Yes, you can use a 4-pin ultrasonic sensor like the HC-SR04 with the EZ-B IoTiny. The HC-SR04 typically has four pins: VCC, Trig (Trigger), Echo, and GND (Ground). Here's how you would wire it up to the IoTiny:

1. VCC (Power): Connect this to one of the power pins on the IoTiny that provides the appropriate voltage for your sensor (typically 5V).

2. Trig (Trigger): Connect this to one of the digital output ports on the IoTiny. This port will be used to send the pulse to initiate the sensor's ultrasonic signal.

3. Echo: Connect this to a different digital input port on the IoTiny. This port will be used to read the signal returned to the sensor.

4. GND (Ground): Connect this to one of the ground pins on the IoTiny.

In the ARC software, you will need to configure the Ultrasonic Distance skill with the appropriate trigger and echo ports that you have connected to the HC-SR04 sensor. Set the trigger port to the digital output you've connected to the Trig pin of the sensor, and the echo port to the digital input connected to the Echo pin.

Remember that the IoTiny operates at 3.3V logic levels, but it is typically 5V tolerant on the digital input pins, which means it should work with the HC-SR04 sensor. However, always check the specifications of your particular sensor and the IoTiny to ensure compatibility and to avoid damaging your components.