# External trigger

The Satellite includes the possibility to playback tracks through a sensor or software connection. For this, the universal port labeled 'I/O' can configurated in two ways:

Sensor Input: The port includes two GPIO-Pins (General purpose input output) that can be triggered through a sensor input such as the button-sensor board inlcuded in the DevKit.
Software protocoll: For advanced prototypes, you can trigger feedback through a software protocoll such as UART.

You can select from Off, Loop, Trigger, and UART mode.

Off: The port is completely disabled.
Loop: When a signal is present, the track is playing in loop until the signal is gone.
Trigger ⭐ Starter: When a signal is present, the track is played once.
UART ⭐ Pro: In UART mode, you can attach another microcontroller to the GPIOs to communicate through UART to trigger saved tracks.

# Loop mode

In loop mode, the track saved to “Pin 1” will be played back repeatedly as long as the physical 'GPIO Pin 1' is pulled to a logical HIGH value (3.3V) or the touch sensor on top of the Satellite is touched. The ⭐ Starter tier enables 'GPIO PIN 2'.

In the free version, only GPIO 1 is available as sensor input

# Trigger mode ⭐ Starter

In trigger mode, the track saved to 'Pin 1' or 'Pin 2' will be played back once when the physical 'GPIO Pin 1/ 2' is pulled to a logical HIGH value (3.3V) or the touch sensor on top of the Satellite is touched.

Rising Edge: The assigned track is played once when the signal value changes from off/ low to on/ high. This represents a touch event.
Falling Edge: The assigned track is played once when the signal value changes from on/ high to off/ low. This represents a release event.

To simulate a mechanical button, you can assign a track to be triggerd by a rising edge and a falling edge event. Using a touch sensot, the user will feel haptic feedback when touching and lifting the finger.

# Assigning tracks to Pins

Two buttons, labeled “Pin 1”, and “Pin 2” serve as a way to upload a track onto the Satellite. If the satellite is in Trigger mode, the track will be saved to the Rising event (see The external trigger menu) by default.

Pin 1: Corresponds to the physical GPIO Pin 1 on the I/O port of the satellite.
Pin 2: Corrensponds to the physical GPIO Pin 2 on the I/O port of the satellite.

Only one track can be saved on each Pin. Saving a track will overwrite what was previously saved. By pressing the 'x' symbol, you can remove saved tracks.

# UART mode ⭐ Pro

In UART mode, you can attach another microcontroller to the GPIOs to communicate through UART to trigger saved tracks. Learn more:

UART interface

../../api/externaltrigger/

# The upload tracks button ⭐ Pro

Upload tracks allow you to save all tracks of the current project to the satellite to later trigger it through the serial or UART interface. Learn more:

External Software Trigger