I'm trying to find out how long my batteries can last with different parameters. Since I'm not a great electrician (and barely know Ohm's law) I have a few questions.
1. What does the getVoltage() function really return? If you read the voltage at time A and B while nothing is attached and do the same while a motor is running, will the results (voltage at time A and voltage at time B) say anything about how much of the battery a motor uses? (I'm trying to find out how much the motor uses at different speeds/power levels).
My goal is to calculate which combination (mostly the motors) will consume the most battery power.
2. In the NXT Hardware Developer kit pdf it says that there is 4.3V output supply for input and output. But how do you convert this to mA? (i.e. how do I know how much mAh a sensor/actuator uses?).
On figure 11 they have a graph that lists max mAh and normal mAh when there is load on the motors and when there is none.
It also lists 9, 5 and 3.3 V but what do these numbers mean?
Above the table it says that the switch mode power supply generates a 5 volt power supply from the batteries and from the 5 volt power supply, another 3.3V supply is generated for the ARM7 processor and the bluecore chip.
If anyone has some experience with the lejos hardware (or electronics in general) or knows someone who does, please let it know.