Max number of analog ports

Technical Java
1

Hi,

Is anyone out there using two 9201 analog breakouts with more than 8 ports total? We’ve come across a bug.

Steps to reproduce the bug:

Create a new Simple Robot project

Declare the following in the class (typing from memory, so please feel free to correct me):

AnalogChannel a1 = new AnalogChannel(1,1);
AnalogChannel a2 = new AnalogChannel(1,2);
AnalogChannel a3 = new AnalogChannel(1,3);
AnalogChannel a4 = new AnalogChannel(1,4);
AnalogChannel a5 = new AnalogChannel(1,5);
AnalogChannel a6 = new AnalogChannel(1,6);
AnalogChannel a7 = new AnalogChannel(1,7);

Now compile it, download it, and run it.
You will find that it compiles and runs ok.

Now add in the following declaration:

AnalogChannel b1 = new AnalogChannel(2,1);
AnalogChannel b2 = new AnalogChannel(2,2);

Compile, download, and run.
It will now fail (at runtime) saying Slot 2 Channel 1 is already allocated (or something like that).

Now comment out the following lines:

// AnalogChannel a5 = new AnalogChannel(1,5);
// AnalogChannel a6 = new AnalogChannel(1,6);
// AnalogChannel a7 = new AnalogChannel(1,7);

Compile, download, and run.

It will now work.

As far as I can tell (by trying different combinations), there seems to be a limitation on the TOTAL number of Analog Channels you can use!!!

If someone can try this code and let me know, I would really appreciate knowing if it is just something with our system, or if this is something everyone is facing.

Thanks!!

2

Yes, this is a bug in Java and C++ (artf1344 and artf1345) Thanks for finding it.

The result is that some channels for slot 2 conflict with channels in slot 1:

2,1 X 1,3
2,2 X 1,4
2,3 X 1,5
2,4 X 1,6
2,5 X 1,7
2,6 X 1,8

If you can deal with 10 or less channels then you can work around these conflicts.

3