I recently embarked on a project to enhance the security of my garden using a Shelly 1 in 12V mode. The goal was to create a simple yet effective system that would deactivate a secondary bell at night, preventing disturbances from unwanted visitors. While the concept was straightforward, the execution required some careful planning and troubleshooting.
Initially, I considered the lack of internet connectivity at the site. The setup involves using a mobile hotspot for initial configuration, followed by relying on the Shelly 1 to operate independently. This meant addressing concerns about time synchronization without NTP. After some research, I found that the Shelly 1’s internal clock could handle minor discrepancies, but I implemented a script to perform a daily time backup to minimize drift. This solution seems to be working well so far.
Another challenge was the power supply. The existing transformer provided 8V AC, which needed to be rectified to power the Shelly 1. I created a simple circuit with a bridge rectifier and a capacitor to stabilize the voltage. Testing confirmed that the Shelly 1’s power consumption was within acceptable limits, and the relay operated reliably in the Normally Closed configuration. I also explored the idea of using an external 5V relay as a backup, but the current setup has proven sufficient.
For configuration, I decided against using the Shelly app and opted for Tasmota firmware, which provided more flexibility and customization options. Additionally, I looked into adding an RTC module for more precise timekeeping, though this remains a future enhancement.
Overall, the project has been a rewarding experience, showcasing the versatility of the Shelly 1 even in low-power, offline environments. It’s a testament to how simple yet effective solutions can be achieved with the right mix of hardware and software tweaks.