| ??? 09/12/10 11:38 Read: times |
#178517 - Start by specify your need Responding to: ???'s previous message |
You start with just mentioning controlling of nearly 450 pins. This is trivial to do with a latched shift register chain since you only require 450ms response times.
But way down in your text yu suddenly mentions "in the form of analog voltage". Suddenly you need DAC or PWM capabilities - there are externa PWM chips available. But you really have to list down the full requirements for your pins before it is meaningful for us to spend any time on your problem. It isn't even meaningful for you to spend time on the problem if you don't know what the 450 pins are expected to do. If they are digital inputs. Or digital outputs. Or analog inputs. Or analog outputs. Or counter inputs. Or capture/match inputs. Or square wave outputs. Or ... |
| Topic | Author | Date |
| I/O pin extension | 01/01/70 00:00 | |
| Start by specify your need | 01/01/70 00:00 | |
| you really have to list down the full requirements | 01/01/70 00:00 | |
| A suggestion | 01/01/70 00:00 | |
| Specefic Requirements | 01/01/70 00:00 | |
| Why relays? | 01/01/70 00:00 | |
| But dot matrix printers normally don't have X*Y array head | 01/01/70 00:00 | |
| Only need *one* column of dots! [ED] | 01/01/70 00:00 | |
| Head has constant speed w/o steps even with stepper motors | 01/01/70 00:00 | |
| reply | 01/01/70 00:00 | |
| not helpful! | 01/01/70 00:00 | |
| Necessity of relays | 01/01/70 00:00 | |
| Relays are not necessary | 01/01/70 00:00 | |
| What's a "design"? | 01/01/70 00:00 | |
| Discrete or integrated | 01/01/70 00:00 | |
| So what's the reason for a slow ctar-at-a-time head? | 01/01/70 00:00 | |
| Printer Purpose | 01/01/70 00:00 | |
| Still no specific reason for a matrix! [Ed] | 01/01/70 00:00 | |
| More care while finding solution | 01/01/70 00:00 | |
| RE: "many others" | 01/01/70 00:00 | |
| Smaller than a relay | 01/01/70 00:00 | |
Relays Take Drivers Too | 01/01/70 00:00 |