GPIO stands for General Purpose Input/Output. It’s a standard interface used to connect microcontrollers to other electronic devices. For example, it can be used with sensors, diodes, displays, and System-on-Chip modules. Estimote Location Beacons (Hardware Revision F2.3 and later) are equipped with GPIO. It allows for providing external power supply, remote control of connected devices, broadcasting more contextual data, or defining contents for custom Bluetooth data packets.
Support for GPIO is available in the latest verions of Estimote app and SDK.
GPIO can be used in three modes:
- UART interface
This is the default mode, in which the beacon receives input from the connected device via GPIO. You can imagine a button broadcasting its status (on/off) through the beacon.
In this configuration, the beacon will broadcast received data in the Estimote Telemetry packet. This means information about binary states of two GPIO pins. In other words, the beacon will be advertising two 0/1 values.
If you want to learn how to enable Estimote Telemetry, read:
What is a beacon protocol? Can beacons broadcast multiple packets simultaneously?
In the output mode, beacon delivers data to the connected device via GPIO. You could for example switch a LED lamp on or off with the beacon controlled from a mobile app.
In this configuration, the beacon will deliver data from two pins about their binary states to the connected device.
If you configure GPIO as an UART interface, you’ll be able to define custom advertising packets for an Estimote Beacon. This feature will soon be enabled in the SDK.
How do I access GPIO?
Estimote Beacons are equipped with 4 pin GPIO connector. The position of pins is marked by four dots on the side of a beacon’s enclosure. To connect, you need to puncture the enclosure with cable connector.
If you do not want to puncture the enclosure, you can remove the PCB through the Y-shaped opening in the beacon’s base.
Do Estimote Proximity Beacons and Estimote Stickers have GPIO?
No, GPIO is available only in Estimote UWB Location Beacons and Estimote Location Beacons.