SparkFun RTK Torch is working great once you use FLEX RTCM/NTRIP Corrections, or RTK2go.com
Arduino: How do I connect an accelerometer (GY-521) to a SparkFun Thing Dev (ESP8266)?
We Put OpenCV on a Microcontroller and It Actually Works
Product Showcase: SparkFun Qwiic Fingerprint Sensor
How to Set Up High-Precision GNSS on a Raspberry Pi (Step-by-Step Guide)