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GPSLoggerDevPlan

PLAN OF ACTION

  1. DONE - 2018-02-09 -- Assemble tools and learn how to flash programs onto the PIC
    • MPLAB IDE
    • PICpgm
  2. DONE - 2018-02-16 -- Learn how to enable and use the PIC's EUSART
    • Send data out
    • Read data in, then echo back out
  3. DONE - 2018-02-18 -- Add MAX242 to the circuit for true EIA RS-232 levels
  4. DONE - 2018-03-01 -- Learn how to use PIC interrupts for serial data reception
    • Answer the question: Should incoming data reception be polled, OR, interrupt driven? USE INTERRUPTS
  5. Learn how to best utilize available power configurations:
    • Low-Power mode of PIC
    • Low-Power mode of MAX242, with one receiver still enabled Controlled by PIC using output pin, one receiver still active
    • Q: How can the MAX242, upon receiving serial data, power up itself and the PIC? PIC in SLEEP MODE receives data from UART and 'wakes up'
  6. DONE - 2018-03-20 -- Learn how to interface MMC/SDcard to PIC
    • read a sector, send to serial OUT
    • write a sector (then verify by reading and echoing out)
    • Q: How can the PIC with only 384 bytes of RAM read and write a sector's-worth of data? On-the-fly? On the fly
  7. Q: Is it just as well that I use an onboard flash memory, rather than MMC/SDcard? NO - can use SD Card
    • Requires a 'dump' facility from the device (which might be nice with MMC/SDcard anyway, too)
  8. Q: decode NMEA-0183 data on-the-fly, saving pertinent bits to storate, OR just log every NMEA message?
    • determine how much processing is required of the PIC to interpret the NMEA data stream.
    • Q: is there time to parse the NMEA data, store it, and still be ready for next NMEA sentence?
  9. Confirm storage layout
    • Use a pre-formatted SDcard with a single allocated file? YES, or multiple pre-allocated files
    • Use sequential sectors with EOF markers DONE: at startup, binary search of card for first empty sector