Rotary Encoder Module v2 analog output

rk96

Hello,

For the REM v2 description, it says "two analog output channels configurable to report the wheel position or to deliver 3.3V sync pulses."
How do I configure these channels?

Thank you.

trose_neuro

rk96 wrote
Hello,

For the REM v2 description, it says "two analog output channels configurable to report the wheel position or to deliver 3.3V sync pulses."
How do I configure these channels?

Thank you.

Same question here.

I assume by adding that to the module 2 Arduino code - I think this is not implemented yet. At least I cannot find anything related to that here: https://github.com/sanworks/Bpod_RotaryEncoder_Firmware/blob/master/RotaryEncoderModule/RotaryEncoderModule.ino

Josh: do you have a reference implementation? Otherwise, we'd simply fork and add.

actually: turns out it is implemented already in our current version. We simply did not use the new hardware until now. First output is position, second is sync.

best
Tobias

rk96

For more context, the REMv2 is replacing the REMv1 in our IBL rig so we can track the wheel position. I am facing two issues at the moment:
First, the first analog output works great when we do not have thresholds set. The voltage correlates well with the wheel position and traverses through the whole 5V range smoothly.
However, when I have the wheel thresholds set at [-15,15] degrees, the deflections in the analog signal before threshold crossing (and reset to 0) are very small (10s of mV) with respect to the whole 5V range. I am wondering if there is a way to scale the voltage?
Second, the second analog output does not seem to give me any sync pulses. I am just reading noise from 0 to 5V.
Thank you.

Josh

Hello RK,

The analog output channel reports the wheel position.
If your state machine code resets the position (command 'Z' in a state's output actions), the analog signal will also reset to reflect the new position.
Is this what's happening? If not, please share the section of your code with addState()

The second analog channel currently toggles its logic each time the position is checked (at 10kHz). I'm open to suggestions regarding additional sync schemes to add. The line could be toggled only if the position changes, every 100ms, etc.

Thanks,
Josh

rk96

import logging
import matplotlib.pyplot as plt
from pybpodapi.protocol import Bpod, StateMachine
from iblrig.bpod_helper import BpodMessageCreator
from iblrig.rotary_encoder import MyRotaryEncoder

log = logging.getLogger("iblrig")
# =============================================================================
# CONNECT TO BPOD
# =============================================================================
bpod = Bpod()

# Bpod message creator
msg = BpodMessageCreator(bpod)

re_reset = msg.rotary_encoder_reset()
th_reset = msg.reset_thresholds()
bpod = msg.return_bpod()

WHEEL_THRESHOLD = [-30, 30]
STIM_GAIN = 1
COM_ROTARY_ENCODER = "COM6"
ROTARY_ENCODER = MyRotaryEncoder(WHEEL_THRESHOLD, STIM_GAIN, COM_ROTARY_ENCODER)
threshold_events_dict = ROTARY_ENCODER.THRESHOLD_EVENTS  # dictionary with key being angle and value being RE event name
move_left = threshold_events_dict[WHEEL_THRESHOLD[0]]
move_right = threshold_events_dict[WHEEL_THRESHOLD[1]]
RESPONSE_PERIOD = 5
ITI = 0
REWARD_VALVE_TIME = 0.1

for i in range(99999):  # Main loop

    log.info(f"Starting trial: {i + 1}")

    sma = StateMachine(bpod)
    sma.set_global_timer_legacy(timer_id=1, timer_duration=RESPONSE_PERIOD)
    sma.set_global_timer_legacy(timer_id=2, timer_duration=ITI)

    sma.add_state(
        state_name="trial_start",
        state_timer=0,  
        state_change_conditions={"Tup": "reset_rotary_encoder"},
        output_actions=[(Bpod.OutputChannels.GlobalTimerTrig,1)],
    )  

    sma.add_state(
        state_name="reset_rotary_encoder",
        state_timer=0,
        state_change_conditions={"Tup": "response_period",
            "GlobalTimer1_End": "ITI"
        },
        output_actions=[("Serial1", re_reset)],
    )

    sma.add_state(  
        state_name="response_period",
        state_timer=0,
        state_change_conditions={
            move_left: "reward",
            move_right: "reward",
            "GlobalTimer1_End": "ITI"
        },
        output_actions=[],
    ) 

    sma.add_state(
        state_name="reward",
        state_timer = REWARD_VALVE_TIME,
        state_change_conditions={
            "Tup": "ITI",
            "GlobalTimer1_End": "ITI"
        },
        output_actions=[("Valve1", 255),("Serial1", re_reset)],
    )

    sma.add_state(
        state_name="ITI",
        state_timer = ITI,
        state_change_conditions={
            "Tup": "exit_state",
        },
        output_actions=[("Serial1", re_reset)],
    )

    sma.add_state(
        state_name="exit_state",
        state_timer=0,
        state_change_conditions={"Tup": "exit"},
        output_actions=[("Serial1", re_reset)],
    )

    # Send state machine description to Bpod device
    bpod.send_state_machine(sma)
    # Run state machine
    if not bpod.run_state_machine(sma):  # Locks until state machine 'exit' is reached
        break

Josh wrote[quote='Josh' pid='4583' dateline='1677039496']
Hello RK,

The analog output channel reports the wheel position.
If your state machine code resets the position (command 'Z' in a state's output actions), the analog signal will also reset to reflect the new position.
Is this what's happening? If not, please share the section of your code with addState()

The second analog channel currently toggles its logic each time the position is checked (at 10kHz). I'm open to suggestions regarding additional sync schemes to add. The line could be toggled only if the position changes, every 100ms, etc.

Thanks,
Josh

I have videos showing what I am seeing. However, I can't figure out how to post them on the forum.

Josh

Hi RK,

15 degrees should correspond to _200mV.

If you put a breakpoint after this line and before the state machine setup:

ROTARY_ENCODER = MyRotaryEncoder(WHEEL_THRESHOLD, STIM_GAIN, COM_ROTARY_ENCODER)

Does the analog signal have a compressed range?