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Name Hex
Dec
Size Description
Graph Pointers
177
8
See section XIV
Graph data
185
3898 See section XIV
Log
Average
Temperature FFC 4092 1 Set
this
value to zero to enable logging of average
temperature values. A non-zero value causes the
temperature at the end of the archive period to be logged.
Password CRC
FFE
4094
2
WeatherLink uses these two bytes to hold the CRC of a
password in order to provide some protection from
unauthorized access. This is only enforced by software
implementation. The value 0xFFFF indicates that no
password is set.
XIII.
Common Tasks
This section describes how to perform several common tasks, especially ones that need to be
done in a particular way.
1.
Setting Temperature and Humidity Calibration Values
The 28 EEPROM bytes starting at address 50 (0x32) contain the calibration offsets for
temperature and humidity values. Unfortunately, if you modify these values in the EEPROM, the
new calibration value will not take effect until the next time the Vantage receives a data packet
containing that temperature or humidity value. In order to update the Vantage display with the
new calibration values, you have to follow this procedure.
Create a data structure to hold all of the calibration values, and one to hold the results of the
"
CALED
" command.
1.
Use "
EEBRD 32 2B
" to read in the current calibration offset values.
2.
Use "
CALED
" to read in the current calibrated sensor values.
3.
Determine what the un-calibrated sensor values are by subtracting the calibration offset
from the data value. Make sure that you only do this if the sensor has valid data (i.e. not
0x7FFF, or 0xFF).
4.
Determine and write the new calibration values into the EEPROM using "
EEBWR 32 2B
".
5.
Use "
CALFIX
" to send the un-calibrated sensor values to the Vantage to have the display
update using the new calibration values.
You can use the "
EERD 32 2B
" command if you want to, but it is harder to process.
You do not have to set all of the calibration values, but you do have to send all of the sensor data
values in the "
CALFIX
" command.