savage
New Member
Hi,
I've got a coulpe of questions re best practises regarding getting IO from a PC... I've looked at the Parallell port, and I do know that I can get input from it as well, but I think that it is a tad to limited in regards to what I want.
For outputs, I've looked at Serial to Parallel Shift Registers (74HC595). I've linked them all, and now sit with about 32 of these chips for 256 ouputs - all used for signals. Now, about the outputs...
The 74HC595 isn't IMHO exactly cheap. Around here, I pay about US$1.20 per chip. Is there a cheaper alternatives? Also, are there possibilities that I can use to decrease the amount of ICs on the board? Say, have something like 2 x 595's integrated into a single chip... Or 4 of them, or ... You get the idea...
Then, I'm a little baffled as to my inputs. I'll require more than double the amounts of input than output - by far. Just one small section of the project has over 100 switches that I need to monitor, and I need to know when the switch is on or off, and when that switched was turned on (or attempted to be turned on).
My first idea was to just use Parallell to Serial shift registers again (74HC959 this time). This is a problem mainly because of the sheer size of the amout of ICs required to get all my inputs. Add to that the ICs for my outputs, and at the end of the day... Well, I personally don't feel like soldering 100+ 16p DINs into a PC Board...
Then I thought of a keyboard perhaps, using either the PS2 or AT socket on a PC. Again, a keyboard simply just do not have enough buttons to simulate all the inputs that I require Best case scenario would more than likely be some sort of key matrix mapping for my inputs, but up to now, I'm yet to find anything that is easily available and big enough to accommodate the sheer amount of inputs that I required.
Whilst the outputs are fine (except for the cost factor maybe and the amount of chips required)... What can I possibly do in regards to inputs?
I'd prefer to stay away from PICs and Microcontrollers, as I lack the knowledge to program them. If I don't have a choice in the matter (which I don't think I have), then I guess it's time to dive into the deep end again and learn..
Thanks, look forward to replies and suggestions.
--
Chris
I've got a coulpe of questions re best practises regarding getting IO from a PC... I've looked at the Parallell port, and I do know that I can get input from it as well, but I think that it is a tad to limited in regards to what I want.
For outputs, I've looked at Serial to Parallel Shift Registers (74HC595). I've linked them all, and now sit with about 32 of these chips for 256 ouputs - all used for signals. Now, about the outputs...
The 74HC595 isn't IMHO exactly cheap. Around here, I pay about US$1.20 per chip. Is there a cheaper alternatives? Also, are there possibilities that I can use to decrease the amount of ICs on the board? Say, have something like 2 x 595's integrated into a single chip... Or 4 of them, or ... You get the idea...
Then, I'm a little baffled as to my inputs. I'll require more than double the amounts of input than output - by far. Just one small section of the project has over 100 switches that I need to monitor, and I need to know when the switch is on or off, and when that switched was turned on (or attempted to be turned on).
My first idea was to just use Parallell to Serial shift registers again (74HC959 this time). This is a problem mainly because of the sheer size of the amout of ICs required to get all my inputs. Add to that the ICs for my outputs, and at the end of the day... Well, I personally don't feel like soldering 100+ 16p DINs into a PC Board...
Then I thought of a keyboard perhaps, using either the PS2 or AT socket on a PC. Again, a keyboard simply just do not have enough buttons to simulate all the inputs that I require Best case scenario would more than likely be some sort of key matrix mapping for my inputs, but up to now, I'm yet to find anything that is easily available and big enough to accommodate the sheer amount of inputs that I required.
Whilst the outputs are fine (except for the cost factor maybe and the amount of chips required)... What can I possibly do in regards to inputs?
I'd prefer to stay away from PICs and Microcontrollers, as I lack the knowledge to program them. If I don't have a choice in the matter (which I don't think I have), then I guess it's time to dive into the deep end again and learn..
Thanks, look forward to replies and suggestions.
--
Chris