Table 1—The packet schedule was created to keep the system simple and flexible, and functioning in real time. The slower sensors (e.g., temperature sensors) are low priority. The sensors with more important data, like engine RPM, are sent on every radio transmission. The 0.125-s timing gives eight readings per second and uses the ATmega128’s internal timer to control the schedule.

 

Sensor Time t1 t2 t3 t4 t5 t6 t7 t8 t8-t1
2 axis X_Accel X X X X X X X X P
2 axis Y_Accel X X X X X X X X I
A/D FL_Susp X X X X X X X X N
A/D FR_Susp X X X X X X X X G
A/D RL_Susp X X X X X X X X  
A/D RR_Susp X X X X X X X X T
Counters FL_Speed X               O
Counters FR_Speed X                
Counters RL_Speed X               P
Counters RR_Speed X               C
A/D RPM   X   X   X   X  
A/D Temp   X   X   X   X  
Thermocouple Ex1_Temp       X          
Thermocouple Ex2_Temp       X          
Thermocouple Ex3_Temp       X          
Thermocouple Ex4_temp       X          
  Totals 10 8 6 10 6 8 6 10 1