Code to Read the Binary Inputs on Analog Buttons

Technical Control System
1

Does anyone have example code on how to read the binary digits from the OIs analog inputs? According to Mike only the first 4 binary digits are used to determine buttons being pressed.

For Example:

1000 0000 = Button 1
0100 0000 = Button 2
0010 0000 = BUtton 3
0001 0000 = Button 4

The trouble is the last four digits are random and fluctuate greatly
depending on what mood the chicklet is in so sometimes

1000 0000 = Button 1
or
1000 0001 = Button 1
or
1000 0010 = Button 1

The problem is we really don’t want to make 4 cases for every button.
So we just want to ignore them.

2

The important thing is to use the bitwise AND function in C (&). That’s what it’s designed for.

Make a set of global variables, and a function that you call every time through the loop that sets these variables from the OI state.

Something like this should work (and I’ve gotta love any chance I have to legitimately use C’ ?: trinary operator) :


int p1_sw_5,p1_sw_6,p1_sw_7,p1_sw_8; // Virtual buttons

void Buttons(void)
{
   p1_sw_5=(p1_aux&1<<7)?0:1;
   p1_sw_6=(p1_aux&1<<6)?0:1;
   p1_sw_7=(p1_aux&1<<5)?0:1;
   p1_sw_8=(p1_aux&1<<4)?0:1;
}
3

Nice, never used that before :slight_smile:

4

now correct me if im wrong but isnt your use of the ? operator the same as the ! operator

im pretty sure that

p1_sw_5 = !(p1_aux&1<<7);
will do the same as
p1_sw_5=(p1_aux&1<<7)?0:1;

5

the “(statement)?true:false” syntax is like an if statement in one line
if statement, then true, else false

in this case, however, it would do the same

6

You are correct.

7