Build Flash and Monitor

Build and upload

pio run -d firmware -e esp32-s3-n16r8
pio run -d firmware -e esp32-s3-n16r8 -t upload

One-liner upload and monitor:

pio run -d firmware -e esp32-s3-n16r8 -t upload && pio device monitor -d firmware -b 115200

Pin upload port when needed:

pio run -d firmware -e esp32-s3-n16r8 -t upload --upload-port /dev/ttyACM0

BOOT + RST fallback

If upload stalls at Connecting...:

1. Close any active serial monitor
2. Hold BOOT
3. Tap RST/EN
4. Release BOOT
5. Retry upload

Serial output markers

Run monitor:

pio device monitor -d firmware -b 115200

Look for:

• [wifi] connected
• [mqtt] connected
• [telemetry] published
• [event] published

Successful [mqtt] connected confirms MQTT MQTT
Message Queuing Telemetry Transport — lightweight publish/subscribe protocol used between ESP32 and AWS IoT Core. over mTLS mTLS
Mutual TLS — both client and server present certificates. ESP32 uses mTLS with AWS IoT Core over TLS 1.2. to IoT Core IoT Core
AWS IoT Core — managed MQTT broker with X.509 device authentication for ESP32 telemetry and events. .

LED behavior

Blue RGB flash indicates successful publish behavior.

• Default LED route is GPIO48
• Some board variants require PIN_NEOPIXEL=38