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LoRa Basics Modem and LoRa Edge documentation
Scenario - GNSS Autonomous Scan¶
Introduction¶
One of the key features of the LoRa Edge™ Platform is the ability to scan GNSS signals and provide the measurements to a LoRa Cloud™ Services to determine the location of a device. Here, we review the requirements for completing an autonomous GNSS scan by the LR111x chip and for returning it to the device application.
Prerequisites/Dependencies¶
Common:
Must have an SPI connection in order to exchange information between the end-device application and the LR111x chip.
Prerequisites for LoRa Basics™ Modem:
Not applicable
Prerequisites for LoRa Basics™ Modem-E:
No additional requirements
Prerequisites for a Transceiver:
No additional requirements
Step-by-Step Procedure¶
LoRa Basics Modem-E¶
Optionally, specify the constellations to scan. (By default both GPS & Beidou are scanned.)
Through the SPI interface, the host MCU calls the GNSS autonomous scan command (
0x0430
).Note
Scan options include: Effort Mode, ResultMask, and NbSvMax.
Depending on the effort level, scans may take 2-10 seconds per constellation.
When the scan is complete, the EVENT signal on the Lora Basics Modem-E is set high.
The host MCU calls
GetEventsize
(command0x0633
) andGetEvent
(command0x0600
).The LoRa Basics Modem-E returns the assisted GNSS scan results.
The LoRa Basics Modem-E sets the EVENT signal low.
Note
After a successful scan when a precise timestamp is not available, it is important that the data is transmitted to the application server for processing as soon as possible, with the associated capture time of t=0.
Transceiver¶
Optionally, specify the constellations to scan. (By default both GPS & Beidou are scanned.)
Through the SPI interface, the device application calls the
GNSSAutonomousScan
command (0x0409
).Note
Scan options include: Effort Mode, ResultMask, and NbSvMax.
Depending on the effort level, scans may take 2-10 seconds per constellation.
If
GNSSDone
is enabled, the IRQ signal on the LR111x chip is set high.The device application calls
GnssGetResultSize
(command0x040C
) andGnssReadResults
(command0x040D
).The LR111x chip sets the BUSY signal low .
The LR111x chip returns the assisted GNSS scan results.
If enabled, the LR111x chip sets the IRQ signal low.
Note
After a successful scan when a precise timestamp is not available, it is important that the data is transmitted to the application server for processing as soon as possible, with the associated capture time of t=0.
Used By¶
Device application, LR111x chip
Troubleshooting¶
If the GNSS Event starts with 0x00
the payload is NOT to be sent to the application server for processing. This GNSS event message is called GNSS Events for the Host MCU in the Reference Manual and does not contain a NAV message. Check the second byte and refer to the LR111x user manual for its significance.
LoRa Basics Modem and LoRa Edge documentation
Table of Contents
- Overview - LoRa Edge™ Asset Management Platform
- Use Case - Basic Asset Tracking
- Use Case - IR Image Upload on Detected Motion
- Scenario - GNSS Assisted Scan
- Scenario - GNSS Autonomous Scan
- Scenario - LoRa Basics™ Wi-Fi Passive Scan
- Scenario - GNSS Scan with ROSE
- Scenario - Wi-Fi Scan with ROSE
- Scenario - LoRa Cloud™ Join Server
- Scenario - Claiming a Device
- Scenario - Unclaiming a Device
- Scenario - Modem-E Initialization
- Scenario - LoRa Basics™ Almanac Update
- Scenario - User Loaded Almanac Update
- Scenario - Intermittent Network
- Component - Clock Synchronization
- Component - Large File Upload
- Component - Reliable Octet Stream Encoding
- Cryptographic Engine
- Glossary
ADDITIONAL RESOURCES - VIDEOS