GPIO API Reference

The GPIO (General Purpose Input/Output) API provides access to 32 programmable I/O pins that can be configured for digital or analog operations. Each pin supports voltages from -25V to +25V for inputs and 0 to 24V for outputs.

Accessing GPIO

NodeJS
Python

const gpio = tester.gpio;

gpio = tester.gpio

GPIO Module Methods

`reset()`

Resets all GPIO pins to their default configuration.

NodeJS
Python

await tester.gpio.reset();

tester.gpio.reset()

Returns: Promise<void> / None

`digital(io)`

Access a specific GPIO pin for digital operations.

NodeJS
Python

const pin = tester.gpio.digital(0);

pin = tester.gpio.digital(0)

Parameters:

io (number / int): GPIO pin number (0-31)

Returns: DigitalIO instance

`analog(io)`

Access a specific GPIO pin for analog operations.

NodeJS
Python

const pin = tester.gpio.analog(0);

pin = tester.gpio.analog(0)

Parameters:

io (number / int): GPIO pin number (0-31)

Returns: AnalogIO instance

`hold()`

Holds (freezes) the current state of all GPIO pins. This allows buffering multiple write commands before applying them simultaneously.

NodeJS
Python

await tester.gpio.hold();

tester.gpio.hold()

Returns: Promise<SyncConfiguration> / SyncConfiguration - Configuration with action: "hold"

note

Prevents external changes to GPIO states until release() is called. Digital and analog writes issued between hold() and release() are buffered on the device and applied together on release.

`release()`

Releases the outputs, applying all buffered writes simultaneously. Releasing also switches the device to sync-slave mode: its outputs then follow the SYNC-IN line, so an external master's hold freezes them (see Output synchronization).

NodeJS
Python

await tester.gpio.release();

tester.gpio.release()

Returns: Promise<SyncConfiguration> / SyncConfiguration - Configuration with action: "release"

`read_config(io)`

Reads back the current configuration of a specific I/O pin.

NodeJS
Python

const config = await tester.gpio.read_config(0);

config = tester.gpio.read_config(0)

Parameters:

io (number / int): GPIO pin number (0-31)

Returns: Promise<GpioConfiguration> / GpioConfiguration - The pin's current configuration

`read_sync()`

Reads the current synchronization hold state. Returns { hold_state: "held" } while outputs are frozen and { hold_state: "released" } otherwise.

NodeJS
Python

const state = await tester.gpio.read_sync();

state = tester.gpio.read_sync()

Returns: Promise<SyncState> / SyncState - The current synchronization hold state

Type: SyncState = { hold_state: "held" | "released" }

DigitalIO Class

Input thresholds may be equal or in either order. If both input-state comparisons match, the low-threshold comparison takes precedence and reads false. A partial REST PATCH retains omitted thresholds. The typed SDK configure_input method requires both vil and vih.

`configure_input(config)`

Configures the pin as a digital input with custom thresholds.

NodeJS
Python

await pin.configure_input({
  vil: 0.8,  // Input low threshold
  vih: 2.0   // Input high threshold
});

pin.configure_input(vil=0.8, vih=2.0)

Parameters:

config (PartialDigitalInputConfiguration):
- vil (number / float, required): Voltage input low threshold ([-25, 25] V, inclusive)
- vih (number / float, required): Voltage input high threshold ([-25, 25] V, inclusive)

Returns: Promise<DigitalInputConfiguration> / DigitalInputConfiguration - Full configuration including mode and direction

Exceptions:

Throws validation error if vil or vih is outside the inclusive range [-25, 25] V

`configure_output(config)`

Configures the pin as a digital output with custom voltage levels and thresholds.

NodeJS
Python

await pin.configure_output({
  value: true,      // Initial state
  vol: 0.0,         // Output low voltage
  voh: 3.3,         // Output high voltage
  vil: 0.8,         // Optional input low threshold
  vih: 2.0          // Optional input high threshold
});

pin.configure_output(
    value=True,   # Initial state
    vol=0.0,      # Output low voltage
    voh=3.3,      # Output high voltage
    vil=0.8,      # Optional input low threshold
    vih=2.0       # Optional input high threshold
)

Parameters:

config (PartialDigitalOutputConfiguration):
- value (boolean | number / bool | int, required): Initial output state (true/1 = high, false/0 = low)
- vol (number / float, required): Voltage output low level (0 to 24V)
- voh (number / float, required): Voltage output high level (0 to 24V)
- vil (number / float, optional): Voltage input low threshold ([-25, 25] V, inclusive)
- vih (number / float, optional): Voltage input high threshold ([-25, 25] V, inclusive)

Returns: Promise<DigitalOutputConfiguration> / DigitalOutputConfiguration - Full configuration

Exceptions:

Throws validation error if vol or voh is outside the range [0, 24]
Throws validation error if vil or vih is outside the inclusive range [-25, 25] V

note

When vil and vih are omitted, they are automatically deduced from the given voh and vol parameters.

`configure_open_drain(config)`

Configures the pin as an open-drain output (useful for I2C, 1-Wire, etc.).

NodeJS
Python

await pin.configure_open_drain({
  value: true,
  vil: 0.8,
  vih: 2.0
});

pin.configure_open_drain(
    value=True,
    vil=0.8,
    vih=2.0
)

Parameters:

config (PartialOpenDrainConfiguration):
- value (boolean | number / bool | int, required): Initial state (true = floating/high-Z, false = low)
- vil (number / float, required): Voltage input low threshold ([-25, 25] V, inclusive)
- vih (number / float, required): Voltage input high threshold ([-25, 25] V, inclusive)

Returns: Promise<OpenDrainConfiguration> / OpenDrainConfiguration - Full configuration

Exceptions:

Throws validation error if vil or vih is outside the inclusive range [-25, 25] V

`read()`

Reads the current logical state of the pin.

NodeJS
Python

const state = await pin.read();
console.log("Pin is", state ? "HIGH" : "LOW");

state = pin.read()
print("Pin is", "HIGH" if state else "LOW")

Returns: Promise<boolean> / bool - true for HIGH, false for LOW

`write(value)`

Writes a logical value to the pin (must be configured as output).

NodeJS
Python

await pin.write(true);   // Set HIGH
await pin.write(false);  // Set LOW
await pin.write(1);      // Set HIGH (numeric)
await pin.write(0);      // Set LOW (numeric)

pin.write(True)   # Set HIGH
pin.write(False)  # Set LOW
pin.write(1)      # Set HIGH (numeric)
pin.write(0)      # Set LOW (numeric)

Parameters:

value (boolean | number / bool | int): Value to write (true/1 = HIGH, false/0 = LOW)

Returns: Promise<boolean> / bool - The written value as boolean

AnalogIO Class

`configure_input()`

Configures the pin as an analog input for voltage measurement.

NodeJS
Python

await pin.configure_input();

pin.configure_input()

Returns: Promise<AnalogInputConfiguration> / AnalogInputConfiguration - Configuration with mode "analog" and direction "input"

`configure_output(value)`

Configures the pin as an analog output and sets the initial voltage.

NodeJS
Python

await pin.configure_output(3.3);  // Set to 3.3V

pin.configure_output(3.3)  # Set to 3.3V

Parameters:

value (number / float): Initial output voltage (0 to 24V)

Returns: Promise<AnalogOutputConfiguration> / AnalogOutputConfiguration - Full configuration

Exceptions:

Throws validation error if value is outside the range [0, 24]

`read()`

Reads the current analog voltage at the pin.

NodeJS
Python

const voltage = await pin.read();
console.log("Voltage:", voltage, "V");

voltage = pin.read()
print(f"Voltage: {voltage} V")

Returns: Promise<number> / float - Measured voltage in volts

`write(value)`

Sets the analog output voltage (must be configured as analog output).

NodeJS
Python

await pin.write(3.3);   // Set to 3.3V
await pin.write(5.0);   // Set to 5.0V
await pin.write(12.5);  // Set to 12.5V

pin.write(3.3)   # Set to 3.3V
pin.write(5.0)   # Set to 5.0V
pin.write(12.5)  # Set to 12.5V

Parameters:

value (number / float): Voltage to output (0 to 24V)

Returns: Promise<number> / float - The set voltage

Exceptions:

Throws validation error if value is outside the range [0, 24]

Types

`DigitalInputConfiguration`

{
  mode: "digital",
  direction: "input",
  vil: number,  // [-25, 25] V, inclusive
  vih: number   // [-25, 25] V, inclusive
}

`DigitalOutputConfiguration`

{
  mode: "digital",
  direction: "output",
  value: boolean,
  vol: number,   // 0 to 24V
  voh: number,   // 0 to 24V
  vil: number,   // [-25, 25] V, inclusive
  vih: number    // [-25, 25] V, inclusive
}

`OpenDrainConfiguration`

{
  mode: "digital",
  direction: "open_drain",
  value: boolean,
  vil: number,  // [-25, 25] V, inclusive
  vih: number   // [-25, 25] V, inclusive
}

`AnalogInputConfiguration`

{
  mode: "analog",
  direction: "input"
}

`AnalogOutputConfiguration`

{
  mode: "analog",
  direction: "output",
  value?: number  // 0 to 24V
}

`SyncState`

{ hold_state: "held" | "released" }

Notes

All 32 pins support both digital and analog modes
Voltage range: -25 V to +25 V for measured inputs and digital thresholds, 0 to 24 V for outputs. Both ranges are inclusive.
Open-drain mode is ideal for protocols requiring external pull-ups (I2C, 1-Wire)
When writing digital values, both boolean and number (0/1) are accepted
Analog readings provide precise voltage measurements
Use hold() and release() for synchronized multi-pin operations

Accessing GPIO​

GPIO Module Methods​

reset()​

digital(io)​

analog(io)​

hold()​

release()​

read_config(io)​

read_sync()​

DigitalIO Class​

configure_input(config)​

configure_output(config)​

configure_open_drain(config)​

read()​

write(value)​

AnalogIO Class​

configure_input()​

configure_output(value)​

read()​

write(value)​

Types​

DigitalInputConfiguration​

DigitalOutputConfiguration​

OpenDrainConfiguration​

AnalogInputConfiguration​

AnalogOutputConfiguration​

SyncState​

Notes​

Accessing GPIO

GPIO Module Methods

`reset()`

`digital(io)`

`analog(io)`

`hold()`

`release()`

`read_config(io)`

`read_sync()`

DigitalIO Class

`configure_input(config)`

`configure_output(config)`

`configure_open_drain(config)`

`read()`

`write(value)`

AnalogIO Class

`configure_input()`

`configure_output(value)`

`read()`

`write(value)`

Types

`DigitalInputConfiguration`

`DigitalOutputConfiguration`

`OpenDrainConfiguration`

`AnalogInputConfiguration`

`AnalogOutputConfiguration`

`SyncState`

Notes