2010 Design Notes:

Froglogger V Design Notes
June 1, 2010
Link to old Design Notes. There is a gap between mid 2009 and now (June2010 ) because of a trojan virus that destroyed files on my local PC and files on my web server.

___________________
Email from Gene to Phil on 5/31/2010 to get things up-to-date. Additional notes added Jun2 in red.

I’m reading all our emails back to middle of last year to refresh my mem.

What FL hardware do you have now.  Is it up-to-date  or do you need me to send something?  Of course when I have one ready for a new recorder I’ll provide one.

Microchip has newer USB chips out now with their “nano-watt” technology for ultra low power but our current chip(s) draw many times less power than the recorder(s) so no need to change now. 18F46J50

I can’t  remember . .  . did we plan to include some kind of DS1307 routine in the main program so we don’t have to use a special chip to start the 1307??? In our conversation via telephone Jun1 we agreed we wouldn't worry about doing that now because we're almost out of program memory and it's not a very significant issue anyway. For testing 1307 initialization on your end you can pull the 1307 out of the socket causing it to lose its backup battery power thus erasing its initialzation data.

See p. 163 of 18F4550 data sheet.   It shows internal pull-up resistors “if” they’re enabled.  Do we have them enabled?  Or should I add some external pull-ups to the pcb. (don’t want any cmos inputs floating.) I don't have any indication down here that it's a problem.

If sometime in future we can add “on-board programming” of the 18f4550 we can re-layout the pcb for all surface-mount components and have an assy house put them together for us. I also want to add a SD card interface so we can sample temp, humidity, rain, sun-light……etc…  These things would use the latest digital sensors that connect to a serial interface (share it with the RTC or display) and all the software would have to do is read and store along with the date/time. The 18F46J50 has built in Real-time Clock/Calendar.

_______________