gpiod driver

jumpstarter-driver-gpiod provides functionality for interacting with gpiod GPIO pins for digital input/output operations.

This requires the /dev/gpiochip[0..N] device available on the system, and you can use the gpioinfo gpiod tool to list the available GPIO lines.

Installation

:substitutions:
$ pip3 install --extra-index-url {{index_url}} jumpstarter-driver-gpiod

Configuration

The gpiod driver provides three main driver types:

DigitalOutput Configuration

Example configuration for digital output:

export:
  led_output:
    type: jumpstarter_driver_gpiod.driver.DigitalOutput
    config:
      device: "/dev/gpiochip0"
      line: 18
      drive: "push_pull"
      active_low: false
      bias: "pull_up"
      initial_value: "inactive"

DigitalInput Configuration

Example configuration for digital input:

export:
  button_input:
    type: jumpstarter_driver_gpiod.driver.DigitalInput
    config:
      line: 17
      active_low: false
      bias: "pull_up"

PowerSwitch Configuration

Example configuration for power switching:

export:
  power_switch:
    type: jumpstarter_driver_gpiod.driver.PowerSwitch
    config:
      line: 18
      mode: "push_pull"
      active_low: false
      bias: "pull_up"
      initial_value: "inactive"

Config parameters

API Reference

DigitalOutputClient

.. autoclass:: jumpstarter_driver_gpiod.client.DigitalOutputClient()
    :members: on, off, read

DigitalInputClient

.. autoclass:: jumpstarter_driver_gpiod.client.DigitalInputClient()
    :members: wait_for_active, wait_for_inactive, wait_for_edge, read

Examples

Digital Output Examples

Basic LED control:

# Turn LED on
led_output.on()

# Turn LED off
led_output.off()

# Read current state
state = led_output.read()
print(f"LED state: {state}")

Digital Input Examples

Button input with edge detection:

# Read current input state
state = button_input.read()
print(f"Button state: {state}")

# Wait for button press (active state)
button_input.wait_for_active(timeout=10.0)

# Wait for button release (inactive state)
button_input.wait_for_inactive(timeout=10.0)

# Wait for rising edge (button press)
button_input.wait_for_edge("rising", timeout=10.0)

# Wait for falling edge (button release)
button_input.wait_for_edge("falling", timeout=10.0)

Power Switch Examples

Power control for devices:

# Turn power on
power_switch.on()

# Turn power off
power_switch.off()

# Read current power state
state = power_switch.read()
print(f"Power state: {state}")

Pin Configuration Details

Drive Modes

• push_pull: Standard push-pull output (default)
• open_drain: Open-drain output (useful for I2C, etc.)
• open_source: Open-source output

Bias Configuration

• as_is: No bias (default)
• pull_up: Internal pull-up resistor
• pull_down: Internal pull-down resistor
• disabled: Disable bias

Active Low vs Active High

• active_low: false (default): Pin is active when HIGH
• active_low: true: Pin is active when LOW

Initial Values

For output pins, you can set the initial state:

• "inactive" or "off" or False: Start with pin LOW
• "active" or "on" or True: Start with pin HIGH

Hardware Requirements

• gpiod with GPIO access
• Python gpiod library installed
• Appropriate permissions to access /dev/gpiochip0

Error Handling

The driver includes comprehensive error handling for:

• Invalid pin numbers
• Invalid drive/bias configurations
• Hardware access errors
• Timeout conditions for input operations