Pololu Simple - Manual (Page 53)

is being pulled down a hill by gravity, the extra voltage generated by the motors might trigger a VIN error and the
controller would attempt to stop your robot’s descent by braking.
The VIN multiplier offset is a calibration factor used in computing VIN. The default value of 0 should work fine for
most purposes. If you have a multimeter or another accurate way of measuring voltage, you can click the Learn…
button to have the software automatically set this number for you. If you find that the VIN reading shown in the Status
tab is too high, you should decrease this number. If it is too low, you should increase this number.
Over-temperature Response
The Simple Motor Controller monitors its temperature using a sensor near the MOSFETs and protects itself from
burning up by generating an error when the temperature is too high. The Simple Motor Controller has two modes for
over-temperature response:
• Abrupt shutoff with hysteresis: This is the default mode. In this mode, the Over temperature error will start
occurring when the temperature exceeds the Over-temperature maximum and will keep until the temperature
drops below the Over-temperature minimum. In this mode, it will be obvious when you are having temperature
issues because your motor will shut down completely while your motor controller cools off.
• Gradual limiting: In this mode, whenever the temperature is between the Over-temperature minimum
and Over-temperature maximum, the magnitude of the motor speed will be limited. The speed limit is 3200
(100 %) when the temperature is equal to the Over-temperature minimum, and it decreases linearly with
temperature so that the speed limit is 0 when the temperature is equal to the Over-temperature maximum.
If the temperature rises above the Over-temperature maximum an over-temperature error will occur and the
motor will stop. In this mode, the motor will keep on running as the board heats up, but it might run slower due
to the temperature-based speed limiting.
RC Pulse Detection
These parameters adjust how lenient or strict the RC signal measurement is on the RC1 and RC2 lines. If you use
strict settings, your controller will shut down faster when the RC signal is lost and be less likely to act on corrupted
data. If you use lenient settings, your controller will be more likely to keep operating when the RC signal quality is
poor.
Consecutive good pulses is the number of consecutive good pulses that must be received before the controller starts
heeding good pulses and updating the channel value. The default value of 2 means that after 2 good pulses in a row
are received, the third one will be used to update the channel value. A value of 0 means that every good pulse results
in an update of the channel value. Increasing this number makes your settings more strict while decreasing it makes
them more lenient.
Minimum pulse period and Maximum pulse period specify limits on the amount of time allowed between pulses.
If a pulse is received too soon after a previous pulse, it is considered bad. If the pulses on the line stop, then the RC
input channel’s signal is considered invalid after an amount of time equal to the Maximum pulse period has elapsed.
The period of your RC signal is shown in the Status tab, so you can use that to help pick good values for these settings.
The Bad signal timeout is like an expiration time for the pulses. If the RC signal line is corrupted by enough bad
pulses that the channel’s value is not getting updated, then the RC input channel’s signal will be considered invalid
after an amount of time equal to the Bad signal timeout has elapsed. Increasing this number makes your settings
more strict while decreasing it makes them more lenient.
Miscellaneous
The Disable safe start option disables Safe-start violation error, which is described in Section 3.4 . In Serial/USB
input mode, this means that you will no longer have to send Exit Safe Start commands. In RC or Analog input mode,
Pololu Simple Motor Controller User's Guide © 2001–2014 Pololu Corporation
5. Configuring Your Motor Controller Page 53 of 101