No erase DATA EEPROM during programming

[SUNFLOWER]

Every time I program my DATA EEPROM gets erased. (WRITE AND READ are working great on the 18F4620). I used meProg from melabs and tried Options/More Options/Erase/(uncheck)Data and Options/More Options/Program/(uncheck)Data and Options/More Options/Blank Check/(uncheck)Data, however DATA is still erased. I do not want DATA Protection, just preservation. Searching this forum produced nothing that solved this problem with others years ago, so if anybody knows what to do...

Thanks.

[Darrel Taylor]

With a normal "Bulk Erase" the chip itself erases everything no matter what the options are set to.

Go to Options > More Options and select "Low Voltage Erase" which has the programmer erase things seperately one row at a time. Then unchecking the Program > Data should preserve your existing data.

It takes much longer to erase the chip that way.

[SUNFLOWER]

Thanks Darrel and meLabs, that worked. ~ The embedded solar tracking data is now preserved for new programs.

[Dave]

SUNFLOWER, I was just wondering? What kind of solar tracking data are you storing? I too have designed a 2 axis tracker for my three 1200 watt arrays about 3 years ago and I store the azmuth, elevation, up, down, east, and west sensor levels.

Dave Purola,
N8NTA

[SUNFLOWER]

Hi, Dave, we are tracking a solar dish with closed loop eyes +/- 0.004 degrees and are using Memsic accelerometers for position feedback. The recent MEMS sensor altitude and azimuth (plus time) data are stored for tracking error detection (for ground torching fire safety) and for dish approximate open loop tracking during cloudy weather. If the data are not recent because the solar declination has changed then our solar position algorithm takes over command of safety protocols. Basic Stamp was too expensive for global technical transfer so we are migrating over to PIC.

http://www.harbornet.com/sunflower/pvdish.html

[Dave]

SUNFLOWER, I just spent my lunch lour looking over the data you linked to. It really is quite interesting.. Keep up the great work....

Dave Purola,
N8NTA

[SUNFLOWER]

Thanks, its a lot of fun in the sun.