Turn CD4029 on/off with TTP223

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ThomsCircuit

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This circuit cycles a set of LEDs (red green and blue) in series (24 total leds)
12v power source with a 5v regulator for the TTP223 IC

A member helped me add this feature to this LED cycle circuit where a touch from TTP223 will take pin4 (reset) of the 555 from a high (4Volts) to low (short to ground) thus allowing the 4029 to begin counting and illuminating the LEDs in a pattern.
While initially when power is first applied it does work. The 4029 is not counting so no led sequence. After a touch pin4 of the 555 is taken from high to low and the 4029 begins its cycle but if you touch the TTP223 again to stop the process it does not turn off what ever leds happen to be lit at the time. It simply pauses. What could be done to also turn off the leds after the TTP223 goes high then turn back on when it goes low again.
Thank you.
 
Hi

You can insert (CD4081B) AND gates between the output of the CD4029 and the resistors. There is four gates in a CD4081B chip. One gate won't be used. If the 555 reset is low, the clock stops, the transistor inputs will be disabled, and the lights will be off. If the 555 reset is high, the clock runs and the transistor inputs are enabled. See below.

 
Thank you E. I completely understand this. Ill get the part on my next order.
Ive finished making my own RGB LEDs with no common (6pin) They look great and the diffusion from the epoxy gives them a 100% viewing angle.
 
You could add a PNP transistor to force the PE input of the 4029 high when the 555 is reset. You would need a base resistor for the transistor, and a resistor to stop the Q4 output of the 4029 being overloaded when the reset is happening.


Alternatively, you could use just one gate from a 4071 quad OR gate to do the same thing. The two inputs of the OR gate would be the reset of the 555, and Q4 of the 4029. The output of the OR gate would drive the PE input of the 4029.

Those schemes would reset the 4029 to a count of zero, while eTech's suggestion would leave the count at it's last value, but it's not a noticeable difference.
 
Diver300 said:
You could add a PNP transistor to force the PE input of the 4029 high when the 555 is reset.
Click to expand...
What an awesome suggestion. I have the 3904's complementary PNP 3906 and also a number of 327's. I could easily add this right in without ordering additional components.

Q: I want to measure the voltage output of the TIP122's with my DMM
Would I probe the emitter and ground to do this?
 
Note that the two answers are not equivalent.

With the AND gate approach, after the third touch the circuit will pick up where it left off in the pattern. IOW, after the second touch the LEDs are disabled, but the counter is not reset to 0.

With the OR gate approach, the LED drivers still are active, but the counter is reset to zero.

ak
 
ThomsCircuit said:
Q: I want to measure the voltage output of the TIP122's with my DMM
Would I probe the emitter and ground to do this?
Click to expand...
Yes.

I also noticed that the circuit diagram doesn't show the grounds connected together. All the grounds, shown in green, should be connected together.
 
Not sure why 4029 reset is of concern. The 4029 is basically a pseudo random pattern generator.
 
eTech said:
The 4029 is basically a pseudo random pattern generator.
Click to expand...
Really? It looks like a rigidly binary pattern generator to me.

The OP doesn't say what this is for, so repeatability of the initial condition may or may not be important.

ak
 
Diver300 said:
I also noticed that the circuit diagram doesn't show the grounds connected together.
Click to expand...
Are you referring to that lone ground at the top left? Im always exploring alternate ways of displaying my input pins. I must confess this was not the best approach. It is meant for the purpose as shown in this image.
 
AnalogKid said:
Really? It looks like a rigidly binary pattern generator to me.
The OP doesn't say what this is for, so repeatability of the initial condition may or may not be important.
ak
Click to expand...
You correct. It is not important if the counter resets or not. Just as long as the LEDS go out OR on when the USER touches the metal ring. The purpose of this circuit is purely decorative.
 
This is a round box that mounts to the center of a frosted glass table.
For the guests sitting around the table the table appears flush with only a metal ring protruding from the center.
The bulk of the box and the 8 RGB LEDS are beneath the glass table top.
It is simply for entertainment. An upgrade from the boring (and broken) dim amber LEDS it once was.

The box has been modified to contain this circuit that drives the LEDS, a round circuit board that holds the LEDS, and a feedback circuit that produces a beep from a peizo speaker when the USER interacts with the metal ring. The ring was originally painted black but has been polished to serve as the TOUCH switch



RGB LEDS
3 water clear leds encased in epoxy then polished.
 
Last edited:
eTech said:
Yes…but when operating the lighting pattern appears random..
Click to expand...
Only for a low number of cycles. There is a difference between pattern recognition and recognizing that there is a pattern. Pattern recognition is the stuff of Mensa quizzes and code breaking. Recognizing merely that there is some kind of repeating pattern is way easier. Over 90% of people discern a small, random repeating pattern in 6 cycles or fewer. For a binary pattern it is even less because the big transition from on-on-on to off-off-off is hard to miss. Suppressing the zero state makes the binary pattern closer to a truly random pattern in discernment difficulty.

Of course, the number of cycles needed to recognize that there is something repeating going on increases with the pattern size (number of steps in a cycle) complexity (number of items in a step).

Back in the 80's I designed research lab equipment for several departments at a large university. Learned all kinds of random goop. One of the departments was Psych, the experimental (now "cognitive") and social areas. I did several pattern generators, some for recognition, masking and noise, cognitive loading, etc. As more and more labs got IBM pcs, I shifted to short BASIC programs to create the patterns, and used the parallel printer port for I/O.

ak
 
ThomsCircuit said:
Are you referring to that lone ground at the top left? Im always exploring alternate ways of displaying my input pins. I must confess this was not the best approach. It is meant for the purpose as shown in this image.
View attachment 137767
Click to expand...
I hadn't seen the layout. I just wanted to point out that the grounds all have to be connected together, and the circuit diagram doesn't make it clear if they are or not.
 
I think your reading too much into my reply. Technically it is a sequence, optically it appears random. But thanks for the history.
 
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