R
rishi
Guest
Thanks alot Dear Mac
See what i was thinking :
S1,1 | S10,1 |
--|---------------------|--- R1
S1,2 --|---------------------|--- R2
| | |
| | |
| | |
S1,50--|---------------------|--- R50
| S10,50|
C1 C10
lines(writing 1 to each column and tristating other 9
lines) , and read back R1 to R50 to get the state of
all the switches in a column.
I am thinking using optocouplers at the ends and using
higher voltages(24 or 48VDC) for the matrix itself
instead of 5 V.Will this reduce the problems of noise?
I think i can scan at much higher rates maybe 100~150 HZ.
Will there be any problems of propogation delays?
I will be requiring a PCI card with 64 IOs only.
Thanks alot can you please suggest me.
Best Regards
Rishi Bhanot
See what i was thinking :
S1,1 | S10,1 |
--|---------------------|--- R1
S1,2 --|---------------------|--- R2
| | |
| | |
| | |
S1,50--|---------------------|--- R50
| S10,50|
C1 C10
I said 60 IO lines as i would use C1 to C10 as outputWhat I don't understand is how you plan to multiplex your 60 IO lines into
500 (or 1000?) switches. Is that where you would use the bus receivers? I
guess it could work. Logically you have 10 banks of 50-line bus receivers.
In reality, each bank may be more than one chip. The banks are all
connected together, and at any given time, only one bank is active,
and the others are disabled with their drivers in a high impedance state.
The 10 remaining lines on your IO board can be configured as outputs, and
each one can select one of the banks.
The other option is trying to find an IO board with 500 IO's on it.
lines(writing 1 to each column and tristating other 9
lines) , and read back R1 to R50 to get the state of
all the switches in a column.
I am thinking using optocouplers at the ends and using
higher voltages(24 or 48VDC) for the matrix itself
instead of 5 V.Will this reduce the problems of noise?
I think i can scan at much higher rates maybe 100~150 HZ.
Will there be any problems of propogation delays?
I will be requiring a PCI card with 64 IOs only.
Thanks alot can you please suggest me.
Best Regards
Rishi Bhanot