Weird problem with i2c splitter and external LED

Have built up my hexa and added the I2C splitter to it, all is working A.OK so far :slight_smile: now for the problem… The external LED works grand , but won’t work period when the GPS puck is plugged into the splitter along with the LED… as I would like to use both compasses and the LED at the same time…

is this a known fault or something new…:open_mouth:

cancel that… just tried it all again and it’s working… , ahh the joys of RC hobbies… and I’m having grand conversations with myself on here these last few days…:scream:

nope, now it’s not… looks like a hit or a miss affair here with it working…

What hardware are you using. The GPS is serial and is plugged into the serial port and the LED is on the I2C port along with the external compass if you have one. They should be using different addresses otherwise you have a loose wire.

Mike

Pixhawk, along with ublox7 GPS with compass, also using the crius splitter… it’s working at the moment… although sometimes the external LED will illuminate and then extinguish… so it could be a loose connection somewhere in the loop…

Sound like your external LED has a problem. Maybe loosing power. The Pixhawk sends it the colors to display. If it gets no update it will stay at the current color. Yours goes out indicating a possible power lose or low power…

Mike

I have ordered a new external LED/USB unit with cables… see if that makes a difference …:+1:

I had the same problem and didn’t sort it out with two different external LED’.
It seems to me that the LED and the compass are both using the same address, but couldn’t get any info about the address, or the way to change it.
Only that it should work.

And indeed, if I connect only one of them, either LED or compass I have no problems, but with both connected, the led isn’t working at all.
@iseries
what do you mean by?

Hmm… well glad to know that it’s just not me that is having hassles with this…

The LED is at one address and receives the color to display. The HMC5883 sends magnet location back to the flight controller. Since they are on the same bus they need different addresses otherwise they don’t know who is talking or receiving the information.

The LED is at address 55 (AA for write and AB for read request) and the HMC5883 is at 1E (3C write and 3D read request).

So if they did use the same address the LED colors would just be the same color and not just go off.

Mike

Hi Mike,

I misunderstood what you wrote about a loose wire.
I though the physically loose wire could somehow change the address, silly me.

So, if we assume they have the correct addres (55 vs 1E) do you have an idea what else could prevent them from working when they are both connected to the I2C splitter.
I have even tried to use another I2C splitter, but I keep getting the same problem.

Davyg,
I have exactly the same issue - external LED works some of the time. Am using the same hardware.
Have tried several LED’s & GPS/Compass modules, same result.
Power cycle the Pixhawk & eventually the LED will work, could take several attempts…
It appears that only one LED will work at a time, never both (on-board Pixhawk & external)
I just deal with it for now, would be nice to resolve though…

philpet

Davyg,
I have exactly the same issue - external LED works some of the time. Am using the same hardware.
Have tried several LED’s & GPS/Compass modules, same result.
Power cycle the Pixhawk & eventually the LED will work, could take several attempts…
It appears that only one LED will work at a time, never both (on-board Pixhawk & external)
I just deal with it for now, would be nice to resolve though…

Yeah I did discover that , bit of palaver if and when one is out in the field (so to speak), it should work each and everytime and not intermittently… is this something that the developers need to address???

thanks for all replies so far folks , much appreciated…:+1:

I am using 3.3.2 rather than 3.2 but I have an external usb/led (like this - http://www.ercmarket.com/pixhawk-external-led-and-usb-module.html) on my quad and it work’s first time every time. It is plugged into the i2c splitter that came with my Pixhawk along with the external compass of my m8n GPS module.

Possibly an issue with 3.2 that’s been resolved with 3.3?

I am using both CRIUS ic2 splitter and external USB/LED unit…

an ongoing problem by the looks of it…lifted from the 3.3 section Outdoor LED and GPS do not work at a time

According to this, we have a hardware problem (too strong pull-up resistors) in one of our units (or both).
It would be good if we have a method of testing which one is problematic in order to replace it, but it seems the only way is trying it on a friends copter which has them working ok, and which I don’t have (they don’t use i2c splitter or pixhawk).
My electronic skills are not so good, but maybe someone with more knowledge has an idea how to find (and replace) the problematic pull-ups?

after upgrading to latest firmware the external LED and compass appear to be working OK… though time will tell…LOL