My multiplexers from Futurlec arrived today! I went with the SN74150N a link to the datasheet is below. This is the first time I have ever interfaced with an IC. I don't really have any specific questions. I guess I'm just looking for some good direction to help me get started. the forum posts I have read I'm sure will be helpful once I get going but are not about this specific chip. I'm a bit overwhelmed! My goal in the end is to be able to read from 16+ Pots. Thanks in advanced.
I haven't used a multiplexer myself, but basically you put a binary number from 0 to 15 into pins A B C D to select the complement (inverted) signal on the E line it addresses.
A appears to be the LSB and D the MSB, so:
A B C D 0 0 1 0
decimal 2, would select E2 (pin 6), and the inverted signal present on E2 would appear on the output, W.
A B C D 1 1 1 1
would select E15, and so on.
The easiest way to interface with the chip is to use 4 digital pins on the Arduino.
Hope this helps.
MAKE SURE YOU ARE AWARE THAT THE OUTPUT SIGNAL IS INVERTED.
also you will probably want to hold the STROBE/ENABLE pin (9) low. When this pin is high it forces the output high.
Does the chip work with analogue signals? If you want to read pots it'll have to.
If it doesn't I can think of a way to just use a 4:16 multiplexer and scan through each pot individually
hmm many multiplexers would handle analog signals 0-5V but without checking the data sheet again, I'd have to say its for digital signals only because of it's inverted output (why the heck would you want analog signals "inverted"?)
The 74150 is a digital multiplexer, it won’t work with analogue signals at all, sorry.
For an analogue multiplexer you need a 4067 if you want to read the value from pots.
Oh well, I'm sure you'll find something to do with that chip sometime. Too bad it isn't what you were looking for.
I agree, the 4067 suits your purpose.
(why the heck would you want analog signals "inverted"?)
Lots of reasons, if you were applying negative feedback or wanted a signal cancelling circuit for a start.
Well that sucks that I got the wrong Components. Can someone explain how I can tell if its Digital or Analog the datasheet doesn't mention the words digital or analog on the entire thing.
NKCelectronics has a breakout board with the CD74HC4067 IC on it.
It will allow you to interface 16 analog or digital inputs.
It's so cheap ( 4.95 $) that it's hardly worth the effort to try to make one your self. You could stack two of them on top of each other and have 32 analog ins.
Can someone explain how I can tell if its Digital or Analog the datasheet doesn't mention the words digital or analog on the entire thing.
At first I thought no but when I looked at it you are right.
However, it does talk about logic levels and they are only digital, it does talk about TTL levels and they are only digital. The problem is that it is so obviously digital no one mentions it specifically because the only data switch, when this came out, was a digital one. The whole 74 series of ICs are digital only, it known as digital logic. I think it is a case of it being so obvious as it is not worth mentioning, rather like the statement "water is wet". But I agree for a beginner it is not obvious so sorry, you will have to chalk that one down to experience.