piNail ESP32-C3 (Single-Nail)

ESP32-C3 firmware for a single-nail piNail controller.

What changed vs piNail2

• Single nail only.
• Loop timing is fixed for responsiveness (1800ms cycle, 200ms tick).
• Loop timing controls are intentionally not exposed in API/UI.
• Wi-Fi onboarding uses captive portal (piNail-Setup / pinailsetup).

Hardware target

• Board: ESP32-C3 DevKitM-1 class board.
• Thermocouple ADC: MAX6675 (SPI-like bitbang).
• Relay output: active HIGH relay module.

GPIO mapping

• Relay: GPIO2
• MAX6675 SCK: GPIO4
• MAX6675 CS: GPIO5
• MAX6675 SO: GPIO6

API compatibility

Implemented endpoints:

• GET /api/status
• GET /api/history
• POST /api/power
• POST /api/setpoint
• POST /api/pid
• POST /api/pid/reset
• POST /api/safety/reset
• GET /api/heartbeat

Not implemented in this firmware:

• Scheduler and dual-nail routing.
• Autotune endpoints.
• Loop timing reconfiguration endpoint.

Build and flash

pio run -t upload --upload-port /dev/ttyACM0
pio device monitor -b 115200 --port /dev/ttyACM0