Category: IoT

OpenBeken with Globe Electric Smart Plugs

I needed some more home automation friendly outlets, and my preferred Sonoff S31 outlets are hard to get at the moment. It also seems that the S40 has been released as a replacement, but moves away from the ESP micro-controller. This got me looking for what I could get locally.

The Home Depot carries the Defiant series, which when I looked up the details on the FCC website it seemed like a great candidate having an ESP32 inside. However, it seems that the eFuse has been flipped to prevent any further firmware updates. I then moved on and found a sale price of $22.99 for a 3 pack of the Globe Electric Smart Plugs.

Now these plugs do not have an ESP device in them, but a WB2S module. Some folks take advantage of the fact that this is pin compatible with an ESP device and will just swap in a whole new logic board. However, you can also use OpenBeken which I’ve done before. Since these were pretty cheap I picked up 3 boxes (9 plugs).

These plugs are fairly compact and you can fit two in an outlet (top and bottom) if you wanted.

The first thing we need to do is open these. This is fairly easily done using a pocket knife and a little bit of patience / prying. After doing a few of these I got pretty quick, a minute or two to open them. I captured a short video I put up on YouTube showing this process.

Now that it’s open, you can remove the exterior case entirely and you have access to the internals. The micro-controller was easy to spot, it is on it’s own tiny circuit board.

You can see why some folks are simply removing the entire controller board and swapping in a compatible one with a more friendly chip to program. However, with OpenBeken we have the option of reprogramming this chip with some firmware to give us local only control (via Home Assistant).

At the top you can see this is a WB2S board, and the chip is a BK7231TQN32. For the most part this chip is referred to as a BK7231T.

We’re going to need to hook up 4 wires to this to reprogram it, 3.3V, GND, Tx and Rx. Let’s figure out where those pins are.

This is the other side of the board, and if you look carefully you can see at the bottom edge we have starting from the left side BAT, GND, IRX, ITX. These are the 4 pins we need to connect with. Thankfully we can access each of these from the bottom side of the board as the controller board slots into the main circuit board on it’s edge.

Not very pretty, but it gets the job done. The wires are from some stripped ethernet cable and I think they are 26AWG – fairly small. While this was convenient for me to connect some wires to, upon inspection it seems the only reason there is any solder here is to support the board-to-board connection, I’m pretty sure all of the actual interfacing to the circuits is on the other side.

Someone on the Elektroda forum seems to have done the first work on one of these plugs. A lot of people using OpenBeken have used the CloudCutter project to reprogram things without wiring anything up, but this seemed more complicated to me and not guaranteed to work with all devices.

My first attempt I used the same software as I had previously. The only change was to download a different firmware because this is a different module. Unfortunately I goofed somewhere and when flashing the device it failed, then it was no longer responsive to my attempts to connect via serial at all. It may be a brick now, boo.

For my second attempt, I did more reading about the ESPHome support for BK72xx chips. There is quite detailed information about flashing the chips, and it seems to strongly recommend you do not use the old tool I had previously used. There is also a section there on un-bricking things which I’ll have to try later.

Thus I picked the ltchiptool – and installed it under Windows. The easy way to do this on Windows was use the Microsoft Store to install “Python 3.10” – then run pip install ltchiptool[gui]

Once installed, you can launch the GUI with python -m ltchiptool gui

While I may eventually end up using ESPHome, I decided to stick with OpenBeken and grabbed the latest OpenBK7231T_UA_1.17.800.bin from their download page. I first used the ltchiptool to download the existing flash image to confirm my wiring was working. Then I held my breath and uploaded the firmware.. and it worked.

Then it was a simple matter of repeating things. Crack open the case. Solder some wires. Hook it up to ltchiptool, download to confirm things are working, upload new firmware. De-solder the wires. Re-assemble. Now I had 8 outlets reprogrammed.

A dab of crazy glue helped re-seal the exterior cases. So far this seems just fine after a few insert / removals of the plugs.

Next we need to do some configuration. Upon first boot the device will offer up a captive portal. Connect your computer to the “OpenBK76231N_XXXXX” WiFi and visit http://192.168.4.1 in a browser. From here we can pick “Config” then “Configure Wifi & Web” to setup the Wifi connection.

Once the device is on our WiFi network, it can then see the internet which allows us to use the “Web Application” to further configure the device. You can launch the Web Application from the main landing page. I did find that it was important to access the device via IP address (ie: http://192.168.1.56) vs. by name.

Once we launch the Web Application, we can easily configure the device by using the “Config” tab, and searching for the right template from the web. I have to say this is a pretty clever way to do things.

You can see I’ve searched up the “Globe Globe smart plug” and have used “Copy Device Settings” to populate the “Pin Settings”. At the bottom of the page there is a “Save” button to persist the choice. Now if we revisit the Home page we will see the device now offers up control of the power. The button on the side of the plug also now works to toggle power.

The last thing we’ll do is connect this up to Home Assistant. The easy path here is to setup MQTT (Config->Configure MQTT) and get connect to your broker. I was left scratching my head why Home Assistant wouldn’t see these new devices – and after a lot of probing around my MQTT setup and verifying that data was flowing, I finally watched the video the explains it.

Short story was – after you’ve got MQTT setup, and the main page will show you the MQTT State is connected – you need to do one more thing to have it emit a discovery payload to Home Assistant. (Config->Home Assistant Configuration) and hit “Start Home Assistant Discovery”. Then the devices just appeared with their short name in Home Assistant.

New Thermostat – Ecobee Lite 3

I’ve had my eye on the Ecobee 3 Lite for a while. My previous thermostat was starting to show it’s age. The cloud service had been discontinued, but it still worked well with Home Assistant. However, recently it started to be colder at home than was comfortable – this turned out to be the fact that the temperature was set 2 degrees lower than the schedule?! Sure I could have worked around this, but when you can’t trust the device to do what it is supposed to do – time for a change.

I was able to get a used Ecobee 3 Lite pretty much new in box for $60 from someone locally. This is a good price, but I’ve seen it as low as $50, but often higher. Keep in mind the new price is currently only $179.99, so it is a reasonable cost even new.

The Ecobee comes with a white plastic shield you can use to cover up any unsightly holes left in the wall from the previous thermostat. As my drywall patching skills are finally getting to an acceptable level, I opted for a ‘clean’ install and patched and painted the mounting damage.

Since I’d already sorted out the whole C-wire thing for the previous smart thermostat, it was just a matter of removing the old one – and installing the new Ecobee. Included with the Ecobee is a magic box that will let you fix your missing C-wire problems, it is involved and you have to mess with the wiring in your furnace but at least they have a solution.

Here is a photo of my existing wiring.

I’ve got C, W, Y, Rh and G. Following along with the installation manual, it’s easy to map this over to the Ecobee wiring harness.

The old -> new wiring

  • Rh -> Rc
  • G -> G
  • Y -> Y1
  • W -> W1
  • C -> C

Once this is done, you just snap the thermostat in place. I thought it was pretty cool that it detects the wiring setup and confirms as part of the first start experience.

This is a good way to confirm that you’ve got at least good connections to each of the wires on the back plate.

Next up it’ll send you off to download the app and sign up for an account with Ecobee. For now I’m using the ‘cloud’ service but I will say that I wasn’t a huge fan of how much information it wants to gather about your location, size of house, number of people in the house. I can rationalize why they might use that information to provide a better experienced – but we are talking about just a thermostat that is going to turn your HVAC system on and off. It does sound like you can disable it’s internet connectivity and run with just local and you can get by fine.

I do have it integrated with Home Assistant. It seems that Ecobee is no longer offering the ability to create new API keys so the only way to connect is via the HomeKit integration. HomeKit really wants to use mDNS to discover things, and running HomeAssistant (HA) inside of a docker container can make this tricky. Most solutions suggest you run the container using the host networking mode --network:host, but I opted to give my HA a macvlan IP address.

I probably should have done this a while back. Suddenly my HA install was able to find all sorts of compatible devices on my network. The Roku Ultra, the HD Homerun, my printer, and the Sonos speakers. While I was able to make all of these integrations work previously the auto-discovery wasn’t happening.

I was able to easily integrate via HomeKit without any Apple devices in the mix. From the thermostat itself you can enable HomeKit integration, then just use the 8 digit value from the screen to connect to the HA integration.

Of course, many of my IoT devices also live on an isolated network, and I haven’t quite figured out how to get the mDNS reflection stuff to work yet. Hopefully at one point I’ll get there, and maybe that will let me shift the thermostat and Sonos speakers to the IoT network as well.

It’s been a couple of days, and the Ecobee has been working fine. It’s integrated into Home Assistant via HomeKit and as a bonus I now get both temperature and humidity readings from the thermostat. It also look pretty nice on the wall – and no more surprise cold wake ups. The thermostat user interface is touch screen and feels pretty intuitive.

 

pOwn your IoT – OpenBeken

If you buy something, you expect to own it – this means being able to decide what it’s doing or not doing. If you can’t open it, you don’t own it. I think this is really important when we consider IoT devices that you add to your home. You should have 100% control over your light switches, not be reliant on some company to allow you to manage them.

In the past I’ve used Tasmota to replace the firmware in some commodity devices with good success. I wanted a new light switch and found the Martin Jerry S01 switch, so I ordered one. Unfortunately when it arrived, I opened it up and discovered the control module was no longer an ESP 8266 – but a Tyua CB3S device.

Some searching turned up the OpenBeken project. This is an open firmware that supports a number of Tuya devices. It appears to be possibly inspired by Tasmota which I found attractive, but the fact that there was a way to run open firmware on this device was the big draw.

Let me back up a little. Opening the MJ-S01 is quite easy. I used a putty spatula (thin metal blade) to pry the side clips. There are 4 clips, two per side.

Once you’ve got the clips released, you can easily remove the switch plate. There is a metal grounding plate you’ll have to un-hook from the switch plate. There is a cable with a 3 pin connector to separate the switch plate from the base, this is optional but makes it easier to work with the switch plate that has the controller.

I went further and removed the screws holding the circuit board to the switch plate in order to see the other side where the CB3S is attached. In the picture above you can see the blue circuit board in the middle. You don’t need to do this extra disassembly as the row of 6 pads exposes the right pins we want to work with.

In order to flash new firmware, I need to find and connect 4 pins: 3.3v, GND, TX, and RX. To identify these I referenced the Tuya documentation on this module which listed the pin outs on the module. Using my multi-meter to check connectivity, I was able to map the pin outs on the module to the pads on the circuit board.

Now it’s a simple matter of heating up the soldering iron and hooking up some wires to these pads.

A bit ugly, but it works. Now I can test that I’ve got things correct by hooking up just 3.3v and GND. Success! When I power on the device this way I get the expected blinking LED, and I can long-press the button to enter setup mode. Getting the stock firmware into AP (access point) mode – I see the expected “Smart_XXXX” access point become available to my laptop WiFi.

Next we get to experience the adventure of setting up the application on Windows. I’m going to gloss over this because it’s both a bit complicated and also my experience is likely to be different than yours. We are trying to get the GUI based flash tool installed. I needed to install some .net framework, and tell Windows it was ok to run this un-trusted application. I was lucky that my USB<->serial dongle was recognized by Windows and showed up as COM6.

Assuming you are able to run the app, get your serial connection sorted out, and provide 3.3v power to the device – we are very close to being able to get things going. One note: I connected the TX of my serial device to the RX of the CB3S board, and RX to TX. Crossing the connection seemed to work for me.

There is quite a bit to unpack from the image above. First you can see that my Serial UART was correctly detected and setup as COM6. I expect your configuration here will be different, and I hope it works easily for you but USB serial devices and windows can be frustrating.

The second key thing is to pick the right “chip type”. The CB3S contains a BK7231N, thus I selected that from the list of supported chips. I suggest you then “Download latest from Web” which in my case upgraded me from version 606 to version 670.

At this point everything seemed OK, but I wanted to proceed cautiously. The CB3S apparently enters programming state upon power on. I had this all hooked up, and tried “Do firmware backup (read) only”. This just worked for me, and I was greeted with the screen capture I took above showing “Reading success!” – so I knew now that I had at least all of the right connections made. The other thing that reading the firmware did was give the tool something to parse and discover the Tuya settings, this data appeared in a second dialog box and provided a JSON payload for me to save away.

Now we need to be brave and flash the latest version of the open firmware. This time it seemed to get stuck trying to enter programming mode and I needed to very (very) briefly disconnect/reconnect power to reset it. This worked great and I held my breath while it flashed.

I had not checked off the box “Automatically configure OBK on flash write” so once it was flashed, I then did a second operation of “Write only OBK config” to write the discovered values (that JSON payload). I didn’t need to configure anything, the tool had already initialized the values internally after the firmware backup step.

In theory, I have the original firmware downloaded to my machine in case I want to revert. If you care about this, maybe track down that file and save it. I personally don’t think I’d ever go back.

One more power cycle, and I’m very happy to see a WiFi access point appear named “OpenBK76231N_XXXXX”. Connecting my laptop to this I’m able to visit the IP address of the gateway (http://192.168.4.1) and am greeted by a very Tasmota looking web page to configure the device.

Now I can remove my patch wires from the solder pads, re-assemble the device and test that things still work end-to-end (they do). While there are similarities to Tasmota, things are quite different. There isn’t a built in timer facility which I was hoping for, but it turns out that via some simple scripting I can program in a timer schedule. You can even change the built in web UI via scripting which is pretty cool.

There is also very nice Home Assistant integration built in. The CB3S controller appears to be more snappy than the Tasmota ESP-8266 based devices I have, so while this device wasn’t what I expected when I ordered it – with a bit of work it seems I’m in a pretty good place.

Footnote: There is a forum which seems fairly active on the OpenBK firmware and various supported devices.