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Glitch-Militia
Joined: Apr 25, 2011 Posts: 25 Location: Europe
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Posted: Tue Oct 08, 2013 12:20 pm Post subject:
BPM Counter w. 7 Segment LED Display |
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Is it possible to make a simple BPM counter with 7 segment LED displays, with CMOS? |
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JingleJoe
Joined: Nov 10, 2011 Posts: 878 Location: Lancashire, England
Audio files: 14
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Posted: Thu Oct 10, 2013 2:53 am Post subject:
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Right, so I'm assuming you have some kind of clock pulse which corresponds to a sequence, one pulse each step, then what you want to do is count how many pulses there are in one minute, but you don't want to wait a minute for that!
So count how many there are in say 3 seconds or 1 second if it's relatively fast, we'll call that Tc (time counted for). Then BPM = (60/Tc)*number of pulses counted.
To acheive counted pulses you could use a binary counter being driven by your clock pulses, this is what you could reset after Tc.
Say Tc = 3 seconds, then 60/3= 20, so you want to do some mathematics and multiply the binary number by 20.
Then you'd want to read that data just before it is erased (every 3 seconds in this case) store it in a shift register (like a 4006) and send that to a binary to 7 segment converter.
simple? maybe a little on the complex side but i can see how to do it within a second of reading your post so it can't be that hard
ICs you may find useful to look up: 4006, 4516, 40106 (for oscilators and timers and making your signals nice and square). I don't know any 7 seg display drivers but they are out there, there is the 4026 but that will be unsuitable for this operation unless you do something like send it a stream of pulses really quickly and that complicates things more so forget that one
If you're willing to wait a minute then you can just send your clock pulses to a counter which is stopped after 1 minute, then send the output of that to a binary to 7 segment display converter, you could even cascade a bunch of 4026s in that case. _________________ As a mad scientist I am ruled by the dictum of science: "I could be wrong about this but lets find out"
Green Dungeon Alchemist Laboratories |
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Glitch-Militia
Joined: Apr 25, 2011 Posts: 25 Location: Europe
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Posted: Thu Oct 10, 2013 4:38 am Post subject:
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Well it is complex for me atleast. Let's se how it goes. |
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JingleJoe
Joined: Nov 10, 2011 Posts: 878 Location: Lancashire, England
Audio files: 14
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Posted: Thu Oct 31, 2013 8:48 am Post subject:
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I thought of another way which could work from just two beats or rather, two pulses, there could technically be any time period between them.
It's a sort of frequency counter...
okay so to start, have a high frequency oscicllator, higher than your input beat frequency and some circuitry to turn it on and off or gate it between the start of two of your pulses (or beats). set this osicllator to a known number of pulses per minute and have it clock a counter.
e.g. if the high frequency osc is 60 per minute (one a second) and your input beat is 30 bpm (one every 2 seconds) it will clock the counter by 2 before it is turned off.
example #2 lets say your input frequency is 10bpm; then it will reset after 6 seconds and the counter will be at 6.
Now i know what you;re saying, this doesn't work or show the bpm! but you simply divide 60 by the number of the counter, you get 10 and 30!
probably has some kinks which need ironing out but it's a way to count bpm with just two beats.
Why don't you implement a bpm counter like this with a program? with a microcontroller? it'd be much easier. _________________ As a mad scientist I am ruled by the dictum of science: "I could be wrong about this but lets find out"
Green Dungeon Alchemist Laboratories |
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