Ublox Point-Perfection:
The traditional GNSS chips provides the accuracy of upto 5-10 meters. Using the Ublox point perfection correction the accuracy can be improved to up to few centimeters. Ublox receives the data from all gnss satellites orbiting around the world, this data is used to calculate each satellite clock errors, orbits signal biases and atmospheric delays caused by the ionosphere and troposphere the net result enables the most reliable available and accurate gnss correction data service to the end user. These binary packets are published over MQTT following the standard SPARTN protocol.
Our application subscribed to the ublox MQTT service to receive these binary packets. These will be further forwarded to the GNss chip over UART. The chip does the correction using these binary packets and there by improving the accuracy to centimeters within few seconds.
Work Highlights
- Designed and implemented full product architecture on FreeRTOS with several state-machines to deliver non-blocking, real-time application.
- Cellular connectivity using the 4G modem.
- Quectel : M95, BG95, EG91x
- Implemented following IOT features
- MQTT data ingest
- Remote Turn off commands
- Implement the point perfection on Ublox GPS servers with Binary packets received over ublox Mqtt.
- U-Blox ZED-F9P-01B
- Implemented circular buffers for offline temporary storage
- Implemented power saving features to improve battery life.
- Supported cloud team setup and integrate device features on Custom cloud
- Supported on-field teams to test and refine product
Hardware
- STM32F413RGT6
- Quectel : EG91x 4G modem
- U-Blox ZED-F9P-01B GPS module
Tools
- Built a custom NodeJS tool for
- Updating the bootloader and application to STM32
- Assign the unique serial numbers for tracking
- STM32 Cube