4040 12-bit Counter

[Olakunle]

Dear sir,
 I want to read a frequency counter values with visual basic.
I need 1s i.e 1hz from a 4mhz crystal and I have 2 4040 12-bit counters.
I can divide each counter by 4096. The problem is that I need to divide one
4040 by 4000 and the other by 1000 to get 1s.How should I divide by 4000 and 1000
using AND Gates etc with the Counters?

[Jan Axelson]

I would capture the information with a microcontroller circuit and send the data to Windows via USB, serial, or another interface. Windows isn't the best solution for reading real-time data.

Jan 

[mdlayt]

This sounds like someones homework assignment.

I'm not sure what visual basic has to do with it, and I haven't looked at the data sheets for your counters, but based on what you said, I think you need to:

Figure out what the binary values are, create karnaugh maps for them, decode them with your "and gates, etc." and use that to (hopefully) synchronously reload your counters.

[Stefke35]

This sounds like someones homework assignment.

I'm not sure what visual basic has to do with it, and I haven't looked at the data sheets for your counters, but based on what you said, I think you need to:

Figure out what the binary values are, create karnaugh maps for them, decode them with your "and gates, etc." and use that to (hopefully) synchronously reload your counters.

Use C++ or MFC, PowerBasic they do the tasks perfectly

[Barry Twycross]

I just remembered I actually implemented something similar to this a long time ago (like in 1984), I'm pretty sure it was actually using 4040 counters.

The basic trick is to get it to count up to the number you're interested in, then arrange for a circuit to pull on the MR (master reset) input. It then starts counting again from 0. That input then also feeds the next stage clock.

The circuit to recognise the particular output value is where the intesting bit is. I had an arbitrary 4 bit input as one set of inputs to a 4 bit comparator like the 4063. The slow 4 clock output bits were the other set of inputs. As you have a fixed input, it'd be pretty simple to do the same thing with NOT and AND gates. NOT the bits which you want low and AND all the bits to produce the reset output.

Dividing by 2000 twice (rather than 4000 and 1000) might be simpler, you just have to repeat one circuit design.

[Jan Axelson]

I think I once had a toaster that had a 4040 counter in it...