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Part 1 by Richard palmer HOME ASSISTANT R P with a aspberry i There are many situations around the home and on the workbench where remote sensing and control can improve our lives. T his short series will explore the world of home automation and create the core of a system that interfaces with a broad range of commercial smart home devices, plus hundreds of DIY sensors and remote-control interfaces. That will include everything from sprinklers to music systems, pet tags to air conditioners. Home automation has matured to the point where do-it-yourself installations can be achieved without needing to write code. Readily available sensors and controls can be wirelessly connected to a central hub and added to the system with just a little configuration information. This month, we will review community-­supported home automation platforms. We’ll also discuss our simple project (in this issue) that can connect sensing and control devices to a central home automation hub using a WiFi network. A follow-up article next month will have information on more advanced matters, such as remote access, customised dashboards and cameras. Smart homes & IoT IoT (the Internet of Things) connects the physical and virtual worlds using sensors and controls connected to monitoring and automation software via communication networks. Home automation is a subset of IoT focused on the domestic environment. 48 Silicon Chip Home automation begins with sensing something in the environment, such as time, temperature, light intensity, the presence of smoke, or movement. A set of rules is applied to automate actions, such as switching a light on or off, or sending a notification based on sensed changes. A typical home automation system includes an in-home server (the ‘hub’), and a range of ‘satellite’ devices distributed around the property, communicating using some form of wireless link. That link could be a local WiFi network, Bluetooth or a Zigbee mesh. The hub is either a stand-alone device, or connects to a cloud-based platform which enables remote access – see Fig.1. Dr David Maddison’s review of home automation in the January 2024 edition of Silicon Chip (siliconchip. au/Article/16082) describes many of the available technologies and protocols used. There are a multitude of commercially available devices that can directly interact with home automation services. A quick internet search turned up eleven pages of smart home products at Officeworks and 740 products at JB Hi-Fi, covering lighting, gardens, security and even smart pet-tech. Similar searches via AliExpress and eBay each returned more than fifty pages of results. Where devices are not designed to be directly controlled by such a system, automated control can often be implemented by switching their power on and off, or mimicking an existing control capability, such as an infrared (IR) remote. For devices with no remote control capabilities, there are Fig.1: the HomeAssistant ecosystem comprises a local hub with satellites that host sensors & controls. Satellites may be microcontroller-based, using ESPHome, or be fully integrated units such as IP cameras. Communication between elements commonly uses WiFi, Bluetooth or Zigbee. Remote access to the system can be provided by a VPN or cloud service. Australia's electronics magazine siliconchip.com.au There are excellent and easy-to-use commercial integration platforms such as Google Assistant, Amazon Alexa, Apple HomeKit, Philips Hue and Samsung SmartThings. Each has its pros and cons. However, these platforms are largely devoid of features that support DIY. Almost all require a commercial in-home hub and an online account. Mix-and-match integration of various vendor’s ‘ecospheres’ into one master platform can be a frustrating and sometimes-unattainable goal. Fortunately, there are several groups of enthusiasts that have created opensource home automation ecosystems that can integrate with a range of commercial hardware and also support DIY applications. Two enthusiast-­ friendly platforms stood out as I began researching this series: openHAB and HomeAssistant. They both offer a fully featured hub, integrations with a wide range of DIY and commercial home automation products, remote access and integrated cloud services. Both host their hubs on the Raspberry Pi platform using customised operating systems. They both offer voice control via integration with smart home assistants such as Google Assistant, Siri or Alexa. For DIY projects, HomeAssistant (HA) stood out. From the hub’s browser interface, you can configure and manage remote sensors and controllers based on WiFi-capable microcontrollers such as the Raspberry Pi Pico W and Espressif Systems wireless microcontrollers (eg, the ESP8266 & ESP32) using HA’s ESPHome firmware. More than a hundred sensors and control interfaces are pre-­ integrated. While HomeAssistant’s cloud service costs around $10/month, remote access can be configured at no cost using one of several free VPN services. openHAB also has a very wide range of integrations with commercial home automation devices; however, integrating DIY projects is more Fig.2: the HomeAssistant platform has three layers: a basic Linux operating system, a Supervisor layer and the HA Core. Source: https://developers.homeassistant.io/docs/architecture_index The HomeAssistant Overview dashboard with the ESPHome satellite and a USB webcam installed. » Fully-featured DIY home automation system using a Raspberry Pi » Integrates with a wide range of commercial & DIY equipment » Remote access via smartphone, tablet or computer » Broad open-source community support ‘fingerbots’ that can press a button on command! Choosing a platform siliconchip.com.au Australia's electronics magazine complex. Its cloud platform, myopenHAB, is free. While openHAB’s free cloud service was very tempting, we selected HomeAssistant for this series based on its flexible DIY device capabilities. Installation on a Raspberry Pi 3B, 4 or 5 is straightforward, or it comes pre-installed on HA’s Yellow or Green platforms. HomeAssistant HomeAssistant has three layers: a basic Linux operating system, the HA Core that interacts with users, devices and services and the Supervisor, which orchestrates the various HA components and manages backups and updates – see Fig.2. Home Assistant’s language can be confusing at first. A few key definitions may be helpful: • An ‘entity’ is the basic building block of home automation. It represents a single sensor, control element or function. Entities have ‘states’, which may be binary or a range of values. • A ‘device’ may host a single entity, such as a switch or a light sensor, or several entities, such as temperature, pressure and humidity sensors. • An ‘area’ is a logical grouping of entities and devices, often representing a geographic location, such as a kitchen. Areas can be assigned to ‘floors’. • An ‘integration’ is the software that connects HomeAssistant to a compatible device, such as an ESPHome September 2025  49 Another practical application While writing this article, a local community radio station needed to improve the monitoring and control of the equipment at its transmitter site from the studios, or remotely using the engineering team’s laptops or phones. The station’s two transmitters, uninterruptible power supply (UPS), studio-­ transmitter link and backup program links have a range of digital and analog inputs and outputs for monitoring and control. HomeAssistant and ESPHome seemed a good solution to their problem. Pico-based satellite hardware like that described in the accompanying project article was used for the thirty-odd digital and analog values to be monitored and drive relay and opto-isolated outputs. It only took a few hours to integrate the hardware into ESPHome and create the required sensors and controls in HomeAssistant. No custom code was required, saving weeks of programming and improving reliability. satellite or a webcam, or another home automation or service platform such as email or the HomeAssistant Cloud. • ‘Automations’ are sets of repeatable actions that can run automatically. They comprise ‘trigger’ events, tests for ‘conditions’ on those events and resulting ‘actions’. You can find a more detailed discussion of these concepts at siliconchip. au/link/abr3 The Home Assistant hub We chose to create our own hub using a Raspberry Pi. Any Raspberry Pi, from the Model 3B onwards, will do. All that is required besides the Pi is a 32GB Class A2 microSD card for the custom HAOS operating system. An existing Raspbian SD card can be overwritten with the new OS. Details of the requirements and options are available on the HomeAssistant website (siliconchip.au/ link/ac5w). While many home automation needs can be satisfied with off-theshelf commercial components, there are still situations where it is more practical and less expensive to create a DIY solution. There are also situations where a compatible remote control device isn’t available commercially, but the communication protocol is well-­ documented. TVs and air conditioners are a case in point. To assist with these needs, we have developed a small PCB that can connect to a wide range of digital, analog and I2C sensors, as well as controlling devices via an IR signal or relay. It is Screen 1: when preparing the SD card, select Home Assistant OS in the Raspberry Pi Imager app. 50 Silicon Chip Australia's electronics magazine This fingerbot can press a button on any device as a simple remote control. presented as a separate project in this issue, starting on page 54. Setting up HomeAssistant For the purposes of this tutorial, we will use a Raspberry Pi Model 5 as the hub. However, the process is similar for other platforms. Detailed instructions are available at siliconchip.au/ link/ac5w When procuring a case for the Raspberry Pi, avoid those made entirely of metal as they tend to reduce the WiFi range significantly. The official redand-white plastic case or a clear acrylic case are solid choices. The active cooler kit is also a good investment and fits neatly into the acrylic case. The HomeAssistant and ESPHome communities are very active, producing updates several times a month. For this reason, some of the instructions below may be out of date by the time this series is in print. Don’t despair if this happens; the documentation is kept up to date and help is available via the very responsive HomeAssistant user community (https://community. home-assistant.io). If you don’t want to build your own hub, the pre-configured HomeAssistant Green hub is readily available for around the same price as a well-­ configured Raspberry Pi 5 and case. Preparing the Pi is straightforward. If it came in kit form, just fit the motherboard into its case and mount the cooler’s heatsink. The fan cable goes into the connector behind the outside-­ edge USB connectors. There is no need to load or configure the Raspbian OS, as it will be replaced by HA’s HAOS operating system. Install and run Raspberry Pi’s Imager software on a Windows, Mac or Linux PC – see Screen 1. Select your siliconchip.com.au Raspberry Pi board from the list in the first box, then choose the required operating system in the second box, by selecting “Other specific-purpose OS”, then “Home Assistants and Home Automation”, then “Home Assistant” and the blue-logo version from the drop-down menus. Plug in an SD card adaptor with the microSD card installed (or, if your computer/monitor has an integrated SD card socket, use that). Select that card in the final Imager box. Click NEXT, and the card will be programmed over several minutes after an erasure warning box is displayed. Installing the OS There is no need for a screen, keyboard and mouse for the Pi as the installation is ‘headless’. Wired Ethernet is mandatory for the initial installation process, but it can be replaced by WiFi once HA is configured. Insert the SD card into the Pi and an Ethernet cable between the Pi and your WiFi router. Connect the power adaptor and press the power button on the Pi if it remains red after connection. Wait for 4-5 minutes for HAOS to initialise. The green power LED will flash intermittently during this time. The final configuration steps are completed via a browser on your PC; enter “http://homeassistant. local:8123/” in the URL bar. Refresh the URL regularly until the Home­ Assistant welcome page loads. Click on the “Create my smart home” button. The Name field is used for display, while the Username is used for logging in. They can be the same name. Add your location, which will be used for the weather displays and proximity mapping of any devices you choose to track. Select what information you wish to share with HomeAssistant’s developers. A screen of compatible devices that HomeAssistant has located on your network completes the basic installation process. The HomeAssistant Overview screen should then appear, as shown in Screen 2. Click on the Settings menu item and then Network. Under “Configure network interfaces”, click on WLAN0 and SEARCH NETWORKS. Select your WiFi network from the list, choose the appropriate security scheme, and enter your WiFi password. Click the SAVE button at the bottom of the block, not the one at the bottom of the page. siliconchip.com.au HomeAssistant-compatible cameras Several types of cameras can be added to HomeAssistant. The simplest is a USB webcam connected directly to the hub. Most commercial USB webcams should be compatible. If a remote camera is required, ESP32-based ESP-CAMs are available at very low cost and with acceptable picture quality. A USB-CAM with the standard OV2640 camera, including the USB adaptor board, costs less than $10 on AliExpress (eg, AliExpress 1005006501528278). While the OV5640 version provides a higher resolution image, plus autofocus on models with the silver lens surround, I do not recommend it. The one we tested had marginal low-light performance and tended to overheat, reaching temperatures of 70°C within a few minutes. A heatsink attached to the back of the sensor reduced the temperature to 40°C. Commercial WiFi cameras offer more advanced features such as pan and tilt, automatic IR illumination at low light levels, motion tracking and substantially better images. However, they are the most difficult to integrate due to a wide variety of firmware platforms being used. Of the WiFi cameras I tested, those using the V380 or V380 Pro configuration apps and marked ONVIF compliant in their specifications were the most likely to be compatible. We’ll have more on using cameras with HomeAssistant in the follow-up article next month. This $10 USB webcam produced very acceptable images. Screen 2: the Overview dashboard after the system has been initialised. The auto-discovery process located a Google home device; local weather is displayed by default. Parts List – Home Assistant 1 Raspberry Pi Model 3B or greater, with at least 4GB of RAM [Core Electronics CE09785] 1 Power supply for the Raspberry Pi [Core Electronics CE09787] 1 non-metallic case [Core Electronics WS-26089 or CE09789] 1 active cooler kit for the Raspberry Pi [Core Electronics CE09791] 1 32GB Class A2 microSD card 1 USB microSD card reader/writer (if your computer doesn’t have one) 1 Ethernet cable (for installation) Australia's electronics magazine September 2025  51 Left: a $10 ESP32-CAM with an OV2640 sensor. Right: a $50 WiFi camera with pan and tilt functions and IR-illuminated night vision. ONVIF compliance is essential for HA compatibility. Screen 3: HomeAssistant automatically scans the network for compatible devices. Now that your WiFi credentials have been entered, the unit no longer requires a wired connection. The username and password you set may also be used for smartphone, tablet and remote browser access. It is a good idea to use credentials without full administrator privileges whenever possible to reduce the possibility of accidental misconfiguration, and to increase remote access security. The basic installation is now complete, and you can start configuring your smart home. Before adding any new devices, it is useful to clean up the devices that have been auto-­ discovered. Select Settings near the bottom of the left-hand menu and click on Devices & services. A screen of discovered devices will appear, like in Screen 3. Devices like wireless-­capable printers and set-top boxes will be included. Click IGNORE on all except the iBeacon Tracker and perhaps a printer. They will clutter up the screen and can be easily re-discovered later. Further down the screen is a list of configured services (see Screen 4). There are some generic services, such as Bluetooth and the Home Assistant Supervisor, as well as some applications like a live-streamed radio channel browser and a weather service from the Norwegian Meteorological Institute. I clicked on “Shopping list”, then the three dots at the side of the “Integration entries” panel and then Disable to hide that service. The sidebar menu Screen 4: some services are enabled by default. Screen 5: the simplified HA menu after hiding some items. 52 Silicon Chip Australia's electronics magazine The sidebar menu has some items you may rarely use. To customise what’s displayed, click on your username at the bottom of the sidebar. Scroll down to the “Browser settings” block and click EDIT to change the order and hide items from the sidebar. Click on the X next to the items you don’t want to appear. The order can be changed by sliding the items to your desired location. Click DONE at the top of the main menu bar when you are finished. Initially, I hid all the optional items other than the Overview dashboard and the Logbook – see Screen 5. The “ESPHome” add-on will be needed to add the satellite device that’s described in the separate project article in this issue (it won’t hurt to add it regardless). Go to Settings siliconchip.com.au Screen 6: configuring the ESPHome Device Builder. Screen 7: a custom HomeAssistant dashboard showing the satellite’s sensors and controls, an IP camera’s image and a thermostat automation. The spikes in the temperature reading are from a finger being placed on the sensor. The thermostat temperature was raised during the second spike. then Add-ons, click on the ADD-ON STORE button at the bottom right, search for “ESPHome”. Select it and click the INSTALL link at the bottom of the tile, and then START once the installation is complete. Before exiting the installation menu, enable the “Show in sidebar” and “Watchdog” options – see Screen 6. ESPHome Builder should now appear in the left sidebar menu. Select it. Click on the SECRETS button at the top right-hand corner of the ESPHome tab. The edit window should contain something like the following: siliconchip.com.au ## secrets.yaml wifi_ssid: “your wifi ssid” wifi_password: “your wifi password” Fill in your network credentials and save them. This will allow new ESPHome devices to be automatically configured for your network. Click on the X next to the file name to close the edit window. Conclusion A separate project in this issue Australia's electronics magazine covers the construction of a satellite board based on a Pico W. Among other things, it supports temperature, humidity and motion sensors and an OLED display. That article will describe how to use it to create a simple thermostat, demonstrating HomeAssistant’s automation capabilities. Next month, in a follow-up article, we’ll add some more advanced features such as custom dashboards, remote access from a mobile phone or tablet, IR remote control, notifications SC and a camera or cameras. September 2025  53