Hi
I use the IC2 splitter in my pixhawk, I have only two things connected to it. GPS and external led.
The GPS is the m8n and the external led is Crius.
GPS only reach the Ic2 the two central cables.
If i do not connect the GPS to the external IC2 splitter led works without problem but when I connect together external LED does not work.
What can be?
I thought the I2C was only for compass not GPS??
I think in this case “GPS” means the compass in the GPS module (it’s probably a combined GPS + compass module).
So, I can imagine two possible problems:
Does the LED work when only it is plugged into the Pixhawk? If “No” then the problem is probably #1. If it does work then it’s probably #2.
I don’t know which of the two (Compass or LED) has the hardware problem. It could be both. I think the only way to know is to find a friend who has a working set-up and try your compass on their setup and then your LED on their setup and see which of the two doesn’t work for them.
[quote=“rmackay9”]I think in this case “GPS” means the compass in the GPS module (it’s probably a combined GPS + compass module).
So, I can imagine two possible problems:
Does the LED work when only it is plugged into the Pixhawk? If “No” then the problem is probably #1. If it does work then it’s probably #2.
I don’t know which of the two (Compass or LED) has the hardware problem. It could be both. I think the only way to know is to find a friend who has a working set-up and try your compass on their setup and then your LED on their setup and see which of the two doesn’t work for them.[/quote]
Hi
Yes, you are right, meant compass. Both GPS and compass combined is same module.
External LED works when is alone plugged into Pixhawk.
In theory both separately run smoothly.
Compas insurance works well because I move separately internal and external and give me EKF error (do not point to the same place) when I see how the HUB moves in Mission Planner.
The second point you comment i do not understand well. When the compass is connected stop the Communication with the pixhawk? Can you explain that a little more please to try to find the solution? Thx
Hi again
I understand more what you mean. I found the wiring diagrams of GPS / Compass and IC2 port.
pixhawk.org/peripherals/sensors … iver_board
pixhawk.org/modules/pixhawk#pinouts
Those that I have are not exactly these but should work equally. Independently tested both modules appears to be functioning properly. Is there any way to check further?
It may be that in one of the modules are changed the SLC and SDA and still work well by themselves? when they are working alone?
Sorry, i speak from ignorance, as’m talking nonsense.
arruntus,
So if each works separately then it must not be a wiring problem. My guess is that the problems is that one (or both) of the devices have pull-ups that are too strong. I don’t think there’s really anyway to resolve that besides replacing them problem item. I think you’ll only know which one is the real problem by trying each out on a friends copter.
Hi
I know no one with pixhawk, I’m new at this. I will check the status on the tablet with Tower.
Later I will consider buying another led module or change GPS and check.
Thanks for the help 
Did you ever solve this? I have the exact same problem.
Hi
no, only use the USB and have disconnected the IC2, I have removed the splitter.
I think it is hardware problem, i will check the latest version and look again. I have assumed that it will not work but you never know…
Do u have the same external led?
exactly the same problem I am having with my Pixhawk… LED works everytime when plugged into the i2c port when I power up the system, or if it’s plugged into the splitter, once I plug in the compass to the I2C splitter then the LED works only intermittently… I am using both CRIUS units…
UPDATE: I updated to latest firmware, LED and compass plugged into I2C splitter is working (it does have the odd hiccup and won’t illuminate… but no where near as bad as it had been doing…)
Hello.
we are now facing the same problem but its GPS/compass (M8N) with PX4 Airspeed sensor
Separately they work just fine but not through i2c splitter.
Wiring is the same:
So, I have an impression that conflict somehow comes from SDA. Since SCL is just a clock… thoughts?
Firmware on Pixhawk is the latest for plane… and what if I will add later 2 model devices to i2c???
any idea?
thanks much,
–Hayk
Hello Guys. Anybody resolved this problem ? Is this even possible to connect this led without a problem and make it to work properly or we cant do that ?? I’m facing the same problem
