??? 04/23/05 13:06 Read: times |
#92231 - It is possible to do but why..... Responding to: ???'s previous message |
The analogue scheme to encode multiple switches into a single wire is possible...but in my book a waste of time. I can say that I have seen it done in products but I have heard about many problems of reliability for those same products. The required circuitry alone makes it hard to get working and the result is still a pain in the behind to get a stable result.
For local switches which are near to the microcontroller a much better result can be had with using a matrix connected to port pins. If there is a shortage of I/O pins then get more....easy solution these days. The best additional I/O can be attained through use of a small microcontroller running as a slave device. Interface via some serial technique using UART, I2C, SPI etc. If the switches are remote then the serial technique lends itself directly !! If isolation is really required it is easier to isolate a single serial line than a whole bank of switches. Michael Karas |
Topic | Author | Date |
ADC as digital input | 01/01/70 00:00 | |
Saturation | 01/01/70 00:00 | |
good point | 01/01/70 00:00 | |
URL | 01/01/70 00:00 | |
all good, but | 01/01/70 00:00 | |
optocouplers | 01/01/70 00:00 | |
Re: ADC as digital input | 01/01/70 00:00 | |
go analog | 01/01/70 00:00 | |
schematic | 01/01/70 00:00 | |
It is possible to do but why..... | 01/01/70 00:00 | |
opto | 01/01/70 00:00 | |
Possible but troublesome... | 01/01/70 00:00 | |
very informative | 01/01/70 00:00 | |
overcomming opto difference![]() | 01/01/70 00:00 |