Pulse Reader Component

[Ganz]

Hello everyone,

I'm using a microcontroller that just doesn't have enough pins. I know I could get a bigger one but I was wondering if there were any other solutions.
I am running a few LED bulbs as well as a LCD numeric 4 digit display.

I don't know if this exists but I was hoping there was a component that reads a pulse and then based on that pulse, sets one of the output pins high. So say the microcontroller sends out a pulse of 100 kHz, then the component would read that pulse and know to output a high voltage to a certain pin (which I would connect my LED bulbs to so I could consolidate pins).
If something like that exists, I would love to know about it.

If you have any other suggestions to consolidate pins, please let me know.

 

[jpanhalt]

If I understand your question, you want to send different frequencies from a single pin and have each frequency turn on a different LED or other action.

An easy way would be to use an LM567 tone decoder, which were used in old telephones (https://www.ti.com/lit/ds/symlink/lm567.pdf). Reed relays, which were tuned to different frequencies, were also used. You might have a hard time finding them today.

My first choice, though, would be a chip with more port pins, particularly since you already are using an mcu.

John

 

[alec_t]

You could perhaps use one pin to clock a CD4017 counter and a second pin to reset the counter. That would give you ten outputs (albeit usable only one at a time without additional latches) for the price of 2 pins. Of course you would have to whip through the unwanted outputs before getting to the wanted output, but simple low-pass filtering could overcome any undesirable effect of that.

 

[Ganz]

If I understand your question, you want to send different frequencies from a single pin and have each frequency turn on a different LED or other action.

An easy way would be to use an LM567 tone decoder, which were used in old telephones (https://www.ti.com/lit/ds/symlink/lm567.pdf). Reed relays, which were tuned to different frequencies, were also used. You might have a hard time finding them today.

My first choice, though, would be a chip with more port pins, particularly since you already are using an mcu.

John

Is there a microcontroller that you recommend? I am using the atmega16m1-au. Basically I want an upgrade from this that has more pins.

 

[dr pepper]

How about a 4094 shift register.

 

[alec_t]

.... or you could control 8 outputs using 4 pins and a 74HC238 (3-to-8 line decoder).

 

[Joe G]

well, how bout running 2 leds with 1 pin, kind of like "charlie plexxing" . don't know much of how many you are using? Check it out on WIKIPEDIA