When building portable sensors we often want to calibrate and double-check their readings before allowing them to log data remotely. Whilst developing these we can easily SSH into them and write any results to screen. However what happens when we are in a very remote part of the world, with no laptop, wifi or signal?

Within this tutorial, we look at exploiting the Bluetooth capabilities of a Raspberry Pi Zero (without WiFi) to transmit the initial set of results to a handheld device of our choosing. In our case, it will be through the use of a mobile phone or android tablet, such that we can compare the sensor and GPS readings.

Installation and Setup

Before we start there are a couple of changes required for the Bluetooth to work. These are outlined below.

Configuring the device Bluetooth

We begin by changing the configuration of the installed Bluetooth library:

sudo nano /etc/systemd/system/dbus-org.bluez.service

Here we locate the line starting ExecStart , and replace it with the following:

ExecStart=/usr/lib/bluetooth/bluetoothd --compat --noplugin=sap
ExecStartPost=/usr/bin/sdptool add SP

Having added the ‘compatibility’ flag, we now have to restart the Bluetooth service on the Pi:

sudo systemctl daemon-reload;
sudo systemctl restart bluetooth.service;

#big data

Sending data from a Raspberry Pi Sensor unit over Serial-Bluetooth
2.05 GEEK