LAN Tester

Commercial network testers are either €15 toys that beep optimistically or €1500 bricks with a subscription. So I built my own: an ESP32-S3 with a W5500 Ethernet module and a 1.77" LCD, in a package you can throw into a toolbag.

Plug the RJ45 in and the screen instantly shows IP, subnet and gateway via DHCP; unplug and replug events are detected live. That's exactly what you need for mass-testing switch ports and VLAN assignments, where dragging a laptop to every socket is a workout, not a workflow.

On the roadmap: ICMP/UDP/TCP ping tests, MicroSD config profiles, rotary-dial menu navigation, a WiFi spectrum analyzer, and LiPo battery power with a TP4056 charger — because the best tools are the ones that fit in a jacket pocket and answer questions before you reach the switch room.