PinProbe Item¶

class PinProbe¶: Represents a digital IO pin on the launchpad probe board.

Inherits:	`Component`
Enumerations:	`PullMode`, `Type`, `Value`
Properties:	`ioid`, `port`, `pullMode`, `type`, `value`

Detailed Description¶

A PinProbe component represents an IO pin on the launchpad probe board. It can be used to physically interface Qst to a Device Under Test (DUT) and stimulate/analyse digital hardware signals.

Each PinProbe item can be configured either as input or output. Additional pull-up or pull-down resistors may be activated for inputs. The output state is set by writing to the output property and events on the probe wire can be observed by attaching a signal handler to the valueChanged() signal.

Example:

import qst 1.0

// Assuming a DUT with an LED and a button and two wires of a
// launchpad probe board attached.
// On a falling edge of the button IO, the LED shall be turned on.
Testcase {
    name: "test-app"

    property string port: "ttyACM3"

    PinProbe {
        id: button
        port: test.port
        type: PinProbe.Write
        value: PinProbe.High
    }

    PinProbe {
        id: led
        port: test.port
        type: PinProbe.Read

        onValueChanged: {
            Qst.info("The LED value is now " + led.value);
        }
    }

    function run() {
        Qst.wait(50);
        Qst.compare(led.value, PinProbe.Low, "LED should be off but is on");
        // Stimulate button press
        button.value = PinProbe.Low;
        Qst.wait(5);
        Qst.compare(led.value, PinProbe.High, "LED should be on but is off");
    }
}

PinProbe currently only emits the valueChanged() signal. All other properties are assumed to be constant during application life time.

Enumerations¶

enum Type¶

Configures the pin direction.

enumerator Read¶: Configures the pin as input.

enumerator Write¶: Configures the pin as output.

enum PullMode¶

Whether internal pull resistors should be enabled or not.

enumerator PullDisabled¶: Pull resistors are disabled.

enumerator PullDown¶: Enables a pull-down resistor on the pin.

enumerator PullUp¶: Enables a pull-up resistor on the pin.

enum Value¶

The logic level on the hardware pin.

enumerator Low¶: Equals to 0 and false.

enumerator High¶: Equals to 1 and true.

enumerator Undefined¶: No value has been assigned to this pin yet.

Properties¶

int ioid¶

Default:	0

Specifies the IO identifier on the probe board. The range is usually 0..31, but not all IOs might be available.

string port¶

Default:	empty

The serial port identifier of the probe board. On Windows, this is usually COMx while on Linux systems ttyACMx or ttyUSBx is commonly used.