MySQL Connector/Arduino
Fun demos; do not put DB credentials and 3306 on microcontrollers in production.
Connector/Arduino can INSERT sensor rows straight into MySQL. Good teaching toy.
Problems in production
- Credentials in firmware
- No pooling discipline
- Database exposed to a device network
- Weak TLS story on small MCUs of that era
Prefer
device → MQTT/HTTP ingest → validated service → MySQL/MariaDBLeast-privilege writer role. Protocol designed for devices. Database behind an application boundary.