Main Site Documentation

Startup behaviour of G120 GPIO's


#1

Hi,
we use a G120 based custom board without Display.
The board has 8 digital Outputs.
4 of them are connected to Green 0 to Green 3 (P1_20 … P1_23)
the other 4 are connected to SPI3_Mosi, COM4_TX, COM4_RX, COM3_OE (P1_1, P4_28, P4_29, ?)

The problem is that the 4 ‘Green’ GPIO’s get high on reboot for a short time.
The other 4 does not.

I assume that this might happen because the G120 wants to display something on the display when booting.
Is ist possible to deactivate the Display completely.
Or is there a other reason for such a behaviour?

We have a pure NETMF Project. There is no Gadgeteer involved.
Firmware is 4.2.9


#2

The next firmware will default to no display to cover your issue and similar issues.


#3

With next Firmware you mean 4.2.11?
Any idea when it is released?

Any idea how we can prevent this now?
Unfortuenatelly the Green 0 GPIO triggers an safety critical event.
I know we should have checked for this earlier, but now we need a quick solution.


#4

You can’t fix without next release but have you tried adding pull down resistors?

Next SDK is days away, no set date.