Nick Bild

A voice-controlled shower (????: Mellow Labs)

Voice control has found its way into just about every corner of the smart home. You can ask a speaker to dim the lights, adjust the thermostat, or start the coffee maker. But a voice-controlled shower? That's probably not high on most people's wish lists. Even so, after a viewer suggested the idea in the comments of a previous video, Tomasz from the Mellow Labs YouTube channel decided to see if it could actually be done.

Rather than redesigning the plumbing, Tomasz came up with a plan to build a removable device that could rotate the shower's diverter valve on command, switching between a handheld showerhead and an overhead rainfall showerhead. The finished project uses an ESP32-C6, an offline voice recognition module, a high-torque servo, and a handful of custom 3D-printed parts to make it happen.

At the center of the build is DFRobot's Offline Voice Recognition Sensor, which performs all speech processing locally instead of relying on cloud services. Once it recognizes a trained command, it sends a command ID over a UART connection to the ESP32-C6. The microcontroller's job is then little more than interpreting that value and moving the servo to the correct position.

To make it work, Tomasz trained the module to wake up when it heard the word "Shower," then taught it two commands: "Regular head" and "Rainfall head." After determining that the shower's diverter required approximately 180 degrees of rotation from one position to the other, the ESP32 software was designed to simply map each command to one of those servo positions.

Since the entire assembly needed to be removable, Tomasz designed a two-piece clamp that grips the shower pipe while supporting the servo. A 3D-printed servo horn wraps around the diverter handle so the motor can rotate it directly without modifying the fixture itself.

Consumer 3D printers generally cannot reproduce the tiny spline teeth found on standard RC servos, so Tomasz heated the servo's metal output shaft and pressed it into the plastic of the custom horn. The process melted an accurate spline pattern directly into the adapter, creating a snug fit that could then be secured with the servo's center screw.

After installing brass heat-set inserts and assembling everything with M3 hardware, the bracket clamped securely around the shower pipe. For the prototype, the ESP32, voice module, and breadboard remained mounted to the bathroom wall with hot glue and were powered by a USB power bank. That’s probably not the ideal solution for something that’s going to get soaked with water, but it worked well enough to prove the concept.

If for some unthinkable reason you want to voice-control your own shower, check out the video below for some tips.

voice control

artificial intelligence

microcontroller

Nick Bild

R&D, creativity, and building the next big thing you never knew you wanted are my specialties.