Position based trigger from rotary encoder

[bdudok]

Currently the task script needs to poll the position variable using a timer, whenever we want to do something that depends on distance traveled or reaching a specific treadmill location. Instead, it would be so much better to get an interrupt at a pre-set position value.

I looked at the running wheel example task.

The task sets up a trigger based on velocity:

bonus_trigger = Analog_trigger(
    threshold=v.bonus_velocity_threshold,
    rising_event="bonus_earned",
)

Would it be possible to set something similar up based on position, ie. it generates an interrupt when that position is reached? I would need to be able to edit the threshold during runtime. This is how I do this currently, which is not ideal:

belt_pos = Rotary_encoder(name='pos', output='position',)

# Then in a state function:

    elif event == 'poll_timer':
        if belt_pos.position > v.next_reward:
            goto_state('reward_zone_entry')
        else:
            set_timer('poll_timer', v.poll_resolution, output_event=True)

I don't think Analog trigger would work for this, because that requires an analog input on a pin, as far as I undeerstand, and position is computed on the board, not by the periphery.

[alustig3]

Does something like this work for you?

from pyControl.utility import *
from devices import *
from pyControl.hardware import Analog_trigger

# Variables.

v.reward_duration = 100 * ms  # Time reward solenoid is open for.
v.target_positions = [100, 200, 300, 400, 500]

target_reached_trigger = Analog_trigger(
    threshold=v.target_positions[0],
    rising_event="reached_target",
    falling_event="reached_target",
)

# Instantiate hardware - would normally be in a seperate hardware definition file.

board = Breakout_1_2()  # Breakout board.

running_wheel = Rotary_encoder(
    name="running_wheel",
    sampling_rate=100,
    output="position",
    triggers=[target_reached_trigger],
)  # Running wheel must be plugged into port 1 of breakout board.

solenoid = Digital_output(board.port_2.POW_A)  # Reward delivery solenoid.


# States and events.

states = [
    "running_for_reward",
    "reward",
]

events = [
    "reached_target",
]

initial_state = "running_for_reward"


# State behaviour functions.


def running_for_reward(event):
    if event == "reached_target":
        goto_state("reward")


def reward(event):
    if event == "entry":
        timed_goto_state("running_for_reward", v.reward_duration)
        solenoid.on()
    elif event == "exit":
        solenoid.off()
        new_target_position = choice(v.target_positions)
        print(f"New target position: {new_target_position}")
        target_reached_trigger.set_threshold(new_target_position)

[bdudok]

Hi Andy, Thank you, this looks exactly like what I need, I appreciate your help. Unfortunately, Analog_trigger is not available in the version we use, but I will give it a try after the next update. Thanks, Barna From: Andy Lustig ***@***.***> Date: Thursday, March 26, 2026 at 3:42 PM To: pyControl/code ***@***.***> Cc: bdudok ***@***.***>, Author ***@***.***> Subject: Re: [pyControl/code] Position based trigger from rotary encoder (Discussion #172) Does something like this work for you? from pyControl.utility import * from devices import * from pyControl.hardware import Analog_trigger # Variables. v.reward_duration = 100 * ms # Time reward solenoid is open for. v.target_positions = [100, 200, 300, 400, 500] target_reached_trigger = Analog_trigger( threshold=v.target_positions[0], rising_event="reached_target", falling_event="reached_target", ) # Instantiate hardware - would normally be in a seperate hardware definition file. board = Breakout_1_2() # Breakout board. running_wheel = Rotary_encoder( name="running_wheel", sampling_rate=100, output="position", triggers=[target_reached_trigger], ) # Running wheel must be plugged into port 1 of breakout board. solenoid = Digital_output(board.port_2.POW_A) # Reward delivery solenoid. # States and events. states = [ "running_for_reward", "reward", ] events = [ "reached_target", ] initial_state = "running_for_reward" # State behaviour functions. def running_for_reward(event): if event == "reached_target": goto_state("reward") def reward(event): if event == "entry": timed_goto_state("running_for_reward", v.reward_duration) solenoid.on() elif event == "exit": solenoid.off() new_target_position = choice(v.target_positions) print(f"New target position: {new_target_position}") target_reached_trigger.set_threshold(new_target_position) — Reply to this email directly, view it on GitHub<#172?email_source=notifications&email_token=AGZ7XEUEMPGLB6SEPOTVE2L4SWI3PA5CNFSNUABIM5UWIORPF5TWS5BNNB2WEL2ENFZWG5LTONUW63SDN5WW2ZLOOQXTCNRTGMZDONZTUZZGKYLTN5XKMYLVORUG64VFMV3GK3TUVRTG633UMVZF6Y3MNFRWW#discussioncomment-16332773>, or unsubscribe<https://github.com/notifications/unsubscribe-auth/AGZ7XEXP6YCT7YAE4PKL4FD4SWI3PAVCNFSM6AAAAACXA67OQ6VHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTMMZTGI3TOMY>. You are receiving this because you authored the thread.