direct.

        It is documented in various forms online, but all attempts to correct the situation have so far failed. It is not necessarily anything to do with Yates.

        I’ll keep trying but it does get frustrating.


  2. Pete,

    Any chance of getting a screenshot or two of your predefined commands?

    I saw that you had a few set up…. and probably have several by now…


  3. Hi all,

    I have just completed a preliminary version YAT 1.99.75 providing two of the requested changes:

    Additional setting and keywords \!(FramingErrorsOn|Off|Reset) that allows configuring the serial COM port behaviour on framing errors. Useful when e.g. changing baud rates (feature request #321).

    Auto scroll of the monitor view is not only suspended if one or more lines are selected but also if the scroll bar is moved away from bottom (feature request #323).

    Peter and ‘bcatalin’, I have just sent you the preliminary version via dropbox. Let me know if the changes work as expected. The others, if you also want the premliniary version, let me know your email (e.g. via the SourceForge mail infrastructure) and I will make it available to you.

    By the way, I not always that responsive and quick with implementing change requests. I just happened to be preparing the next official release 1.99.80 when this discussion started off and I considered your input worth to postpone 1.99.80 in favor of adding the two requested changes.


  4. Thanks for the heads up Pete

    I’ve just downloaded it and giving it a try out as I type.

    I’m not sure where you are these days but if you’re back in the chilly NE, Newcastle Maker Space is helping with the eDay6 event at Gateshead Central library this Saturday. Not as big as Maker Faire but always a interesting day out if you and Adrian have a few spare hours.

    1. Argggghhh. I’m not back until Tuesday!!! And Aidan isn’t back until the same time… Sorry Tony, would have loved to come. Anyway I’m there over the winter if there’s anything interesting happening.

    1. YAT is optimized for “engineering, testing and debugging of serial communications” as well as “simple command sets of e.g. embedded systems” whereas Tera Term as well as PuTTy are optimized for terminal emulations. So it depends on your use cases whether YAT may be the better choice than Tera Term.

      1. Well, debugging ESP boards definitely comes under “engineering, testing and debugging of serial communications”

  5. Pete, thanks a lot for your enthusiastic review of YAT! Hope it continues to fulfill your requirements, Matthias

    PS: Your feature request for highlighting totally makes sense, though it may take some time until I manage to implement this.

    1. What more could you ask for – a word from the author… will look forward to improvements in future. See comment by BCATALIN below?

    2. I’ve another request.. I THINK – the predefined text – right side – inserts a carriage return at the end – would be good if that was optional (or if you could enter /n or similar) – the reason I say this is – what if you want to add a partial command… for example {mytt_host:”fred”} – it would be nice if the left of that up to and including ” were in one button to speed up sending commands which have variable arguments….. I might be wrong but I don’t see how to do that now…

      1. Several options to achieve this:

        Go to Terminal > Settings…> Text… and change the EOL sequence (terminal-wide setting).

        Use a keyword (extract from minimal-help [F1]):
        > Send EOL sequence “OK\!(EOL)”
        > Do not send EOL “OK\!(NoEOL)”

        Press [Ctrl] when sending. Only works with “Send Text”.

  6. I’ve installed it and is fine. I like that now I can see the boot messages. I need it once and the my terminal didn’t supported this feature. If I have a long log there is way that I can scroll up and not the go to the end on every new received log message ?

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