Heart Beat Counter Circuit

Should you still be teaching clocks, gates, counter etc when they are not used in applications like this assignment? Is this is history class? That wont teach you how to use micro's and debug the code. Unless lesson assignment #2 is to do the same project with a micro.

My apologies to the OP for not providing an answer appropriate to the question, but I quit doing any hardware logic over 10 years ago.

Luhan

On a sunny day (11 Dec 2006 06:47:57 -0800) it happened "Luhan" wrote in :

It is hardware logic all over again in FPGA these days. Although it is the difficult route, I think Altera has the 7400 series as HDL modules.

My error. I went from hardware logic design to 8080/Z80/68000/8748/PIC but never made the jump to FPGA. (still have not personally had any need for them).

Luhan

Rachel, this is cheating! Im reporting you...just kidding, please share anything you find out.

Thanks, Dan

On a sunny day (11 Dec 2006 07:27:25 -0800) it happened "Luhan" wrote in :

There are a few things where FPGA makes sense, speed is one of these. The other thing is that you can do things in parallel. The third is perhaps the incredible amount of IO pins and standards supported. The drawback is price, and the incredible amount of IO pins :-) (that then translate to ballgrid packages). There are more thing of course. Yes I went the same path, but left out the 68000, did other processors, but still have a 68000 laying about somewhere :-)

I'll let ya know if I get anything useful!.....

Rachel

--- Yeah. JK's or D's, but they're wired to output a pulse when they overflow from 9 to 0 if they're counting up, and that pulse can be used in a variety of ways to get the next counter upstream to increment. Or for other stuff.

I found a neat way to do the multiply-by-four and I'll email you a copy of the schematic as well as post it to abse with your schematics so those interested can see it as well.

It'll be an hour or so...

-- JF

I once worked with a system that used digital filters to recognize a QRS, and just counted microseconds from one to the next and divided (to go from rep time to rep rate; scaled, of course. :-) )

I think they kept a running average, so the rate didn't change abruptly if there was variation in the time from one beat to the next. Even with that, the display was more like real-time than what you're suggesting.

However, if you're locked in, here are a couple of answers:

To reset the counter, you just need a timer/counter that issues a "reset" pulse every 60 seconds.

To connect the counter to a display, you need a binary/BCD converter, and 7-segment decoder/drivers, and the displays.

Good Luck! Rich

I meant the 45 that comes after the 15, that'd work.

I can't say for sure but I suspect there's marks given for meating the specification exactly, so if you add features not in the specification (like background counting) you'd better make them switchable.

the multiply by four can be done using a monostable that turns on an astable long enough to let 4 pulses out.

Bye. Jasen