CalFW: Measure and send Result via SPI

[LeilaPiri]

• the rPi sends the requested measurement mode (ADC 1-4, current/voltage, samplerate):
• js<{"MeasMode" : 0/1 for current/voltage,
  "MeasChannel" : Bit combination of 4 bit to select a combination of ADC1-4,
  "MeasRate": sample rate in Hz
  }
• the rPi sends a command to start Measurement with a fixed duration in ms:
• js<{„MeasStart“ : t}
• The SAM measures the selected channels and saves the measured values
• SAM sends the results back via SPI (This has to be discussed, how to do that)

Definition of Done

• code for mentioned task is complete. examples & documentations are complete.

• build chains are tested

• corresponding branch is closed

• merging is done

[begodev]

SAM will send result as a file (binary array) via small communication protocol extension