Making a square wave which has two different kinds of pulse width

Question

I am going to make a square wave which has two different kinds of pulse width.At first,i think i can use the digital logic gate to finish it,however,after taking lots of time for trying,i still can't make it,so i come here to ask for help or suggestion.

The square wave i needed is as below

x and y means i don't care about its length,x can be bigger or smaller than y

Answer 1

Use two different timers and sum them together with a summing op amp:

^{simulate this circuit – Schematic created using CircuitLab}

Answer 2

You have multiple options:

• Using a timer, set a timer to the next time and change the GPIO value.
• Using PWM, and set a timer to change it at the next flank/up.
• Using a timer, and finding a 'common' multiplier, e.g. 1 us and check within the timer (interrupt) to change the GPIO or not. You can optionally use DMA.

Answer 3

Use a 16 MHz clock signal and feed it into a 4 bit binary counter. Then decode the outputs to give you a match to the output signal you want: -

Answer 4

This will do what you want.

^{simulate this circuit – Schematic created using CircuitLab}

While a 74161 is shown, 74LS/74HC/74HCT will all work.

If you step through the 16 possible output states of a 4-bit binary counter, you can verify the output logic.

For a 1 MHz clock, X will be 7 usec, and Y will be 4 usec.

And, just for extra credit, you can do all the output logic using a single 74/74LS/74HC/74HCT00 quad 2-input NAND gate.

And if you're actually going to use this in a logic circuit, you should feed the output through a D flip-flop triggered by the input clock to avoid skew glitches.

Answer 5

This is just my simple schematic,using two switch and two different kind of pulse width for each.

Schematic

Last wave is the output,the first and the second are the control voltage for each switch