For common smart home applications, like controlling lightbulbs, playing music, or managing a thermostat, there are plenty of perfectly good off-the-shelf solutions available. However, when those applications become more exotic, or when they start spilling out of the home and into the surrounding property, commercial systems that are up to the task will be harder to come by. For cases such as these, it’s time to DIY.
YouTuber PricelessToolkit wanted a device that was capable of monitoring when his mailbox was opened, or when doors or windows in a shed on his property were opened. Wi-Fi signals would not work reliably at these distances, and tests with Zigbee didn’t fare any better. So with no good options available, PricelessToolkit got busy designing a custom solution to the problem…
For common smart home applications, like controlling lightbulbs, playing music, or managing a thermostat, there are plenty of perfectly good off-the-shelf solutions available. However, when those applications become more exotic, or when they start spilling out of the home and into the surrounding property, commercial systems that are up to the task will be harder to come by. For cases such as these, it’s time to DIY.
YouTuber PricelessToolkit wanted a device that was capable of monitoring when his mailbox was opened, or when doors or windows in a shed on his property were opened. Wi-Fi signals would not work reliably at these distances, and tests with Zigbee didn’t fare any better. So with no good options available, PricelessToolkit got busy designing a custom solution to the problem. It’s called PirBox, and it uses LoRa to connect a PIR sensor, reed switches, and solid-state relays to your smart home controller.
The device offers several input options (📷: PricelessToolkit)
The PirBox custom circuit board was designed around a Microchip ATtiny3216 microcontroller and an SX1262 LoRa wireless transceiver chip. A PIR sensor is included on the board, as are a pair of inputs for reed switches (both normally open and normally closed configurations are supported). There is another input for a doorbell, but you can of course use it for any button you choose. Two solid-state relays are available to remotely switch DC loads of up to 2.5 amps. The hardware is powered by three AAA batteries and is installed in a weatherproof case.
Using this hardware, you can easily monitor gates, doors, and whatever else you want at long distances. The relays also make it possible to turn electronics on and off from your home automation system, such as Home Assistant. But for integration with this system, you will also need to pick up an appropriate LoRa gateway. There are commercial options, such as the LILYGO TTGO LoRa32, or you can use PricelessToolkit’s DIY CapiBridge, which offers two-way communication.
The PCB design files, 3D design files for the case, and the firmware have all been made freely available on GitHub.