Spider/LCD Issues - Exception raised

NETMF & Gadgeteer
1

Hi All,

I have a Spider running firmware v4.2.7.0 and have been developing with the CP7 as a target display, unfortunately the few issues that have arisen with this combination mean I am looking at alternative displays. I recently received a 4.3" LCD which caused an exception when touched so I went back to basics and connected up the T35 display into the Spider board with no other peripherals connected, this also caused the same exception.

I have created a new Gadgeteer NETMF v4.2 application, connected only R/G/B and Touch to 14, 13, 12 and 10 respectively, added no code whatsoever and launched the application. As soon as the screen is touched I receive the following :

Using mainboard GHI Electronics FEZSpider version 1.0
Program Started
#### Exception System.NullReferenceException - CLR_E_NULL_REFERENCE (4) ####
#### Message:
#### Microsoft.SPOT.Application::OnEvent [IP: 0090] ####
#### Microsoft.SPOT.EventSink::ProcessEvent [IP: 0023] ####
#### Microsoft.SPOT.EventSink::EventDispatchCallback [IP: 0014] ####
A first chance exception of type ‘System.NullReferenceException’ occurred in Microsoft.SPOT.TinyCore.dll
An unhandled exception of type ‘System.NullReferenceException’ occurred in Microsoft.SPOT.TinyCore.dll

I have searched the forum and this exception appears to crop up but with no answer/solution that I can find. I have also performed a firmware update to ensure everything is vanilla and I still get the same issue.

Please can someone help ?

Could I have a faulty Spider board ? If so how do I go about getting this replaced ?

I posted regarding an issue I have had on Socket 10 in the past that was creating the ‘Failed to perform I2C transaction’ exception, this appear to be solved with the latest firmware, could these issues be related ?

Is it possible to call Tech Support at GHI to discuss this issue ? This product development has hit a number of unexpected stumbling blocks on the way with the LCD interfacing, I would appreciate any help available to get back on track and finalise some decisions on the display/hardware platform.

Many thanks in advance, Swifty.

2

Looks like there is no check if anything subscribed to an event. That would be my guess. Subscribe to the event with empty handler and see if exception will go away.

3

@ andre.marschalek - Valentin beat you this time… you will have to be faster to beat him. :slight_smile:

4

Wow, the name chage was pretty fast too. From Devine to Superhuman.
Cool.

5

Hi Guys,

Thanks ever so much for the quick replies ! The CP7 is working fine, without the event nothing happens (As expected), with the event subscribed I do see it firing.

The exceptions are being raised with the GHI T35 display and the other 4.3" display I have. These touch events appear to be handled at a lower level so there are not events I can hook into.

Cheers, Swifty.

6

Hi All,

Many thanks Andre, that worked for both the T35 and the 4.3" screen. I assume this was a newbie question based on the simplicity of the solution, however I really appreciate the quick answers.

Cheers, Swifty.