EC11 rotary encoder no push button
what do we need
1x ATTINY45
2x 4K7
1x 10K
1x EC11

We have 2 options for the connection to the main MCU

with 2 outputs
1x pulse output when turning right
1x pulse output when turning left
The ATTINY45 provides 20 millisecond pulses on either the right turn output or the left turn output.

or with 1 output
1x output
The ATTINY45 delivers
10 millisecond pulses when turning clockwise
20 millisecond pulses when turning counterclockwise
and this on the same output.

Thanks to

https://www.elektormagazine.nl/labs/rotary-encoder-on-a-single-mcu-pin

for the 1 input idea


EC11 rotary encoder push button
what do we need
1x ATTINY84
3x 4K7
1x 10K
1x EC11 with push button

with 2 outputs
1x pulse output when turning right
1x pulse output when turning left
The ATTINY84 provides 20 millisecond pulses on either the right turn output or the left turn output.
Push button must be connected separately to main MCU

with 1 output
The ATTINY84 delivers
10 milliseconds pulses when turning clockwise
20 milliseconds pulses when turning counterclockwise
30 milliseconds pulse when push button is pressed
and this on the same digital output

Further specifications
power supply 3.3V or 5V
no extra capacitors or resistors
no libraries
works for slow and fast rotation
cheap about 3€
easy to build

ATTINY45 program and ESP32 program for 2 inputs or 1 input in .pdf file

https://github.com/thieu-b55/EC11-rotary-encoder-the-easy-way