A maker named John built a remote-controlled beach cart using an e-bike cargo rack, a plywood base, an ESP32, and two independently driven rear wheels for differential steering. No commercial product. No steering servo. Just a salvaged rack and a smartphone app controlling the whole thing over Wi-Fi.
The build includes a time-of-flight obstacle sensor that halts the motors on contact, a relay-controlled start button for safe power-up, and running lights for night use. Differential drive keeps the mechanical complexity low while still allowing full maneuverability across sand. The ESP32 ties every subsystem together in a single, compact controller.
The robot is not autonomous yet, and John operates it on the Great Lakes where tides are irrelevant, which makes reliable, human-piloted hauling the actual priority. Read the full piece for the wiring layout and to see how the plywood interface plate is mounted to the cargo rack, the structural solution is simpler than you expect and worth stealing.
[READ ORIGINAL →]