AEM Commands #

Use the AEM commands to measure current, voltage, and temperature, as well as to calibrate the AEM.

For more information about AEM see the AEM overview.

aem calibrate #

Manually runs the AEM calibration. VMCU is disabled during AEM calibration.

Command Line Syntax

$ aem calibrate

Command Line Example

$ aem calibrate
Calibrating...OK!
=== Calibration Info ===
 - Low Range -
  HG Offset cal/uncal [diff]: -0.0187/-0.0183 [-0.0004] mA
  LG Offset cal/uncal [diff]: -0.0185/-0.0183 [-0.0002] mA
 - High Range -
  LG Offset cal/uncal [diff]: -0.0438/-0.0183 [-0.0255] mA
 Temperature at last calibration: 37.64 deg C
 Cal. no:      2
 Time (local): 258376760938 us
 VMCU:         3.300 V
 Cal. samples: 1000000 samples
 --- Calibration point 0 ---
  Cal. resistance: 4.707000e+02 Ohm
  Expected:        6.989581 mA
  High Gain:       3.999031 mA
  Low gain:        7.033418 mA
 --- Calibration point 1 ---
  Cal. resistance: 2.200070e+04 Ohm
  Expected:        0.149504 mA
  High Gain:       0.168107 mA
  Low gain:        0.168035 mA
 --- Calibration point 2 ---
  Cal. resistance: 1.000000e+12 Ohm
  Expected:        0.000000 mA
  High Gain:       0.018725 mA
  Low gain:        0.021894 mA

aem avg #

Gets the latest block average current measurement from the AEM.

Use the option -r to enable repeated measurements, with one averaged value reported every 20 milliseconds. The PK has a new block average ready roughly every 25 ms, while the WPK has a new block average ready roughly every 4 ms. Send a new line to exit the loop.

Command Line Syntax

$ aem avg [-r]

Command Line Example

$ aem avg
0.000076 mA

aem calinfo #

Retrieves information about the active calibration. If the externally measured temperature or the configured voltage has changed significantly, a recommendation to recalibrate the AEM will be displayed.

Command Line Syntax

$ aem calinfo

Command Line Example

$ aem calinfo
=== Calibration Info ===
 - Low Range -
  HG Offset cal/uncal [diff]: -0.0187/-0.0183 [-0.0004] mA
  LG Offset cal/uncal [diff]: -0.0175/-0.0183 [00.0008] mA
 - High Range -
  LG Offset cal/uncal [diff]: -0.0317/-0.0183 [-0.0133] mA
 Temperature at last calibration: 24.20 deg C
 Cal. no:      1
 Time (local): 87930 us
 VMCU:         3.300 V
 Cal. samples: 1000000 samples
 --- Calibration point 0 ---
  Cal. resistance: 4.707000e+02 Ohm
  Expected:        6.990707 mA
  High Gain:       4.004747 mA
  Low gain:        7.022371 mA
 --- Calibration point 1 ---
  Cal. resistance: 2.200070e+04 Ohm
  Expected:        0.149539 mA
  High Gain:       0.168258 mA
  Low gain:        0.167082 mA
 --- Calibration point 2 ---
  Cal. resistance: 1.000000e+12 Ohm
  Expected:        0.000000 mA
  High Gain:       0.018728 mA
  Low gain:        0.020252 mA
AEM should be recalibrated due to a temperature change since last calibration from 24.20 deg C to 37.91 deg C

aem temp #

Retrieves the temperature reading from the sensor located near the AEM circuitry.

Command Line Syntax

$ aem temp

Command Line Example

$ aem temp
Temperature: 38.84 C

aem current #

Retrieves the average current from the AEM.

Use the option -r for repeating measurements, with one averaged measurement reported per second. Send a new line to exit the loop. The output also includes the raw low gain (LG) and high gain (HG) current measurements.

Command Line Syntax

$ aem current

Command Line Example

$ aem current
AEM current: 7.77 mA    [LG: 7.8073] [HG: 0.5820]

aem info #

Displays miscellaneous AEM information.

Command Line Syntax

$ aem info

Command Line Example

$ aem info
Filter mode             : average [2]
AEM LG lp filter length : 65
AEM LG lp filter gain   : 32796
AEM HG lp filter length : 65
AEM HG lp filter gain   : 32796
HG offset: 0.000
HG bias  : 15.070 uA
LG offset: 0.000
LG bias  : 0.041 mA

aem statistics #

Runs measurements over a specified number of samples and prints statistics for the measurements. If the number of samples is not specified, 10,000 samples will be collected.

Command Line Syntax

$ aem statistics [ samples ]

Command Line Example

$ aem statistics
Sample Count: 10000
       Mean                                Standard deviation
LG:    0.5831 [mA]   26.6358 [LSB]         0.0580 [mA]    6.1549 [LSB]
HG:  582.4518 [uA] 4085.1316 [LSB]         3.2378 [uA]  490.4147 [LSB]

aem voltage #

Retrieves the currently measured voltage.

Use the option -r for repeating measurements, with one measurement every 100 milliseconds. Send a new line to exit the loop.

Two voltages are printed:

• The first is the voltage measured when the last current measurement completed.

• The second (in brackets) is the voltage measured at the time the command was executed.

Command Line Syntax

$ aem voltage

Command Line Example

$ aem voltage
AEM voltage: 3.3529 [3.3534]