Python module for the KY040 rotary encoder.
GPL-3.0 License
Version: 0.2.4
This module has been developed for quickly interface a rotary encoder with Raspberry Pi. It's based on the pigpio library (cause it proved to be faster than rpi.GPIO or gpiozero libraries) so you need to install pigpio library and run pigpio daemon before starting your script.
sudo apt-get update
sudo apt-get install pigpio python-pigpio python3-pigpio
python3 -mpip install pigpio_encoder
(consider add --user option)sudo pigpiod
import the module
from pigpio_encoder.rotary import Rotary
create a callback function for the Rotary Encoder counter.
You must pass a positional argument to retrieve the counter value.
def rotary_callback(counter):
# some action with counter...
create a callback function for Up-Rotation events.
def up_callback():
# some action if rotated upward
create a callback function for Down-Rotation events.
def down_callback():
# some action if rotated downward
create callbacks functions for the Switch
If you intend to use the switch you must create at least the "short press" callback. The "long press" callback is necessary if you want to use that feature.
def sw_short_callback():
# some action...
def sw_long_callback():
# some action...
```
create the rotary object
here you setup the gpio id as keyword argument. If you don't pass the switch parameter the switch won't be activated.
my_rotary = Rotary(
clk_gpio=<gpio_id of clk signal>,
dt_gpio=<gpio_id of dt signal>,
sw_gpio=<gpio_id of switch signal>
)
setup the rotary encoder for counting
here you can setup min and max values for the encoder, the increase/decrease value, a debounce value (default 300ms) and the callback function.
my_rotary.setup_rotary(
min=<min_value>,
max=<max_value>,
scale=<scale_value>,
debounce=<debounce_value>,
rotary_callback=<rotary_callback>
)
Optional setup for up and down rotation events
here you can setup min and max values for the encoder, the increase/decrease value, a debounce value (default 300ms) and the callback functions.
my_rotary.setup_rotary(
min=<min_value>,
max=<max_value>,
scale=<scale_value>,
debounce=<debounce_value>,
up_callback=<up_callback>
down_callback=<down_callback>
)
setup the switch
if you have specified the switch pin when creating the encoder object, here you can setup the debounce value, the long press option and the callbacks.
my_rotary.setup_switch(
debounce=<debounce_value>,
long_press=<True>,
sw_short_callback=<sw_short_callback>,
sw_long_callback=<sw_long_callback>
)
start the listener
my_rotary.watch()
Please note that calling .watch() this is only for demostration purposes. It is not neccessary for the encoder to operate it can even cause problems.
from pigpio_encoder.rotary import Rotary
def rotary_callback(counter):
print("Counter value: ", counter)
def sw_short():
print("Switch pressed")
def up_callback():
print("Up rotation")
def down_callback():
print("Down rotation")
my_rotary = Rotary(clk_gpio=27, dt_gpio=22, sw_gpio=17)
my_rotary.setup_rotary(
rotary_callback=rotary_callback,
up_callback=up_callback,
down_callback=down_callback,
)
my_rotary.setup_switch(sw_short_callback=sw_short)
my_rotary.watch()
Please note that calling .watch() this is only for demostration purposes. It is not neccessary for the encoder to operate it can even cause problems.
from pigpio_encoder.rotary import Rotary
def rotary_callback(counter):
print("Counter value: ", counter)
def sw_short():
print("Switch short press")
def sw_long():
print("Switch long press")
my_rotary = Rotary(
clk_gpio=27,
dt_gpio=22,
sw_gpio=17
)
my_rotary.setup_rotary(
min=10,
max=300,
scale=5,
debounce=200,
rotary_callback=rotary_callback
)
my_rotary.setup_switch(
debounce=200,
long_press=True,
sw_short_callback=sw_short,
sw_long_callback=sw_long
)
my_rotary.watch()
Please note that calling .watch() this is only for demostration purposes. It is not neccessary for the encoder to operate it can even cause problems.