request: replace calcAverage() for sensor values with interesting peak()

[derFliegendeHamburger]

now:

• msrc samples the sensors' data and applies calcAverage() before values get stored for later transmission.
  averaged values hide interesting short term spikes, the sampling rate is of little use for averaging

Wanted:

For current and temperature, the highest sensor value in any interval between two adjacent transmissions is most interesting;
for rpm and voltage, the lowest sensor value in any interval between two adjacent transmissions is most interesting;
This would transmit and make accessible more valuable info than an averaged value

• sample sensors' data and apply a peak() function to preserve the most interesting value for the next transmission.
• after transmission, reset the stored peak values and start again.