▪
Red LED on solid, green LED off:
This is the first stage of the learning sequence in which the
TReX is attempting to learn the neutral values of each channel. This phase should last around
two seconds. Do not touch the RC/analog sticks while the red LED is on or you could cause
learning to fail.
▪
Status LEDs flash rapidly five times:
When the TReX is through learning the neutral values, it
will flash the status LEDs five times to indicate which channels had neutrals successfully
learned and which channels failed neutral learning. A green flash indicates success for the
corresponding channel; a red flash indicates failure. If all five channels fail to learn neutral
values, the learning process stops, otherwise it continues to the next phase, which is learning
the values of the extremes. Once this last learning phase is complete, the status LEDs will
again flash five times to indicate whether the corresponding channel was successfully learned.
This final five-flash sequence will repeat until the TReX is reset.
▪
Red and green LEDs both on solid:
This is the second and final stage of the learning sequence
in which the TReX is attempting to learn the maximum and minimum values for each
channel. This phase lasts around ten seconds, during which time you should move the control
sticks to their extremes. Make sure to hold each channel at each extreme for at least 0.5
seconds.
◦ While in Firmware-Upgrade Mode (see
Section 6
):
▪
Red and green LEDs alternate around once per second
: The TReX is waiting to see if it
should enter firmware-upgrade mode. This happens when the TReX is in serial mode (i.e.
there is no mode jumper in place), the mix jumper is in place, and the serial out (SO) pin is
grounded. This last condition can arise if the TReX is connected serially to an unpowered
microcontroller. Ungrounding the SO pin will cause the TReX to startup as normal; removing
the mix jumper will put the TReX into firmware-upgrade mode, which will cause the red and
green LEDs to start alternating four times faster.
▪
Red and green LEDs alternate around four times per second:
The TReX is in firmware-
upgrade mode and is waiting for the short between the serial out (SO) pin and ground to be
removed.
▪
Green LED flashes briefly once per second:
The TReX is in firmware-upgrade mode and is
waiting for the correct initial serial input sequence. The TReX enters this state when the short
between the serial out (SO) pin and ground is removed after the mix jumper has been
removed.
▪
Red LED flashes:
There was a faulty input to the bootloader that has caused the bootloader to
revert to waiting for the correct initial serial input sequence. Note: once the firmware upload
is complete, the TReX will reboot and the red LED may flash as part of the startup sequence.
This is not an indication of a firmware-update error. See the firmware-update section for
further details.
▪
Green LED rapidly flashes:
Everything is proceeding as expected during the firmware
upgrade process. Each successfully uploaded data packet causes the green LED to flash.
3.e. Automatic Calibration for Your RC/Analog Controller
The TReX has the ability to automatically calibrate itself for your particular RC or analog controller. We strongly
recommend you use this feature to calibrate your TReX as it can result in a substantial increase in performance. You
only need to perform the calibration once, but you should recalibrate if you ever change controllers. The TReX can
simultaneously store a set of analog calibration values and a set of RC calibration values; the calibration values used
depends on the mode of operation (or on the value of the “channel input source” parameter if the TReX is running in
serial mode).
Pololu TReX User's Guide
© 2001–2009 Pololu Corporation
3. Getting Started
Page 10 of 22
