Weather.c

Read multiple temperatures from thermistors, light, wind speed and direction
and send periodic info back to PC by RF using Mailbox RF protocol

*********** REVISION HISTORY **************************
Rev 1   Fully operational.  Added battery voltage monitoring.  Added send time
        selection.  Moved ADC enable to interrupt routine - normally off.

Rev 0   Creation        6/4/02
		Operational
*********** OPERATION *********************************

Send rate switch settings:
	 	  	Switch      3   2   1   0
1 second                O   O   O   O			
2 seconds               O   O   O   X
5 seconds               O   O   X   O
10 seconds              O   O   X   X
30 seconds              O   X   O   O
1 minute                O   X   O   X
2 minutes               O   X   X   O
5 minutes               O   X   X   X
10 minutes              X   O   O   O
15 minutes              X   O   O   X
30 minutes              X   O   X   O
1 hour                  X   O   X   X
1.5 hours               X   X   O   O
2 hours                 X   X   O   X

*********** RESOURCES *********************************

Processor: AT90S4433
Crystal: 4 MHz
Flash size: 
RAM Used: 
EEPROM Used: 0

Pins used:

PB0  Send Rate Bit 0
PB1  OCR1 Output - Connect to ICR0
PB2  Scan Rate Bit 1
PB3  
PB4  
PB5

PC0	 Temperature On Board
PC1	 Temperature 2
PC2	 Temperature 3
PC3	 Temperature 4
PC4	 Light On Board
PC5  Battery Voltage (Actual volts / 4)
 

PD0  Send Rate Bit 2
PD1  UART Txd
PD2  INT0 - Wind Speed (future)
PD3  Send Rate Bit 3
PD4  T0 - from OCR1
PD5  Run LED
PD6  Sensor Power
PD7  RF Xmt Power
  
 

Interrupts:
INT0 - Wind Speed Counter

Timers:

TCNT1 output compare triggers TCNT0 to create a long delay timer.
Exact settings set into OCR1.  Set coarse delay times using prescalers
as follows:
TCNT1 - 4MHz / 1024.  Set OCR1 to 458 per minute of delay. Toggle output.
TCNT0 - 4MHz / 1024. Set TOF interrupt to run desired routine 
		
