I know I haven't finished off my desk clock project just yet, But I've been requested to design a new GPS logging device for my sisters Beagle Club,
The basic idea is that a sent is placed with a guy that forms a path, the GPS logger is taken along also.
They then attach the device to a beagle (using some kind of vest, I think). And let them follow the scent.
Post event they extract the GPS data from the logger and overlay both tracks in google earth.
They have one unit that has been working well for them, developed by a previous club member.
It consists of off the shelf components from Sparkfun. With a total BOM just over $150
- Logomatic V2 (https://www.sparkfun.com/products/12772)
- GPS (https://www.sparkfun.com/products/8975)
- 128mb uSD
- Old Cell phone battery (Li-ion) (~700mAh judging from physical size)
All of these are connected together and fit into an off the shelf jiffy box.
They would like 5 more made, which would perform identical/similar function
Design goals:
- Lower cost (< $50AUD per unit, making 5 units)
- Externally operates identically to the old version
- USB MSC
- Logs start when unit powered on via toggle switch
- new log created when button pressed
- All additional tools stored on SD card (GPS utilities, past logs)
- Long battery life, unit should operate for > 10Hours
- Physically the same size or smaller
- (if time allows, a simple PC tool to to reset the device into DFU mode, and update the firmware)
I'm planning to source a more slimline case. once I have that I will begin PCB design.
I have drawn some quick System level schematics
The hardware is pretty straight forward
Same with the software, I have already played with the MSP430 USB MSC examples, and am familiar with FATFS. I should be able to glue in some UART code to get it all to work.
The device will operate under two modes depending on if it's connected to USB or not.
Hopefully someone will find this mildly interesting as I work through it.