I am developing a ranging device to help people with blindness. I need to pulse a 38 kHz Infrared LED every 1 second. A 555 timer in astable mode generates the 38 kHz modulation. I'm currently using two ICs, one to blink every second and another that constantly generates the 38 kHz modulation. However, I feel it may be possible to do it with a single 555 IC. Because the reset pin of the 555 turns off the oscillation whenever it is grounded, I thought it might be possible to use a capacitor and resistor combination to pulse the reset pin every 1 second. Perhaps there is a different combination of doing this without using an additional IC?
The current configuration is a basic 555 astable oscillator as below. I'd prefer to add simple components to the reset pin that would allow me to control the duty cycle of when the 38 kHz signal is triggered without using an additional IC.
R1 = 4.7k R2 = 22k C1 = 680 pF