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Docsy Blog

This is the blog section. It has two categories: News and Releases.

Files in these directories will be listed in reverse chronological order.

2log App for Users in Google Play Store

The user app is in the Google Play Store!

Hey folks!

Just because there hasn’t been a new blog post for so long doesn’t mean we’ve been sleeping - quite the opposite! A lot has happened and I’m really excited to share some news with you.

2log App in Google Play Store

The 2log app for end users is finally available in the Google Play Store. That means: No more APKs to download! The process of submitting an app to the App Store is unfortunately not trivial - I had to learn that painfully. That’s why I’m pleased that the app can now be downloaded from the stores for Android and iOS.

Shelly Plug S no longer available

I have heard from several sources that the old Shelly plugs can no longer be ordered and that the successor, the Shelly Plus Plug S, can no longer be opened and flashed so easily. But no need to despair - Shelly has worked on its firmware and now supports outgoing websocket connections out of the box. I am already in the process of coding an interface for this. If everything goes according to plan, the Shellys will no longer need to be flashed manually and can simply be integrated into the 2log system as they come out of the box. Isn’t that great?

Our community has grown

I am also very pleased that the 2log family has grown. Many new people have joined our Discord and are busy building their 2log workshops. Maybe there will soon be a guest post with a workshop presentation? Stay tuned!

2log is ready for 380V devices 🤩

The frequently asked support for three-phase current machines is there!

Hello Friends!

I got a lot of emails and was asked many times, but now it’s time! There is now finally a prototype for 380 volt three-phase machines. Now it is finally possible to integrate 380V workshop machines up to 16 amps into the 2log system. Larger lasers, milling machines and band saws are now no longer a problem.

How does it work?

Unfortunately, there are no ready-made smart 380V plugs that can be easily flashed with their own firmware. That’s why we had to do a little trickery. The switching is done by a three phase contactor. The contactor is switched with a single 220V phase. The Shelly Plug S in its socket housing is rather unsuitable for this job. That’s why we have now extended the firmware to support the Shelly 1PM.

The Shelly 1PM

Please make sure you purchase the Shelly 1PM with the ESP8266 in the round housing and not the square Shelly 1PM Plus, which has a square housing. In terms of features, it is comparable to the Shelly Plug S. The measuring sensor is the same, it also supports the full 16 amps and is also much easier to flash than the Shelly Plug S. Accordingly, the Shelly 1PM together with the DIN rail adapters can also easily be used for single-phase 220V machines. The 3D printed DIN Rail adapters allow the direct installation of the 2log switches into control cabinets and thus additionally protect against vandalism. The firmware and documentation of a 2log switch based on a Shelly PM1 is now online!

Ok, Back to the 380V

The Shelly 1PM now switches the 3 phase contactor and is wired to measure the first phase. This is not optimal, but allows at least for symmetrical loads a reliable measurement of the current consumption.For most machines, however, this should not be a big problem.

How do I build my own?

What do we need?

  • Shelly 1PM
  • 3 phase contactor
  • DIN Rail Housing
  • Some Feed-through terminals

How are the components wired?


You have now learned how to build a 2log switch for heavy current machines using a 220V Shelly 1PM and a three phase contactor. If you have any questions or feedback you are welcome to join our Discord channel.

The 2log app for iOS!

Many bugfixes and a 2log app for iOS!

Hi folks!

It’s time again for some news from the 2log lab! After Corona unfortunately got me too, I’m happy to finally announce some updates.

The last critical bugs are fixed!

Especially the provisioning, i.e. the setup of the devices via the app, unfortunately worked very unreliable in the past. The reason was the automatic switching of the WiFi connection via the native Android or iOS APIs. This problem is (kind of) fixed now. The user must now change the WiFi manually when prompted to do so. It’s a bit more cumbersome now, but it works reliably.

The new Dot PCBs are here - and they work!

The new PCB layout (v3.3) has finally solved the ground plane problem! That means all card types supported by the PN532 can now be read with a 2log Dot. Also new is the possibility to use a 1.3" I2C OLED instead of the RFID card reader. In the future, QR codes will be displayed on it, which will allow logging in via the 2log user app.

The 2log User App - now also available for iOS!

This point pleases me the most, because it really cost a lot of nerves. But the 2log app is now finally available for Apple users. The app is the basis for the concept with the QR codes, which I want to push further with version two. All infos about the 2log User-App can be found at

So, when will version 1.0 finally be released?

Soon, very soon - I promise! Basically everything is there now. From now on it’s just about testing and finding (and fixing) the last minor bugs.

But this should not stop you from using 2log! Even if there is no official version 1.0 yet, the most important features are implemented and tested sufficiently. Therefore: Use, become part of the community and join our Discord channel!

Until then all the best and stay healthy,

The documentation for the tally sheet is online!

Now a first beta version of the tally sheet is finally available.

Hello out there!

Today I have some news for you again! With the cold season I also have a little more time and motivation that benefits the 2log project. As always I am very happy about feedback. If there are any problems, just contact me via eMail or Discord.

The new tally sheet is here!

I am happy to inform you that now the tally sheet has been released as an Android app. You can use it to account for snacks, drinks or work materials in your community. For example, you just take a coke from the fridge and pay afterwards on the tablet with your 2log card. Without any cash - either with the card or the 2log app. Be sure to try this out and let me know if it works for you!

Alternative Device Provisioning

In addition, the documentation for manual device provisioning has also been added. As mentioned in my last blog post, the 2log admin app sometimes still has problems when provisioning the devices. Therefore I have added an alternative possibility to the documentation. Dot or Switch can now be connected with a Linux shell. Read more…

Many bugfixes

I strongly recommend all users to update the container - I merged some new bugfixes from the dev to the main branch today! Among other things there were some problems with the initial password reset. These are fixed now!

News from the hardware

The board with the fixed ground plane will probably be in my hands on wednesday and I will test it directly. This would also finally solve the bad support of different card types. Furthermore, the new board has another goodie on board: It allows to solder a small OLED display instead of the RFID reader. This should soon make it possible to log in to a machine without a card at all, using only the app.

So stay tuned and check the blog regularly. Have a good time and stay healthy!

See you next time,

Version 1.0 will be released soon!

The tests from the beta phase have been very successful so far, so that we can assign the first release tag with version 1.0 soon!

Again, way too much time has passed since my last blog post. Nevertheless, I am happy to announce some news!

The last known bug of the current 2log Dot PCB is solved. A failed ground plane caused that many RFID card types could not be read. A new, revised version is currently in the final iteration and will be released very soon. Also the firmware versions for Switch and Dot from the current main branch work absolutely reliable after setup.

Only the provisioning of the hardware via the app sometimes needs a second or third attempt. Restarting the hardware or the app solves the problem in most cases. It’s a bit annoying, but not a showstopper.

Dear friends, I am very happy to say: The official 1.0 is within reach!

Since I started to promote the project a bit more actively I decided to set up a Discord server. (Use the following link to join: Questions or problems can be discussed there directly. In addition I want to set up a forum in the near future. Until then just use the Discord server if you have questions or problems!

Switch Firmware for Shelly Plug S is now Release Candidate!

Firmware for Shelly Plug S is now Release Candidate!

It took way too long, but now the last bugs of the official firmware for the Shelly Plug S are fixed! The current firmware has passed all long term and field tests, so that it got the tag 1.0-RC1 in the main branch.

This also means that the free open source version of 2log is as good as ready and can be used very soon!

But that’s not all - there will be a hardware update for the 2log Dot in a few weeks! Besides some changes, which hopefully solve the EMV problem for some card types, there will also be the option to install an OLED display instead of the RFID reader for the first time. This should make it possible in the future to use the Dot either with the cards or with the app, by scanning QR codes.

Hello world!

It has taken a long time, a lot has happened, but now it is finally ready. 2log is open source and can be used freely by everyone!

It’s the Haxogreen 2022 - the first milestone I have planned for this event is reached: The 2log landing page is finally online!

There might still be some dead ends here and there and probably this landing page will never be really finished. But what’s there so far is a good start and hopefully helps to get up and running on your own.

As always, feedback and cooperation is highly appreciated.