tracking system notes

buckets system:

for each type of value we need to break its ranges into several buckets

buckets might be different sizes
some buckets might have a less than or greater than value range, others might be between two value ranges

could just be a whole series of arrays
if statements


struct bucket_item {
int min_value;
int max_value;
byte count;
}

Parameters to store in buckets:

heading (0-360, 10 degree increments) 10 bytes + 40 bytes
wind direction (0-360, 10 degree increments) 10 bytes + 40 bytes
roll (-60 to +60 10 degree increments, need a beyond -60/+60) 10 bytes + 40 bytes
pitch (-60 to +60 10 degree increments, need a beyond -60/+60) 10 bytes + 40 bytes
motor battery current (0-3, 15 0.2 amp buckets, need a beyond 3. Change to integers, make it 0-30.) 15 bytes + 60 bytes
motor battery voltage (6-9, 15 0.2 volt buckets, need a below 6 and above 9.) 15 bytes + 60 bytes
computer battery current (0-1, 5 0.2 amp buckets, need a beyond 1. Change to integers, make it 0-10.) 15 bytes + 60 bytes
computer battery voltage (3-4.6, 8 0.2 volt buckets, need a below 3 and above 4.6.) 8 bytes + 32 bytes
rudder position (-5 to +5, 10 buckets) 10 bytes + 40 bytes
sail position (0 to +5, 5 buckets) 5 bytes + 20 bytes

total data representation: 108 bytes
total range representation: 432 bytes

To keep counts in 8 bit range we can only sample once every 4 seconds, if transmitting every 15 minutes.

3.22 mV resolution, 242.3 mV/Volt, 73.2mV/amp  0.044 amp resolution, 0.13 volt resolution

Should we try to use a uLog to track all power consumption? Could do an incremental watt hours meter, would know how much battery is left. Does voltage tell us this anyway?
Do we want a realtime clock module? Less power than the GPS. Could use arduino to track time though. 

things to transmit:

heading bucket
wind bucket
roll bucket
pitch bucket
current buckets
voltage buckets
temperature x2 instant
lat/lon x2 instant


message format:


126 bytes total

3 credits per message
1 message every 15 min

4996 credits available 

1665 messages

at 4 per hour = 416 hours, 17 days