Thread: Discussion olliw co mixer build
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Old Sep 22, 2012, 02:00 AM
OlliW is offline
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Joined Sep 2009
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nice job, sir

you even went with the poti option, cool.

as regards the LEDs, info can be drawn from the original Arduino page, So, the pro mini has two leds, one which is connected to the power and hence just works as a power indicator, and a second one which is connected to the microcontroller and can hence have different functions depending on the code, let's call it the status led. The power indicator led is located in the middle of the board, while the other led is located near the reset button. So, in your case

blue led = power indicator, flashes permanently as long as the pro mini is powered

green led = status led, shows the status of the coax mixer (as programmed into the firmware code you flashed)

So, only the status led (green in your case) is of relevance for you.

As regards the flash signals of the status led: The coax mixer firmware is a descendent of the GA250 gyromixer firmware (so to say it's little cousin), and accordingly it functions very similar in many respects. This is to say that it can be useful to look up the info on the GA250 gyromixer project if a piee of info is missing, since some aspects of the functioning are very similar (for instance, you also can use your USB flash adapter to set paramters remotely via a PC, or use the a programming box for setting the paramters remotely "in-field"... but these are advanced options). Info on the GA250 gyromixer project can be found here:

The useful piece of info here is the description in this post,, and scroll down to Functions of the GA250 Gyromixer. The GA250 has TWO status leds, while the pro mini has, as discussed in teh above, only ONE status led, so the one status led on the pro mini takes over both.

The only difference (if I recall correctly) is that the coax mixer first flashes the status led for ca 1s after power up, but then follows exactly the scehem as given in the GA250 gyromixer post, i.e.

status led for ca 1s after power up
(A0) Initialization and startup, the mixer first waits for a valid signal to come in from the reciever. The LED is blinking very fast.
(A1) Rx signals recieved (on both mixer inputs), The red LED is blinking fast.
the mixer waits for as long until Throttle becomes high or low
|-> Thro is high -> (B) Thro range programming mode
Thro is low
(C) Thro low mode
(D) Flight mode


In order to diagnose your issue that the motors are not responding, it would be needed to know in which status your mixer is, i.e., please describe more precisely what the status led (green in your case) is doing after power up... do you see e.g. the transition from very fast to fast blinking?

BTW: could you please leave a comment on my web blog telling that you openend this thread (with a link maybe) and transfered the discussion to her? Thx
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Last edited by OlliW; Sep 22, 2012 at 02:26 AM.
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