{"id":9089,"date":"2026-01-29T11:37:59","date_gmt":"2026-01-29T19:37:59","guid":{"rendered":"https:\/\/visualgdb.com\/w\/?p=9089"},"modified":"2026-01-29T19:40:43","modified_gmt":"2026-01-30T03:40:43","slug":"refactoring-existing-code-with-ai","status":"publish","type":"post","link":"https:\/\/visualgdb.com\/tutorials\/ai\/thermostat\/01-refactoring\/","title":{"rendered":"Refactoring Existing Code with AI"},"content":{"rendered":"

This tutorial shows how to use AI edits to quickly reorganize code from existing projects to make it more structured. Using short prompts and faster models with near-instant results eliminates most of the repetitive work, while still giving you full control over the result.<\/p>\n

This is the first tutorial in the series where we are using AI to turn a third-party open-source HTTP server for Raspberry Pi Pico<\/a> into a smart thermostat. In this tutorial we will use AI to quickly move temperature-related logic into a separate struct, so we can later add automatic temperature control to it.<\/p>\n

    \n
  1. Start by cloning our fork of the HTTP server<\/a> that fixes build issues on Windows:\n
    git clone https:\/\/gitlab.com\/sysprogs-tutorials\/picow-http-example -b before_edits --recursive<\/pre>\n
    Make sure you are checking out the before_edits<\/strong> tag that does not have the AI-driven edits yet.<\/li>\n
  2. Open the project in VisualGDB and try building it. If it fails due to missing Python dependencies, edit the PYTHON_FOR_GPERF<\/strong> variable in lib\\picow-http\\CMakeLists.txt<\/a> to point to a Python installation that contains brotli<\/strong>, pyyaml<\/strong>, jinja2<\/strong> and cryptography<\/strong> packages:\"\"<\/a><\/li>\n
  3. The sample server will try to connect to an existing Wi-Fi network. You can use VisualGDB Project Properties to update the SSID and password:\"\"<\/a><\/li>\n
  4. Build the project again and press F5 to start debugging it. The server should connect to the Wi-Fi network, and opening its IP address in the browser should show the sample page:\"\"<\/a>Note that the example server only works with HTTP, not HTTPS, so you need to explicitly specify it in the browser (e.g. http:\/\/192.168.137.111\/<\/strong>).<\/li>\n
  5. We will now begin modifying the example to work as a simple thermostat. To keep the code organized, all thermostat-related variables will be contained inside the Thermostat<\/strong> struct, and all thermostat-related functions will take a pointer to it (e.g. Thermostat_SetTargetTemperature(&g_Thermostat, 123)<\/strong>).\u00a0Use the Add->New File<\/strong> command in Solution Explorer to add two files to the logic<\/strong> subdirectory:
    \nThermostatController.h<\/strong>:<\/p>\n
    #pragma once\r\nstruct ThermostatController\r\n{\r\n};\r\nextern struct ThermostatController g_Thermostat;<\/pre>\n
    ThermostatController.c:<\/strong><\/p>\n
    #include \"ThermostatController.h\"\r\nstruct ThermostatController g_Thermostat;<\/pre>\n<\/li>\n
  6. The sample project already contains code for reading the temperature value, so it would make sense to reuse it for the thermostat. If you search the code for “temperature”, you can quickly find the get_temp()<\/strong> function that recomputes the value from the temp_adc_raw<\/strong> variable:\"\"<\/a><\/li>\n
  7. Let’s move the temperature-related logic inside g_Thermostat. <\/strong>Instead of dealing with the value and the critical section directly, get_temp()<\/strong> should simply call Thermostat_GetRawValue(&g_Thermostat)<\/strong> and let the thermostat logic handle the locking and storing. Doing this by hand would require several small annoying changes:\n