resonance_tester: Resonance testing and input shaper auto-calibration (#3381)

Signed-off-by: Dmitry Butyugin <dmbutyugin@google.com>

config/example-extras.cfg

@@ -569,6 +569,11 @@
 #   example, one could set this to "y,x,z" to swap the x and y axes.
 #   It is also possible to negate an axis if the accelerometer
 #   direction is reversed (eg, "x,z,-y"). The default is "x,y,z".
+#rate: 3200
+#   Output data rate for ADXL345. ADXL345 supports the following data rates:
+#   3200, 1600, 800, 400, 200, 100, 50, and 25. Note that it is not recommended
+#   to change this rate from the default 3200, and rates below 800 will
+#   considerably affect the quality of resonance measurements.
 #cs_pin:
 #   The SPI enable pin for the sensor. This parameter must be
 #   provided.
@@ -582,6 +587,45 @@
 #   These optional parameters allow one to customize the SPI settings
 #   used to communicate with the chip.
 
+# Support for resonance testing and automatic input shaper calibration.
+# In order to use most of the functionality of this module, additional
+# software dependencies must be installed; refer to docs/Measuring_Resonances.md
+# for more information.
+#[resonance_tester]
+#probe_points:
+#   A list of X,Y,Z coordinates of points (one point per line) to test
+#   resonances at. At least one point is required. Make sure that all
+#   points with some safety margin in XY plane (~a few centimeters) are
+#   reachable by the toolhead.
+#accel_chip:
+#   A name of the accelerometer chip to use for measurements. If adxl345 chip
+#   was defined without an explicit name, this parameter can simply reference
+#   it as "accel_chip: adxl345", otherwise an explicit name must be supplied
+#   as well, e.g. "accel_chip: adxl345 my_chip_name". Either this, or the next
+#   two parameters must be set.
+#accel_chip_x:
+#accel_chip_y:
+#   Names of the accelerometer chips to use for measurements for each of the
+#   axis. Can be useful, for instance, on bed slinger printer, if two separate
+#   accelerometers are mounted on the bed (for Y axis) and on the toolhead (for
+#   X axis). These parameters have the same format as 'accel_chip' parameter.
+#   Only 'accel_chip' or these two parameters must be provided.
+#min_freq: 5
+#   Minimum frequency to test for resonances. The default is 5 Hz.
+#max_freq: 120
+#   Maximum frequency to test for resonances. The default is 120 Hz.
+#accel_per_hz: 75
+#   This parameter is used to determine which acceleration to use to test a
+#   specific frequency: accel = accel_per_hz * freq. Higher the value, the
+#   higher is the energy of the oscillations. Can be set to a lower than the
+#   default value if the resonances get too strong on the printer. However,
+#   lower values make measurements of high-frequency resonances less precise.
+#   The default value is 75 (mm/sec).
+#hz_per_sec: 1
+#   Determines the speed of the test. When testing all frequencies in range
+#   [min_freq, max_freq], each second the frequency increases by hz_per_sec.
+#   Small values make the test slow, and the large values will decrease the
+#   precision of the test. The default value is 1.0 (Hz/sec == sec^-2).
 
 ######################################################################
 # Config file helpers