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Control digital input/output pins for digital signaling and control.

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Import

from lager import Net, NetType

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Methods

MethodDescription
input()Read digital pin state
output(level)Set digital pin state
wait_for_level(level, ...)Wait for pin to reach a target level

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Method Reference

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Net.get(name, type=NetType.GPIO)

Get a GPIO net by name. 
from lager import Net, NetType

pin = Net.get('LED', type=NetType.GPIO)
Parameters:
ParameterTypeDescription
namestrName of the GPIO net
typeNetTypeMust be NetType.GPIO
Returns: GPIO Net instance

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input()

Read the digital state of the pin. 
from lager import Net, NetType

pin = Net.get('BUTTON', type=NetType.GPIO)
state = pin.input()

if state:
    print("Pin is HIGH")
else:
    print("Pin is LOW")
Returns: int - 0 for LOW, 1 for HIGH

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output(level)

Set the digital state of the pin. 
from lager import Net, NetType

pin = Net.get('LED', type=NetType.GPIO)

# Set HIGH
pin.output(1)

# Set LOW
pin.output(0)
ParameterTypeDescription
levelint or str0/1, “low”/“high”, “off”/“on”, “true”/“false”

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wait_for_level(level, timeout=None, ...)

Wait for the pin to reach a target level. Blocks until the pin reads the specified level or the timeout expires. The LabJack T7 uses hardware streaming at up to 20 kHz for fast edge detection. Other hardware uses software polling. 
from lager import Net, NetType

pin = Net.get('INTERRUPT', type=NetType.GPIO)

# Wait for pin to go HIGH (block forever)
elapsed = pin.wait_for_level(1)
print(f"Pin went HIGH after {elapsed:.3f}s")

# Wait with timeout
try:
    elapsed = pin.wait_for_level(0, timeout=5.0)
    print(f"Pin went LOW after {elapsed:.3f}s")
except TimeoutError:
    print("Timed out waiting for pin")
Parameters:
ParameterTypeDefaultDescription
levelint or strrequiredTarget level: 0/1, “low”/“high”, “off”/“on”
timeoutfloat or NoneNoneMaximum seconds to wait. None = wait forever.
scan_rateint20000Sample rate in Hz (LabJack T7 only)
scans_per_readint2Batch size per read (LabJack T7 only; lower = faster reaction)
poll_intervalfloat0.01Seconds between polls (non-LabJack hardware only)
Returns: float - Elapsed time in seconds until the level was detected Raises: TimeoutError if the timeout expires before the target level is reached Hardware-specific behavior:
HardwareMethodDefault Rate
LabJack T7Hardware streaming (ljm.eStreamStart)20,000 Hz
USB-202Software polling100 Hz (10 ms interval)

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Examples

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Read Button State

from lager import Net, NetType

button = Net.get('BUTTON', type=NetType.GPIO)

state = button.input()
if state:
    print("Button pressed")
else:
    print("Button released")

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Control LED

from lager import Net, NetType

led = Net.get('LED', type=NetType.GPIO)

# Turn on
led.output(1)

# Turn off
led.output(0)

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Wait for Interrupt

from lager import Net, NetType

irq_pin = Net.get('INTERRUPT', type=NetType.GPIO)

# Wait for interrupt (rising edge)
try:
    elapsed = irq_pin.wait_for_level(1, timeout=10.0)
    print(f"Interrupt detected after {elapsed:.3f}s")
except TimeoutError:
    print("No interrupt within 10 seconds")

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Button-Controlled LED

from lager import Net, NetType
import time

button = Net.get('BUTTON', type=NetType.GPIO)
led = Net.get('LED', type=NetType.GPIO)

print("Press Ctrl+C to exit")

while True:
    try:
        if button.input():
            led.output(1)
        else:
            led.output(0)
        time.sleep(0.1)
    except KeyboardInterrupt:
        led.output(0)
        break

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Toggle Output

from lager import Net, NetType
import time

output_pin = Net.get('SIGNAL', type=NetType.GPIO)

# Generate 10 pulses
for i in range(10):
    output_pin.output(1)
    time.sleep(0.5)
    output_pin.output(0)
    time.sleep(0.5)

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Supported Hardware

HardwarePinsLogic Level
LabJack T7FIO0-FIO7, EIO0-EIO7, CIO0-CIO33.3V
MCC USB-202DIO0-DIO75V TTL

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Pin Naming

LabJack T7:
Pin InputChannel
0-7FIO0-FIO7
8-15EIO0-EIO7
16-19CIO0-CIO3
"FIO0"-"FIO7"FIO0-FIO7
MCC USB-202:
Pin InputChannel
0-7DIO0-DIO7
"DIO0"-"DIO7"DIO0-DIO7

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Notes

  • GPIO nets work directly without enable()/disable() calls
  • input() returns 0 or 1
  • output() accepts integers (0/1) or strings (“high”/“low”, “on”/“off”, “true”/“false”)
  • wait_for_level() blocks the calling thread until the target level is detected
  • LabJack T7 wait_for_level() uses hardware streaming for sub-millisecond detection
  • Net names must match those configured on the Lager Box