Wiring

Connect the '+' lead of the piezo to GPIO 4 (D2 on WeMos D1 Mini) and '-' lead to Ground. I chose GPIO 4 because I installed the long leads with the headers on the WeMos D1 Mini. The spacing from ground was perfect to just plug the buzzer in direct between G & D2.

Build Firmware

I use PlatformIO to build this. http://platformio.org/

• Install PlatformIO and let it update itself on first startup
• Once updated and restarted, clone the "mobile-rr" project to a folder and open the project in PlatformIO
• Next build the firmware by clicking the checkmark icon on the toolbar

Upload Firmware and SPIFFS data

After your firmware build is successful you can upload it by clicking the arrow under the checkmark in the PlatformIO toolbar.

You can add/edit the files in the "www" folder to your liking. (Files in the "www" folder will be cloned and gzipped to the "data" folder when building.) Then follow the instructions below to build and upload the SPIFFS file system image to your ESP8266.

Note: Anytime you make changes to the firmware or the data you can rebuild and upload either without the need to install the other again. They reside in different areas of the flash memory.

To save more space you can gzip the HTML, Javascript and CSS files in the data directory. Just make sure they have a .gz extension and they will be served up properly.