The speaker discusses their experience with reverse engineering a solar roof panel's data logger. They initially bought the solar roof with an optional data logging component and discovered there was a Raspberry Pi connected to it. The speaker shares insights into the functionality of the data logger, such as data logging to an SD card, relay controls, and a built-in UPS. They also explore the web interface, APIs, and bugs they encountered. The speaker then goes on to discuss their process of investigating the binary files and using Radare2 to analyze the code. They identify the Modbus protocol being used and successfully map the discrete inputs to the flags. Finally, they mention re-implementing the software using Modbus and fixing some bugs they discovered. The speaker shares their source code and ends with a discussion of the PCB layout of the solar roof panel's data logger.