I require a GPS logger with Bluetooth for a pet tracking project. The GPS logger will be as small as possible (guideline 13x20mm) and have a Bluetooth download capability and a mems accelerometer (LSM9DS0 - [url removed, login to view] ) for motion/inertia detection.
The GPS chipset used must be best-n class with approx. –167 dBm navigation sensitivity and an on-board passive chip GPS antenna (for example: [url removed, login to view] ) or a UFL connector to connect an active patch antenna similar to this: [url removed, login to view]
The designer can provide options for the Bluetooth SOC but sourcing SI Labs/CSR/Nordic Semi/Ti parts are preferred.
The Logging times of GPS positions must be configurable. Such configuration must include Logging on accelerometer motion or stopped. In motion and stopped logging frequency must also be configurable so that in motion every X seconds and stopped every Y seconds. Motion stopped will be defined as NO movement for Z seconds.
The GPS logs will be stored on FLASH memory of at least 1GBit and will be encrypted using AES256 encryption. The encryption Keys must be configurable by the user.
What will be logged?
Time, Date, Satellites in View, Lat, Long, Time since Last Valid Fix
In addition there will be a header to indicate the log is part of the logging configuration ‘C’ or triggered from an external pin 1 event ‘T1’ or external pin 2 event ‘T2’ (See Additional I/O) of Interrupt pins 1 or 2 from the LSM9DSO A1/A2
Time, Date, Satellites in View, Lat, Long, Time since Last Valid Fix, C/T1/T2/A1/A2, Accelerometer data, Gyro Data, Magnetometer data
The logger will have an additional FOUR I/O pins accessible so that other user functionality can be defined. For example one case usage is an external trigger (PIN goes LOW from an external source) and the logger will instantly LOG that GPS position and time etc. two of these pins will be connected to the INT1/2 outputs pins of the LSM9DS0 and two will be user accessible for pulling logic LOW.
The GPS logs will be downloaded to an android application or PC application via Bluetooth. This Bluetooth link must be secure and the Bluetooth PIN code of the logger must be unique to that logger. This Pin code must be set in firmware and an interface should be presented so that a pin code can be defined and set. Once paired the AES crypto keys, file downloads and device configuration will be set by an application. The bluetooth chipset used will be a Class 2 device with an on board chip antenna. To save power, the bluetooth chipset will only poll for its paired device every 60 seconds and be either sleeping or turned off otherwise. Once connected the bluetooth link will remain active until the pairing drops for 30 seconds.
The sensitivity of the accelerometer must also be configurable by the user. It is envisaged that the device will use a ST Microelectronics LSM9DS0 iNEMO inertial module where an interrupt pin on the module will be configured to flag movement to the logic element of the logging control.
The logger will be powered from a battery of 3.6V. This battery will likely be a Li-Ion. Power supply limits will be [url removed, login to view] through 5V DC. The device will not have to charge this battery.
1. Design documentation (BOM/schematics (EAGLE), functionality system design, board layout/gerbers)
2. Sample Boards x 5 for testing
3. Firmware (source code and documented)
4. Either android application or PC (WIN10) application for download and configuration with source code (documented)