Very Basic SunPower and Home Assistant, no HACS

In my continuing adventures trying to add better monitoring to my SunPower solar farm, I took a slightly different approach that what seems to be the common path on the Home Assistant Options for Sunpower solar integration? thread, and instead used Apache for the reverse proxy, and skipped HACS altogether, using the RESTful integration. If you haven’t read it already, you may want to start with Getting Administrator Access to SunPower PVS6 with no Ethernet Port, which covers me earlier failure.


The first thing was getting the SunPower PVS6 administrative interface. Since I didn’t have easy cabling access, I used a $7 ethernet adapter and a TP-Link AC750 Wireless Portable Nano Travel Router (TL-WR902AC). There is a cheaper model of the TP-Link that would have worked just fine, but even at $39 it was less expensive than most of the lowest-end Raspberry Pi crazy-ass prices right now. Power for the TP-Link comes from the LAN4 port on the PVS6, and the ethernet connects to USB2/LAN. The TP-Link is configured in “Router Mode”, where it connects by wired ethernet to the PVS6 and creates a separate network for all devices that connect by wifi. If you do this, you will want to configure the TP-Link to use a network different than your home network (e.g. if your home network is, use something like

TP-Link and ethernet dongle crammed in the SunPower PVS6

At this point you should be able to connect to the TP-Link wifi and test access to the administrative interface at

Of course, the problem now is we need to connect the home network to the SunPower network, but there is some nuance… we only want the web traffic. Very specifically, we do not want the TP-Link to connect to the network and start giving new IP addresses to our home network, which is also why you don’t just plug the ethernet from the PVS6 into your home network.

I happen to have a home file / everything else server that runs on a Raspberry Pi, and already has Apache running. That server connects to my home network via an ethernet cable, so its wifi was unused and available. I connected to the SunPower wifi (SSID “sunpowernet”):

sudo nmcli d wifi connect sunpowernet password "5ekr1tp@$$"

Finally, I need to let the server know that when the destination network is the PVS6, it needs to use the wifi connection, not the ethernet connection:

sudo ip route add via 

This is a great time to mention that it would be good hygiene to setup your server to have firewall rules blocking incoming traffic from the TP-Link, other than DHCP and established connections, in case the PVS6 is ever compromised.

Reverse Proxy

While HAProxy is super awesome and you should absolutely use it if starting from scratch, I happen to have a home server that gets 5 requests per month and was already running Apache, so I wanted to do as little extra work as possible. Fortunately, Apache has a reverse proxy, and that makes this pretty easy. I setup a virtual host with the following sunpowerproxy.conf config:

<VirtualHost *:80>
        ServerName sunpowerproxy
	ProxyPreserveHost On

    	ProxyPass /
        ProxyPassReverse /

        ErrorLog /var/log/apache2/sunpowerproxy-error.log
        LogLevel warn
        CustomLog /var/log/apache2/sunpowerproxy-access.log combined

The virtual server is going to expect the HTTP request to come to a server named “sunpowerproxy” (or whatever you name it), so you’ll need to add that DNS entry pointing to the ethernet address, not the wifi address.

If you’ve done everything correctly (modules installed, site enabled) you should be able to test everything by calling the PVS6 API from a web browser, by pointing to

After a few seconds you should get a JSON blob listing all of your devices.

Home Assistant Configuration

Finally, we need Home Assistant to be able to pull the values from the proxy. The RESTful integration provides a pretty easy way to do this… here is a basic configuration to get the current power usage and overall energy, although a lot more information, including details for each individual panel, is available:

  - scan_interval: 60
      - name: "Sunpower Production Power"
        unique_id: "SPPP"
        json_attributes_path: "$.[1]"
        device_class: power
        unit_of_measurement: "kW"
        state_class: "measurement"
          - "p_3phsum_kw"
        value_template: "{{ state_attr('sensor.sunpower_production_power', 'p_3phsum_kw') }}"

      - name: "Sunpower Consumption Power"
        unique_id: "SPCP"
        json_attributes_path: "$.[2]"
        device_class: power
        unit_of_measurement: "kW"
        state_class: "measurement"
          - "p_3phsum_kw"
        value_template: "{{ state_attr('sensor.sunpower_consumption_power', 'p_3phsum_kw') }}"

      - name: "Sunpower Production Energy"
        unique_id: "SPPE"
        json_attributes_path: "$.[1]"
        device_class: energy
        unit_of_measurement: "kWh"
        state_class: "total"
          - "net_ltea_3phsum_kwh"
        value_template: "{{ state_attr('sensor.sunpower_production_energy', 'net_ltea_3phsum_kwh') }}"

      - name: "Sunpower Consumption Energy"
        unique_id: "SPCE"
        json_attributes_path: "$.[2]"
        device_class: energy
        unit_of_measurement: "kWh"
        state_class: "total"
          - "net_ltea_3phsum_kwh"
        value_template: "{{ state_attr('sensor.sunpower_consumption_energy', 'net_ltea_3phsum_kwh') }}"

Now you should have the ability to add the SunPower sensors, and configure the Energy dashboard!

The Energy dashboard in Home Assistant

Now that I have this working I will probably realize that the hass-sunpower using HACS is a way better solution, but only the RESTful integration would need to change, all of the network and proxy configuration would carry over.

Finally, if you’ve made it this far, you probably realize that it would be way better if SunPower offered a reasonable API for home integrations, instead of making people take these ridiculous steps… please let your SunPower contact know!

What’s your SunPower and Home Assistant experience? If you’re following in my footsteps (yikes), how did it go? please leave a comment, below!

Getting Administrator Access to SunPower PVS6 with no Ethernet Port

Well, if you landed on this post you either have a need to cure your insomnia or you have a very specific problem. I recently decided to become a sun farmer, and went with SunPower, which is great, but they don’t offer integrations beyond their decent but limited web and mobile apps. In particular, I wanted to integrate with Home Assistant, because… well, just because.

The main solar interface from SunPower is the PVS6 (successor to the PVS5), and by connecting to an administrative interface it is possible to pull some detailed data like specific energy output and health for each panel. The good news is the PVS6 comes with two ethernet ports, one for a WAN to connect to their servers and one for a LAN that will allow access to the administrative UI, and all one needs to do is connect to said port and then… hey, WTF? My PVS6 doesn’t have either of these ethernet ports! So, yeah… evidently there is a new version of the PVS6 that does not have ethernet ports, and the primary WAN connection is via wifi.

A blurry photo of the ethernet-port-less SPV6

After digging around teh webz, it seems that the PVS6 USB ports will work with a USB to ethernet adapter, but several people reported some adapters didn’t work. Unsure if the magical solution is the adapter needs to be USB 2.0, but I found a $7 adapter on Amazon, and it just worked. I connected my laptop to the USB2/LAN port, the PVS6 assigned an address to my laptop, and browsing to provided a web administration interface. However, PVS6 is not within convenient ethernet wiring distance, so I dug around some more and found Dolf Starreveld’s page, which included an amazingly comprehensive doc, Monitoring a solar installation by tapping into a SunPower PVS5 or PVS6. This doc starts with the assumption you have a PSV* with an ethernet connection and want to get to wifi, and with my USB to ethernet dongle, that’s what I had, so all I needed to do was mount a Raspberry Pi in the PSV6 to act as a router / bridge to my network. But while reading his doc, I noticed a mention of a hotspot interface available for a limited time after PVS6 power-up, and a link to a SunPower doc on commissioning the PVS6 via wifi… this sounded promising.

Sure enough when I scanned for wifi connections, I found a SunPower SSID that matched my system. And since my system had been on for days, it didn’t appear that the 4-hour window applied, so great news! The formula for the SSID is “SunPower” immediately followed by characters five and six of the PVS6 serial number; immediately followed by the last three digits. The password follows a similar formula, characters three through six of the PVS6 serial number; immediately followed by the last four digits. Once connected, I had the exact same access I had when directly connected via ethernet.

But the cool stuff isn’t really in the web UI, you need to call it directly. For example:

Will show all devices and panels, with a ton of data on each. Dolf Starreveld’s document has a ton of details.

Since I don’t plan to run this from my laptop, I still need to bridge the network… several people have written about using a dedicated device like a Raspberry Pi, including Scott Gruby’s Monitoring a SunPower Solar System, where he uses a very lightweight Raspberry Pi Zero W, and then a simple haproxy setup. However, I’d like to avoid another device (especially with the current price for Raspberry devices – holy crap), and my Raspberry Pi 4 file server connects via ethernet, so I’ll likely use its wifi to connect to the PSV6 and run the proxy from there. After that I’ll configure Home Assistant and likely bore you with another posting.

And, no sooner do I get to the end of writing a post when I realize that the wifi network has vanished, so I either need to find a way around that problem or else I’m adding a router to my PSV6.

Are you doing anything interesting and hacky with your SunPower system? Do you have cool integrations with Home Assistant? Did you stay awake through this whole post?… please leave a comment, below!

ESPHome Temperature and Humidity with OLED Display

For the 3 people that have been reading my posts, you know my journey from ESP8266 hacking off the shelf smart switches to creating custom devices, most of which I connect to Home Assistant so that smart devices are secure and don’t rely on the existence of any particular vendor. The next step in this journey is using ESPHome to simplify creation of custom software for ESP8266/ESP32. For my first project I created ESPHome Temperature and Humidity with OLED Display.

Why ESPHome?

Why use ESPHome instead of something like Arduino Studio? Simply put, its simple but powerful. As an example, I made custom software for a temperature & humidity reader for my bathroom that was 8 custom lines of code (which wasn’t really code, but configuration). YAML configuration files provide access to a ton of sensors, and if you need to dig in deeper with more complicated functionality, ESPHome provides Lambdas that allow you to break into custom C++ at any time.

One of the other cool things about ESPHome is, while it integrates seamlessly with Home Assistant, the devices are meant to run independently, so if a device is out of range or has no network connection, it still performs its functions.

And I wanted to learn something new, so…

Why This Sensor?

I have a few temperature sensors around the house and I also keep one in the camper van, mostly out of curiosity so I can compare it with the in-house temperatures using graphs on Home Assistant. However, I realized that when I went camping I wanted access to the temperature, but couldn’t do so without being connected at home. The old version of the van thermometer was based on an ESP8266 Garage Door opener (I never shared that posting, so sorry, or you’re welcome) and I didn’t want to update it with a display screen, as I really don’t need that for a garage door (yes, I realize something not being needed usually doesn’t stop me from building it). I decided that I might as well take the opportunity to use ESPHome since it was simple and worked offline.

It’s Time to Build

I won’t go into the details of setting up Home Assistant, but if you are into home automation at all, it is super awesome. Installing the ESPHome add-on gives enables the flashing and managing of ESP8266/ESP32 boards, and they automatically connect to Home Assistant at that point.

For the lazy, ESPHome is generally a few clicks and a little copy pasta. For this project, it’s no different, with the step-by-step details available on my Github project page.

Wiring complete on DHT11 and ESP8266 (ESP-12F) before gluing case together

For the hardware, I used the very tiny ESP-12F, DHT11 sensors, this OLED display, and a few miscellaneous components. All of these fit pretty nicely in the case, although it is a pretty snug fit, so I highly recommend a very thin wire, and this 30 Gauge silicone wire was super great for the job. Exact components, wiring diagram, and the STL files to 3D print the case are on my Github project page.

When assembling, removing the pins from the DHT11 board and soldering the wires directly to the board will allow it to be flush against the case, giving better exposure to the sensor and fitting better. The DHT11 is also separated from the ESP8266 board as I was hoping to create some insulation from any heat from the board impacting the temperature reading (not sure that work). There is a hole between the chambers to thread the wires, and I suggest a bit of hot glue to block air flow once wired.

As you can see in the photo, I used generous dollops of hot glue to hold the components in place… it isn’t pretty, but nobody will ever see it (well, unless you photograph it and blog about it, in which case still, probably nobody will see it). I sealed the case with Zap-A-Gap glue, as I found original Super Glue was way less effective.


Plug it in.

Okay, well… it’s a little more than that. The screen will alternate between showing the temperature and humidity in text format and a 24 hour graph that is a bit useless for now since I am not sure how to get the historical values to label the graph. The button will toggle screen saver mode on / off, and the screen saver activates automatically after a short amount of time.

If you want to get a little fancier, I have this sensor in the bathroom and it will turn the vent fan on (via Home Assistant) when the humidity reaches a certain level… it’s useful for anything where you want to control devices based on temperature or humidity, and even more useful if someone might want to see the temperature.

Are you doing home automation with ESPHome? Do you have suggestions or requests? Did you actually read this blog post for some reason? I want to know… please leave a comment, below!

3D Printed Case for ESP8266 and SSD1306 display

3D printed case for ESP8266 and SSD1306 OLED display

When it was clear that nobody was asking for or needed my BART Train Monitor with ESP8266 and SSD1306 display, I knew the obvious response was to invest more time into the project by creating a model for a 3D printed case.

3D printed case for ESP8266 and SSD1306 display with measurement and coins for size
The BART watcher 3D printed case

I made a few hardware adjustments from the original build, and I am using the much smaller NodeMcu ESP-12F for the board, and this SSD1306 0.96 Inch OLED I2C Display Module, which features a full text row in yellow and the rest of the screen in blue. Finally, I added a button to the project, because everything needs a button (I happened to use these).

The case isn’t fancy, but it works… the final build is approximately 1.25″ x 1.5″ x 1″ (width x depth x height), or 3.5cm x 4cm x 2.25cm for most of the planet. One challenge with the size is everything is extremely tight in the case, so I recommend using very thin wire in your build. There are two 3D models, the base and the cover, assembly is just cramming everything in and gluing the case together. I was using relatively thick wires and everything is so compressed I didn’t even need to glue the boards in place, but it would probably be a good idea to use a little hot glue to secure things inside.

The blue and yellow OLED display with BART schedule

I really like the two color display, which was more of an accident than anything as one of the original all blue displays seemed to go bad and was very dim, so I ordered replacements.

With the addition of the button, I was able to add some new functionality. A quick press of the button will toggle the screen off and pause network updates, effectively a screen saver sleep mode. Another quick press turns the screen back on. A long press will enter menu mode. While in menu mode, a short press will iterate through the menu items, and a long press will select the menu item.

ESP8266 BART Train Monitor menu screen
OLED display with BART Watcher menu

All of the source code, 3D models, and wiring instructions can be found on my Github page bdurrett/BART-watcher-ESP8266. The project still needs work to be generic enough to be useful to anyone, but since this works for me (and I don’t think anyone else actually needs this), I will likely stop further development. That said, if anyone wants to contribute, I’d be happy to collaborate with anyone!

BART Train Monitor with ESP8266 and SSD1306 display

I frequently commute on BART and wanted a convenient way to tell when I should start walking to the train station, ideally something that is always accessible at a glance. A gloomy Saturday morning provided some time to hack together something…

ESP8266 to SSD1306 wiring diagram

I had already purchased a ~1 inch SSD1306 display and had extra ESP8266 boards laying around, so I figured I would start there. Wiring the screen to the board is super simple, just 4 wires (see diagram).

From there is was pretty simple to pull the train real-time data using BART Legacy API. BART also offers modern GTFS Schedules, which is the preferred way to access the data, but from what I could tell, this would make the project significantly more difficult given some of the limitations of the ESP8266. So, I went the lazy route.

Coding was pretty simple, most of the time was spent rearranging the elements on the screen. Well, actually most of the time was spent switching from the original JSON and display libraries I chose as I wasn’t happy with them.

(early layout)

There’s a lot to fit into a 1-inch display, but I got what I needed. The top line shows the date / time the station information was collected, and the departing station. The following lines are trains that are usable for the destination station, with the preferred (direct) lines in large type, and less-preferred (transfer needed) in small type. Finally, if a train is within the sweet spot where it isn’t departing too soon to make it to the station but I also won’t be waiting at the station too long, the departure time is highlighted. Numbers are minutes until departure, “L” means leaving now, and “X” means the trains was cancelled (somewhat frequent these days).

In the example above, these are trains leaving Embarcadero for the North Berkeley station (not shown), Antioch and Pittsburg/Bay Point lines require a transfer, Richmond line is direct.

At some point I would like to use a smaller version of the ESP8266 board and 3D print a case to make it a little nicer sitting on a desk, but then again, there’s almost zero chance I’ll get around to it. If anyone is into 3D printing design and wants to contribute, I’ll give you all of the parts needed.

The code / project details are available on my GitHub page at BART-watcher-ESP8266, feel free to snoop, contribute, or steal whatever is useful to you.

BART Watcher on ESP8266 and SSD1306 OLED display
The full build of BART Watcher on ESP8266 and SSD1306 OLED display

Do you have suggestions for features you think would be cool, want to remind me that I waste a lot of time, or maybe you even want one of these things? Please leave a comment, below!

Easier Smart Devices with CloudFree

If you followed my previous posts on hacking IoT (Internet of Thing) devices to make a more secure and sustainable smart home, you may have the perception that this is an overly complicated process that no sane person would pursue. You’re not wrong, and over the last year I’ve had several failed attempts at hacking devices for various reasons from the casing requiring a saw to the programming pins being inaccessible. However, I discovered CloudFree, love their products, and think they provide a simple solution for making a smart home that is truly under your control.

Note: This is not a paid posting, I am receiving no compensation, goods, or services in exchange, and have no ownership interest in CloudFree – I am simply a happy customer.

As a quick reminder, most IoT devices require an external Internet connection to function. The problem with this is it is less secure, as a random company, often in another country (frequently China) is controlling and updating the software, as well as harvesting data. Also, if the company goes out of business, this often means your device ceases to function.

I stumbled upon CloudFree as I was looking for an alternative for the Amazon Smart Plug, which is great, but could only be controlled by Alexa, and I wanted something that could also be controlled by Google Nest, Home Assistant, a web interface, or pretty much anything. As implied by their name, CloudFree sells devices that do not require an Internet connection, emphasizing user ownership and control. This sounded perfect.

Dipping my Toes in: the CloudFree Smart Plug

CloudFree Smart Plug 2

In addition to selling third-party devices, CloudFree was manufacturing their own Smart Plug, which had a similar form factor and came pre-installed with Tasmota, an open source UI. And, at $13 it was a good deal. I ordered two and about a week later they arrived.

Setup was super simple… plug it in, connect to the temporary wifi it creates and configure it to connect to your home wifi. You can also setup passwords and things like MQTT. It took about 3 minutes and the switch had both a web interface and was fully connected to Home Assistant, making it accessible by Alexa as well.

The other details were nice, too… the packaging is simple paper and thin cardboard, and the actual device looks good and seems to have quality consistent with nicer devices I’ve seen. Oh, and it has a lot of functionality for things like tracking power consumption. I ended up ordering three more, which took a few weeks to arrive due to them being backordered.

Even Deeper: CloudFree Smart Bulb

CloudFree Smart Bulb

I needed EVEN MOAR switches, and I decided to try the one other product CloudFree makes, their CloudFree Smart Bulb. This is a pretty basic 10W LED bulb that also allows you to control the color, coolness, and brightness, again with the super easy setup and Tasmota UI. I’ve just started playing with it, so I can’t give much of a review, but it seems well-made and does exactly what I was expecting. It reads “indoor use only”, but I am tempted to try it in my enclosed light post and change the color for holidays, events, or maybe an alarm. This shipment was relatively quick, switches and bulbs arriving in about a week, and $15 for the bulb seemed like a good price.

CloudFree Wish List

I am really happy with CloudFree overall – it is a great resource for finding user controlled smart home devices. They have a bunch of third-party sensors, plugs, and gadgets that all are user controlled, no Internet needed. If I could change anything, it would simply be adding more products, ideally made by CloudFree. Specifically, I would love to find a well made light switch (ideally with a dimmer), or the holy grail, a 3-way dimming light switch. But, for what they have right now, they are great and I recommend them for anyone looking for a simple way to add to their smart home.

Have you found other great sources of secure, sustainable IoT devices? I’d love to know about them – please leave a comment below!

More Hacking Smart Home Devices with Tasmota, Youngzuth and Gosund

Gosund SW2 Dimmer with wires soldered to serial connections on circuitboard

This is a follow-up from the post Hacking Smart Light Switches and Other IoT Devices… where I installed Tasmota on a Gosund Smart Light Switch (SW1). I also installed replacement software on the Gosund Smart Dimmer Switch (SW2) and the Youngzuth 2-in-1 Switch, and since the process was pretty unique for each, I thought it might be worthwhile to share my experience.

Using TUYA-CONVERT is preferred since it doesn’t require opening up a device or soldering, but it seems like all newer devices are using software that can’t be hacked wirelessly anymore, so you will likely need to open your smart home device. Now, let’s go void some warranties!

Gosund Smart Dimmer Switch (SW2)

This dimmer switch has a nice capacitive touch panel for changing the lighting level, so it feels a lot like adjusting something on a touch screen. Since Gosund also makes the SW1 switch I started with, I was hopeful it would be similar and I could avoid soldering… not so much.

Gosund Smart Dimmer Switch (SW2), wires soldered to the circuitboard to enable a serial connection.

Like the SW1, the SW2 requires a Torx T5 screwdriver to open it. Unlike the SW1, the SW2 dimmer switch has two circuitboards in it, connected by a small cable. Reading about this switch, one person claimed it could not be hacked with that cable connected – this is not true, and I bricked one of these detaching the cable… not recommended. Unfortunately, the serial connections are in the middle of the board, so the process I used with test hook clips would not work like they did on the SW1. However, the connection points are pretty big and well-labeled, so soldering wires to them is pretty easy. Once I had connections, the process was super simple to install new software, exactly like the SW1. It’s nice when things just work!

But, of course, things didn’t just work. When I installed the dimmer the dimming functionality didn’t work from the switch. Looking at the Tasmota template details for the Gosund SW2 Dimmer, this switch requires extra scripting to function properly. However, scripting is not available in the basic Tasmota software, so it needed a different version. Fortunately, once you have Tasmota installed, switching the software is easy and only requires a web browser, selecting “Firmware Upgrade” from the web interface. Unless it isn’t so easy. Trying to install tasmota-scripting.bin from the unofficial releases failed, and first required installing the tasmota-minimal.bin to get the smallest install and then installing the compressed version of the unofficial release, tasmota-scripting.bin.gz (only the .gz version would install successfully). I used the OTA (over the air) install for the minimal software (pointed to the official OTA releases), and manually uploaded the scripting gzipped binary downloaded from unofficial experimental builds. Once installed, there are new menu options in the web interface, “Configuration” -> “Edit Script”, and simply paste and enable the script from the template page. None of this was complicated, but is also wasn’t very obvious… hopefully I can save you some trial and error.

And, the switch works great and immediately worked with Alexa (make sure emulation is set to “Hue Bridge” to enable Alexa to use the dimming functionality.

Youngzuth 2-in-1 Switch

Youngzuth 2-in-1 Switch with wires soldered to make a serial connection to the TYWE3S.

The Youngzuth 2-in-1 Switch is actually two switches that fit into the space of a single switch. When I opened the switch (Phillips head screwdriver) and started looking around the circuitboard, I couldn’t find any connection points for the serial interface. I finally hit the point I had been dreading… needing to solder directly to the chip.

The Youngzuth 2-in-1 uses a TYWE3S package and fortunately a lot of details are available on the Tuya Developer website, so it was pretty easy to figure our the chip connections. I really hate soldering, especially on tiny components next to other tiny components, so I had a margarita to steady my hand.

TYWE3S pin connections, colors showing all pins needed to reprogram

Once wires were connected, installing the software was a breeze. Configuration was also easy, with an example provided in the Youngzuth 2-in-1 template.

Full disclosure, I have not yet installed the Youngzuth switch, as I made a rookie mistake, not realizing there is no same-feed neutral connection at the switch location. Once installed I will post an update if anything required extra work.

If you have any questions or different experiences with these devices, please leave a reply below!

Hacking Smart Light Switches and Other IoT Devices

Gosund SW1 circuitboard with test hook clips on serial connections

If you’ve ever had a free weekend, a desire to create a more secure smart home, and questionable judgment, you’ve come to the right place. In this post I’ll talk about how to take common IoT (Internet of Things) devices and put your own software on them.

Disclaimer: depending on the device, this exercise can range from pretty easy to drink bourbon and slam your head against the desk difficult. Oh, and there is some risk of electrocuting yourself or setting your house on fire. So everything after this point is for entertainment purposes only…

Why Hack Your IoT Devices?

Most people creating a smart home take the easy path… pick out some cheap and popular devices on Amazon, install the smartphone app to configure it, and are good to do. Why would anyone want to got through the extra effort to hack the device? There are a few good reasons:

  1. Security: With few exceptions, most smart devices require installing an app on your phone, often times from an unknown vendor and with questionable device permissions needed. The devices themselves are tiny, wifi-connected computers, and also have software that is updated by connecting to a server in some country, and installing new software on the device connected to your home network. Having a cheap device connected to your home network that requires full access the Internet to work is bad, but it is worse when that software can be changed at any time, to do whatever the person changing it wants it to do. This could turn your light switch into part of a botnet, or worse, be exploited to attack other devices on your home network. By hacking replacing the software, you create a device that works properly without ever needing access to the Internet, lowing the security risk. You can also see (and change) exactly what software the device is using.
  2. Sustainability: Since the devices require communicating with an external company for configuration and updates, when that company stops supporting the device or worse, goes out of business and turns off their servers, your device becomes useless or stuck in its current configuration forever. By hacking replacing the software, you are able to support the device even if the company ceases to exists. And by using open source software with a robust community, you will likely have very long term support.
  3. Because I Can (mu ha ha ha): Okay, this is more of a fun reason, but worth mentioning. I’ve generally been much happier with the hacked versions of my products, whether it be my Tivo, Wii, or car dashboard. Smart light switches are a relatively low-risk hack, as they are inexpensive, and I’m assuming the risk is turning it into a brick, not causing an electrical fire (I’ll update the blog if I have an update on that).

Getting Started

My adventure started with the spontaneous purchase of a Gosund Smart Light Switch. Like a gazillion IoT devices sold by name brand and random manufacturers, this switch is controlled by an ESP8266. Most of these ESP8266 devices use a turnkey software solution made by Tuya, a Chinese company powering thousands of brands from Philips to complete randos.

For security and sustainability reasons, I decided I didn’t want this switch connected to my home network, and even if I wrote complex network firewall rules to limit its access, it would need to connect to the open Internet and other devices in my house to work properly.

I did some research and found Tasmota, an open source project that replaces the software on ESP8266 or ESP8285 devices, eliminating the need for Internet access and enabling functionality that make them easier to connect to controllers like Amazon’s Alexa. The older examples required disassembling the device and soldering to hack it, which is exactly not what I wanted to do. However, more recently there was an OTA (over the air) solution that didn’t require opening a device at all, and did all of the hacking over wifi… that sounded great.

Tasmota Wifi Installation

When I tinker I like to use a computer that I can reset easily so that I don’t have to worry about an odd configuration causing problems later. I have an extra Raspberry Pi that is handy for this, and installed a clean version of the Raspberry Pi Desktop to install on an extra Micro SD card.

I installed TUYA-CONVERT, which basically creates a new wifi network that and forges the DNS (how computers translate a name like to numbers that identify a server) to resolve to itself rather than the Tuya servers, so that when the device goes to get a software update from the mothership, it gets the Tasmota software installed instead – hacking complete.

Gosund Light Switch In Dangerous Setting
An example of poor judgment, however the red load wire is capped, as that is a not good wire to touch when the switch is on.

I started running the tuya-convert script on my Raspberry Pi and, rather than go through the full process of installing the switch in the wall, I found a standard PC power cable (C13) was the perfect size to hold the wires in place or allow testing on my desk. DO NOT DO THIS – I am showing you only as an example of what a person of questionable judgment might do. The switch powered up and on the tuya-convert console I could see it connecting and trying to get the new software! I love it when things just work.

But then, it didn’t work. While there was a lot of exciting communication happening between Raspberry Pi and the switch, ultimately the install failed. Looking at the logs, I was getting a message “could not establish sslpsk socket“, and found this open issue, New PSK format #483. Apparently, newer versions of the Tuya software require a secret key from the server to do a software update, and without the key (only known by Tuya), no new software will be accepted. So, damn… these newer devices can’t use the simple OTA update. Also, if you have older devices, do not configure them with the app it comes with if you plan on hacking, as that will update them from the OTA-friendly version to requiring the secret key.

Tasmota Serial Cable Installation

I realized I was too far down the rabbit hole to give up, so it was onto the disassembly and soldering option. The Tasmota site has a pretty good overview of how to do this, although I thought a no-solder solution would be possible, and tried to find the path that requires the least effort (yay laziness).

Gosund Light Switch Circuitboard
Gosund light switch SW5-V1.2 circuitboard, pen for scale. The connection points are the six dots towards the top, running down the right side (zoom in for labels).

Opening the switch required a Torx T5 screwdriver (tiny, star-shaped tool), and I happened to have one laying around from when I replaced my MacBook Pro battery. Looking at the circuit board, I realized that very tiny labels and contact points, combined with my declining eyesight, made this a challenge. I took a quick photo with my Pixel 4a and zoomed in to see what I needed… the serial connections on the side of the board (look for the tiny RX, TX, GND, and 3.3 labels… no, really, look). While soldering would be the most reliable connection, I was hoping test hook clips would do the job.

Since I was already using a Raspberry Pi, I didn’t need a USB serial adapter, as I could connect the Pi’s GPIO directly to the switch. Again, the Tasmota project has a page giving an example of connecting directly to the Pi. Whatever method you use, it is critical you connect with 3.3V, not 5V, and the higher voltage will likely fry the ESP8266. If you have a meter handy, check and double check the voltage. And, if you’re using the Raspberian OS, you may find /dev/ttyS0 is disabled… you will need to add enable_uart=0 to your /boot/config.txt file and reboot.

I connected the switch directly to the Raspberry Pi. There ware several things annoying about this, starting with each time the switch is connected to the 3.3V, it reboots the Pi. And since almost every command to the switch requires resetting its programming mode through a power cycle, that means rebooting the Pi frequently (fortunately it is a fast boot process).

Test hook clips connecting the Raspberry Pi to the Gosund switch worked surprisingly well.

The good news is, the test hook clips worked, which was a bit of a surprise. I added a connection from Pi ground to switch 00 (green wire in the photo), as that forces the switch to enter into programming mode at boot (it is okay to leave that connected during the hacking process, or you can detach it once it is in programming mode). I made sure everything was precariously balanced to add excitement and more opportunities for failure into the process. I was able to confirm that I entered programming mode and had access to the switch by esptool, a command line utility for accessing ESP82xx devices. Success! 🎉

The bad news is, other than being able to read the very basics from the switch, like the chip type, frequency, and MAC address, pretty much everything else failed. And, each successful access only worked once and then required a reboot. I was unable to upload new software to the switch. After researching a bit, the best clue I had was problems with voltage drops on homemade serial devices, and wiring directly to the Pi circuitboard seemed like it might apply. At this point I needed a drink, and went with a nice IPA.

But hey, once you’re this far down the rabbit hole, why stop? I decided to try a more traditional serial connection, using a CH340G USB to serial board.

Serial Killer Part Two

Apparently there was an issue using the Raspberry Pi directly for the serial communication as the USB to serial adapter worked perfectly. I validated the connection using esptool and then used the tasmotizer GUI, which makes it easy to backup, flash, and install new software on the switch. Many steps require rebooting the switch to proceed to the next step, but that is as simple as unplugging the USB cable and plugging it back in (even better that it isn’t triggering a reboot of the Raspberry Pi each time).

Tasmotizer and the default web interface to configure your newly-hacked switch

Once the new software is installed, there is one final reboot of the switch (don’t forget to disconnect the ground to 00 or else it boots back into programming mode). At this point the switch sets up a wifi network names tasmota[mac] where [mac] is part of the mac address. Connect to this network and point your browser to and you are able to configure your device. Set AP1 SSId and AP1 Password to your home wifi, click “save”, and a few seconds later your switch will be accessible from your home network.

I’ll provide the details of configuration in a follow-up post, but I used the Gosund SW1 Switch template following these instructions to import it, and turned on “Belkin WeMo” emulation to make the switch automatically discoverable by Alexa, without the need to install special apps on my phone or skills on Alexa. The configuration process and connecting to Alexa was incredibly easy and took less than 5 minutes.

Update January 2, 2020: I added a post on hacking the Gosund Smart Dimmer Switch (SW2) and the Youngzuth 2-in-1 Switch, each of which required a different technique.

If you’re curious about attempting this yourself, have questions about my sanity, or have other experiences hacking your smart devices, I’d love to hear from you – please leave a reply below!

Make an Antique Garage Door Opener Internet Capable

I have an early 1990’s garage door opener that does all of the things you need a garage door opener to do (it… opens the garage door). However, the remotes are the size of cinder blocks and I never have one with me when I need it, so I decided to find a way to use my phone instead. This project is part of a long history of unnecessarily connecting items in my house to the Internet.


  • A janky garage door opener, ideally the kind with wired switches attached to your garage wall
  • Some form of a server… nothing powerful. A $50 Raspberry Pi is about 50x more powerful than you need
  • A relay controller. For this project I happened to have a CanaKit UK1104 USB relay controller laying around
  • Some wire to connect from your server to the garage door opener, CAT5 is overkill and works great
  • A patient / forgiving significant other


  1. Wait for your significant other to leave the house for at least 90 minutes.
  2. Connect the relay controller to your server
  3. Grab my Garage-Door-Controller code from Github and copy it into the html directory of your server. In includes PHP and Perl scripts, the best programming languages 😜
  4. Install the Perl package Device::SerialPort. On Ubuntu / Debian: sudo apt-get install libdevice-serialport-perl
  5. Make sure the script can access the serial device… On Linux, you can add the web user www-data to the dialout group, or if you want a less secure option, use visudo and add this line: www-data ALL=(root) NOPASSWD: /var/www/html/garage/garageinterface (use the path for your server)
  6. Make sure the file garageinterface is executable, chmod a+x garageinterface
  7. Run a wire from the relay 1 on the controller to the same terminals on your garage door that the buttons on your wall are connected to (you can leave those wires in place, too… no need to make the buttons not work). On your relay, the wires should connect to “COM” and “NO” (common and normally open)
CanaKit UK1104 wired to an antique garage door opener

Opening Your Garage Door

When connected to the same network as your server, simply point your web browser to /garage and the magic begins. If you are using your phone browser, the “Add to Home Screen” option creates an icon on your phone and eliminates the menu bar, making a clean interface.

The garage door interface
It’s… pretty simple

The scripts provide a simple web interface that is responsive (it automatically adjusts to the screen where it is being rendered), so it works well on a phone web browser or whatever other web-capable device you want to use to open your garage..

There is a single “Garage Door Button” and pressing it… that’s right… it does the same thing as if you pressed the button connected to your garage door opener.

Of course you can connect the relay to whatever else you want to control… lights, refrigerators, bug zappers, sprinklers, your toaster.

Security Concerns

The HoT Garage “app” on my home screen.

If you are silly enough to follow in my path, I strongly suggest you only run this on a local home network (e.g. you must be connected to your home wifi) if you are using it on something like a garage door, partially because I didn’t consider security at all when writing the scripts, and more importantly, why in the hell would you want to open your garage door when you are not near your garage door? I know it sounds cool, but… no.

Happy Tinkering!

If you have a habit of wiring things up to teh Interwebs, I’d love to hear about your experiences… especially the ones that didn’t work out exactly as planned. Please leave a reply, below!