90. KL25Z Status Lights
The Pinscape firmware blinks the LED on the KL25Z to indicate its
system status. This is a quick way to check if the Pinscape software
is operating normally (or, at least, to check if the software
thinks it's operating normally, which might not always be the
same thing!). If you suspect that something's wrong, or you're not
seeing expected input on the PC, the LED lets you check at a glance
what the Pinscape software thinks about its current health.
Here are the various flashing patterns you might see and what they
- Long blue/green lights, alternating about every second:
normal healthy operation.
- Long yellow/green lights, alternating about every second:
normal healthy operation. The device has a good USB connection and
is running normally. However, the plunger hasn't been calibrated
yet, so you should run the plunger calibration process to finish
- Short yellow flashes, every couple of seconds: the device
has just restarted and is trying to connect to the PC via USB.
- Two short red flashes in rapid succession every couple
of seconds: the USB connection to the PC was broken. This can happen
if the USB cable is physically unplugged or the connection is
broken at a software level. Software disconnections can happen due
to software errors, and can also happen if the Windows USB drivers
- Long red/yellow lights, alternating: USB data transmission
problems are occurring. The device still has a connection to the
PC (or so it appears to the device), but the PC isn't acknowledging
transmissions. The device will try to restore the connection
automatically when this occurs, so this condition is usually
short-lived; the device will usually either return to normal within
a few seconds or will reboot itself to try to reset the connection.
- Medium blue flash, about half a second each: the TV ON
delay timer is running. This means that the power to the secondary
PSU has just been turned on, and the TV ON timer is waiting for the
configured delay time before turning on the TVs. You'll only see
this if the TV ON feature is enabled.
- Fast red/purple, alternating: the device is out of memory.
This means that the programmed configuration is too complex. The
KL25Z has a limited amount of memory, and each feature enabled in the
configuration consumes some of that. It's possible in principle to
exceed available memory by enabling too many features simultaneously.
This error should only occur immediately after a reboot, since
the software allocates all memory up-front during startup and uses a
fixed memory configuration from that point on. So you'll never see
this happen spontaneously because of something you're doing during a
pinball game session, for example. And at the moment, it really
shouldn't be possible to trigger this condition at all with any
real-world configuration. But you could probably do with a concerted
effort to max out every possible configuration option. If you do
happen to trigger this error, note that it will keep happening again
every time you reboot, since it's a function of the saved
configuration. The only way to clear it is to reset to the default
configuration by reinstalling a fresh copy of the Pinscape software.
Re-purposing the LED for feedback output
The status indicator LED on the KL25Z is connected to GPIO ports
(three of them - one each for the LED's red, green, and blue channel),
which means that it's under the control of the Pinscape software
program. That much is probably obvious given that the software uses
the LED to display the status light patterns listed above. But it
also means that you can assign the LED elements as feedback device
outputs. The Config tool lets you assign the GPIO pins associated
with the LED to DOF output ports, exactly like any other GPIO pins,
in the Outputs list on the Setting page.
If you do assign an LED element as a DOF-controlled output port, the
Pinscape software will cede the LED port to your control, and won't
try to use it as a status light. That means that the
flash patterns listed above won't appear if you take over the LED for
output port use. Obviously, the LED can't serve two masters, so the
Pinscape software gives precedence to your settings.
Why would you want to use the LED as a feedback device? The main use
case I see is testing. If you want to test a new DOF
configuration on your PC, for example, and you haven't set up any
external feedback devices yet, the on-board LED could be used for a
quick test that DOF signals are getting through to the KL25Z.
Finally, I'll point out a couple of odd quirks to the way the LED is wired on
The first quirk is that the LED channels are wired in "active low"
fashion, meaning that each LED color turns on when the voltage
on its GPIO pin is off. When setting up the LED elements as
outputs in the Config Tool, just be sure to enable the "Active Low"
option for each port. If the LED shows the opposite of what you want
(the LED is on when you want it off, off when it should be on), you
probably just need to go set the Active Low option.
The second quirk is way the LED connections are wired. The red and
green LED elements are wired to GPIO ports (PTB18 and PTB19,
respectively), but this is all purely internal within the KL25Z
circuit board: they're not wired to any external pins. Strangely,
though, the blue LED element (PTD1) is wired to an external
pin. So you can use port PTD1 to control something wired externally
in addition to controlling the blue LED element. I don't recommend
doing that, since it's pretty confusing to think about, but if you
were in a pinch and absolutely needed one more external GPIO pin for
some external control circuit, it would work. The blue LED would just
be sort of dragged along with whatever you were doing with the
external port, so you'd have to put up with the blue LED turning on
and off in concert with the external circuit.
Using PTD1 for button input
The blue segment of the status LED is wired to GPIO port PTD1, which
is also wired to one of the pins on the KL25Z's main pin headers (J2
pin 12; see KL25Z Pin Out
). The pin header wiring means
that you can use PTD1 for other purposes besides controlling the blue
LED - but if you do, it requires some special handling, because the
blue LED connection is hard-wired on the board and can't be changed
(The red and green segments are also wired to GPIO ports internally,
but they don't have any pin header wiring, so there's no way to use
those ports for anything other than the LED connections.)
You can use PTD1 as a feedback device output port simply by assigning
it in the config tool. Assigning it as a feedback output will prevent
the Pinscape firmware from using it as part of the status indication.
However, it doesn't change the internal hard-wiring between PTD1 and
the blue LED, so the blue LED will now turn on and off in sync with
any external feedback device you wire there. (Actually, in sync, but
opposite: remember that the LED uses "active low" wiring, so the blue
LED will turn ON when the output port is OFF, and vice versa.)
You can also use PTD1 as a button input, again, simply by assigning it
as a button input in the Config Tool. With this use, the blue LED
segment will stop acting as part of the Pinscape status indicator;
instead, it'll just light up whenever you press the button.
If you do use the PTD1 header pin for one of these uses, and it
bothers you that the blue LED is affected by the port status, you can
physically modify the KL25Z to sever the connection to the LED. The
procedure is described in KL25Z Pin Out
. Be aware that
severing the blue LED connection will change the Pinscape status light
patterns accordingly, since the Pinscape firmware won't be able to
light up the blue LED any longer.
OpenSDA status LED
There's a second status LED on the KL25Z: a smaller monochrome green
LED, close to the USB connectors. This one shows the OpenSDA
(firmware loader) status:
- Solid green means "OK" - the OpenSDA port is connected and the
boot loader is awaiting commands
- Slow flashing means that a firmware update is in progress
- Rapid flashing means that an error has occurred
If rapid flashing appears, indicating an error, you can clear it by
unplugging both USB cables, waiting a couple of seconds, and then
plugging the cables back in. That should reset the device and
return the status indicator to solid green. Once an error condition
appears, it stays there until you clear it manually.
If you see an error indicator, it's not due to anything you did wrong.
It's just random bugs in the KL25Z boot loader, as far as I can tell.
That part of the software comes from the KL25Z's manufacturer, so it's
not something I can easily fix. An error condition on the OpenSDA
side won't affect normal Pinscape operations, so you can ignore the
little green LED most of the time. It only matters when you're trying
to update the Pinscape firmware.