Using rotary switch with a PIC16F877

[abdullahbicen]

I want to use 1 pole-12 ways rotary switch with a pic16f877 in my project. My problem is switch has a lot of pins and I don't want to use pic's pins in order to read switch's position. Is there another way of doing this?

 

[laktronics]

Re: rotary switch

Hi,
Use two numbers of 74HC148 in cascade.
Regards,

 

[Mike K8LH]

Re: rotary switch

Or use a rotary encoder (requires 2 pins for the A and B encoder outputs)...

Mike

 

[arbj]

rotary switch

you could also use the ADC port
Connect the ADC port to a potentiometer, (center to adc port, max end to +5V and min end to GND)

Since you need 12 positions, each position change occur at intervals of 30 degrees.

or 1023/12= 85 bits (approx)

To get the position number, divide the ADC value (10 bit data) by 85, the result obtained (without approximation) will be the position selected.

arb

 

[art-666]

rotary switch

If you want to use Switch use 12 resitors and the ADC port

 

[abdullahbicen]

Re: Thank you all

Thanks for your help. I am planning to use two 74ls148. Since I am new to pcb design, I am not sure to use digital and analog parts on the same pcb.

 

[arbj]

rotary switch

you can use both