ESP32 Real Hardware Flash + WiFi

Overview

Flash firmware to a physical ESP32 over USB and verify it boots + connects WiFi. Works alongside [wokwi-mcp-testing] (sim) — this skill is for the real board.

When to Use

• First flash of a new ESP32 (PlatformIO pio run -t upload)
• Debug why upload fails to open the serial port
• Set up WiFi on real hardware (home SSID, static vs DHCP)
• Verify boot: WiFi connect + IP + web server start

Key Rule: Bash tool cannot open serial O_RDWR on macOS

Claude's Bash tool (even with sandbox disabled) gets Operation not permitted (EPERM) opening /dev/cu.* with O_RDWR — esptool/pyserial need O_RDWR, so uploads fail with "Could not open /dev/cu.usbserial-XXXX, the port doesn't exist" (esptool masks EPERM). Read-only opens (O_RDONLY, e.g. dd) succeed.

Fix: give the user the commands to run in their own terminal. Do not keep retrying from Bash.