Help on how to make digital inputs into Joystick position

[damaxx]

Looking to use 10 digital inputs to give an analog value for a the X axis of a game controller.
So rather than a true analog input, it will be 10 or 11 stepped positions from the digital inputs.


The digital truth table looks like this -

0 1 2 3 4 5 6 7 8 9 Analog
1 0 0 0 0 0 0 0 0 0 1023
1 1 0 0 0 0 0 0 0 0 921
0 1 1 0 0 0 0 0 0 0 819
0 0 1 1 0 0 0 0 0 0 717
0 0 0 1 1 0 0 0 0 0 615
0 0 0 0 1 1 0 0 0 0 513
0 0 0 0 0 1 1 0 0 0 411
0 0 0 0 0 0 1 1 0 0 309
0 0 0 0 0 0 0 1 1 0 207
0 0 0 0 0 0 0 0 1 1 105
0 0 0 0 0 0 0 0 0 1 0

So pretty straight forward.
I just need to put that value into Joystick.X(value); and I am unsure of the cleanest way to do it.

Very new to coding so I would appreciate fairly basic answers if possible although any help would be appreciated.

 

[stevech]

looks like a grey code of sorts- meaning only one bit changes value from adjacent rows in that truth table.
If you're not counting microseconds speeds, and don't want to do a table-lookup... then I'd just code a C case statement

// ordinary C code:
int n, tenBitValue;
// get input into: tenBitValue, then 

switch (tenBitValue)  {
[INDENT]case 0x200: n = 1023; break;
case 0x300: n = 921; break;
case 0x180: n = 819; break;
etc
case 0x003: n = 105; break;
case 0x001: n = 0; break;
default: n = -1; [/INDENT]
}
// now use the value stored in variable: n (if n is not -1)

This code assumes the truth table and bits of I/O come in as listed in the table. NOTE: the bit numbers in the truth table's column headings are reversed from computer conventions, where the least significant bit is number 0, next is number 1, etc. I think of the bit numbers as the exponent of the powers of two, where bit 0 is 2 to the 0th = 1, bit 1 is two to the first = 2, etc.

the numbers above, like 0x300, are hexadecimal. 0x100 = 512 decimal (two to the 8th power). Each digit in hexadecimal is 0 to 9 or A to F, standing for the values 0 to 15 decimal. Hexadecimal is just groups of four binary bits, where four bits span 0 to 15 decimal. Your table has binary bits (0 or 1). Some compilers support the non-standard notation of 0b11001101 etc where the '0b' means the rest of the digits are binary as is your table. But not good to use '0b' as it's non-standard for C compilers.

 

[damaxx]

Thanks so much for that reply Steve. That makes total sense. I appreciate the detailed explanation.