Green usb led, Red led, Yellow led – Pololu Wixel User Manual
Page 6
Wixel indicator LEDs.
Different Wixel applications may use different sets of these peripherals. Consult the application documentation for
details on the behavior of the I/O lines.
The pinout and peripheral diagram at the top of this section is also available as a
(145k pdf).
The Wixel has three indicator LEDs:
Green
USB LED
The green LED is powered from USB, so it can only be turned on
when USB cable is connected and supplying power to the Wixel.
While the Wixel is in bootloader mode (i.e. the app is stopped), this
LED is used to indicate the USB status of the device. When the
Wixel USB Bootloader connects to USB, the green LED starts
blinking slowly. The blinking continues until the bootloader
receives a particular message from the computer indicating that the
Wixel USB Bootloader drivers are installed correctly (see
for driver installation instructions). After the bootloader gets this
message, the green LED will do a double-blinking pattern. The
green LED also turns off during USB Suspend Mode, which
happens when the computer goes to sleep or shuts down the USB
port for any other reason.
While the Wixel is running its app, the behavior of the LED depends
on the app. The standard apps provided by Pololu all behave as follows: When the app connects to USB, the green
LED starts blinking slowly. The blinking continues until the app receives a particular message from the computer
indicating that the app’s drivers are installed correctly. After the app gets this message, the green LED turns solidly on.
The green LED also turns off during USB Suspend Mode, which happens when the computer goes to sleep or shuts
down the USB port for any other reason.
Red
LED
While the Wixel is in bootloader mode (i.e. the app is stopped), this LED indicates whether there is an application on
the Wixel. If there is no application, the red LED will be on. Otherwise, it will be off. By default, the Wixel does not
have an application on it, so this LED will be on the first time you power your Wixel.
The P2_1 pin is connected to the red LED, so this line will go high when the red LED is on and otherwise be pulled
low.
While the Wixel is running its app, the behavior of this LED depends on the app. See the documentation of your
particular app for more details.
Yellow
LED
While the Wixel is in bootloader mode (i.e. the app is stopped), this LED turns solidly on and flickers whenever the
bootloader receives a command from Wixel software on the computer. The Wixel Configuration Utility queries the
state of the bootloader once per second, so if the Wixel Configuration Utility is open then the LED will flicker once
per second. While the Wixel is being programmed, the yellow LED will constantly flicker.
Pololu Wixel User's Guide
© 2001–2014 Pololu Corporation
1. Overview
Page 6 of 64