I have obtained several Oto Lawn smart sprinklers. Unfortunatelly one unit failed and stopped responding. I contacted Oto support, they provided troubleshooting steps. But that did not help. So, they suggested to send me another device for free and discard the failed one.

But I decided to disassemple the sprinkler and give its hardware a second life by replacing original electronic board with a Raspberry Pi Zero and write my own program to drive the device.

For now the work is in progress.