Need help with Light Metronome

Thread Starter

tobman

Joined Feb 21, 2010
26
I was told to build a working model of metronome that may be used by a group of musicians. The metronome will have different coloured lights of certain beats in the bar. The most important beats is the first beat and will have a bright light. The following colours are required

beats light
2 white, red
3 white red, red
4a white, red, red,red
4b white, red, yellow,red
5 white, red, red,yellow,red
6 white, red, red,yellow,red, red
7 white, red, red, red, yellow,red, red

i just need the circuit diagrams and suggestion please. I will be glad if anyone can help bcos its an important project.
 

retched

Joined Dec 5, 2009
5,207
Do you want it to count and light like:

1 and a 2 and a 3 and a 4 and a

the numbers (1234) would be a white led the 'and's would be red and the 'a's would be yellow
For counting the half and quarter notes.

Is that what you mean?
 

Thread Starter

tobman

Joined Feb 21, 2010
26
Thanks for the response.

What i want is, when a 2 beats is selected i just want 'white' and 'red' to be flashin continously

when a 3 beats is selected i want 'white' 'red' 'red'
when a 4a beats is selected i want 'white' 'red' 'red' 'red'
when a 4b beats is selected i want 'white' 'red' 'yellow' 'red' and so on. Thanks
 

retched

Joined Dec 5, 2009
5,207
Ok. We need to determine the values that we want to display. the max and min.

How many beats per minute will the metronome show?

Are you comfortable with using mircocontrollers or do you want to stick with discretes and standard ICs?


For each value (ie. 120bpm) you would want to divide it by the number of lights. Then display each light for that amount of time.

So 120bpm with white and red, (2 leds) will show the white for half the time than the red for the other half for each beat.

3 leds:
120bpm white for a third of the time red for a third and anothercolor for a third of each beat.

then so on..
 

Thread Starter

tobman

Joined Feb 21, 2010
26
THANKS FOR YOUR REPLY

i wiould like to stick with standard ic's and discretes. The tempo should be able to vary. Thanks
 

retched

Joined Dec 5, 2009
5,207
Yes, I know you want it to vary, but from what to what? Using a 555 timer chip, we will need to use resistors to get each tempo setting, so we need to know the smallest and largest values needed for the timer. Standard metronomes use 40 to 208 beats per min for their scale.. Shall we use the same?
 

retched

Joined Dec 5, 2009
5,207
So we are going to have eight modes correct?
8 ways to count each of the 168 bpm selections.

do you want 3 leds :
(white) (red) (yellow)
or 7 leds:
(white) (red) (red) (red) (yellow) (red) (red)

So 40 bpm will have
White only
white then red
white red, red
white, red, red,red
white, red, yellow,red
white, red, red,yellow,red
white, red, red,yellow,red, red
white, red, red, red, yellow,red, red
 

Thread Starter

tobman

Joined Feb 21, 2010
26
yeah, could it be possible to have it with just three lights (white, red, yellow). when we need a red to repeat itself (like in your illustration), we could just have it blink twice or thrice as the case may be.
 

retched

Joined Dec 5, 2009
5,207
What will the red and yellow signify? Typically a metronome blinks brightest for the 1 and dimmer for the 2 3 4. I could see the 2 color the white on the 1 and red on 2 3 4. Are you wanting the yellow and red to be off beats? or syncopated beats? And the white being the 1 beat? I will need to know to know when to trigger each event through the cycle.
 

Thread Starter

tobman

Joined Feb 21, 2010
26
thanks for replying in short notice.
lets say for example: for a 4 beat of 4 bars, we going to have white, red, red, red (red blinking thrice). and for a seven bar, we're going to have white, red, red,red, yellow, red, red (notice the red blinking thrice and then twice after he yellow) so its like we have a four included in a seven.
so in a four, the three red are the dimmer lights signifying 2, 3, 4 while the white light should be the first beat.
 

retched

Joined Dec 5, 2009
5,207
So you want the metronome to display in time signatures. Ok..this isn't going to be easy without a uC.

You will need to select which one of the eight operation modes you want, and which one of the 168 different BPMs to display at.
 
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Thread Starter

tobman

Joined Feb 21, 2010
26
yea i guess so, so what do you think using a μc is going 2 imply, and also i would want to know if u have any easier option.
thanks
 

retched

Joined Dec 5, 2009
5,207
Im trying to think of the logic. If it was the same pattern, it wouldnt be to bad. we could reset it where we wanted.. but 4b and 7 have me pulling my hair out.

If the pattern for all was

W R R R Y R R

for choice #1 we could go 2 steps ( W, R) then reset (W, R) over and over
for 2 it would go 3 steps then reset ( W, R, R) reset ( W, R, R) over.
for 3 (W, R, R, R) (W, R , R ,R)
for 4 (W, R, R, R, Y) RESET (W, R, R, R, Y)
Now 4b screws it up (W, R, R, yellow) where in a logical order it would be red.
because the third red is a yellow in this. so we cant use the same pattern(array)
 

Thread Starter

tobman

Joined Feb 21, 2010
26
yea, i think we should try it that way. if we were to go with that logical option, what do you think we should do (if these lights going to blink).
 

retched

Joined Dec 5, 2009
5,207
Well with an uC we could do it the way you want. But without, at least at my knowledge level, I would not be able to show 4b or 7 properly.

for the rest, Use a 555 with a variable resistor to set the bpm level. Then using a shift register, send a 11111110 to it. This will say lamp 1on 2on 3on 4on 5on 6on 7on
For which mode, we can reset the shift register at the points I spoke of earlier.
So for the 1st mode, at 40 bpm, reset after 2 counts
it will show:
White light, red light. And loop continously .

and so on
 

Thread Starter

tobman

Joined Feb 21, 2010
26
is it possible to draw the schematics with explanations so i can have a better understanding.
and also, do you think there was any way we could have adjusted the lighting arrangement for the 4b and 7 so they could fit in?
thanks for all the responses
 
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