I'm trying to implement a Bluetooth (BLE) gateway into a project to transfer data between hardware and a mobile device with an application. The hardware is not unique, it could be mass produced with the controller having the same program flashed into it.
If 100 of the hardware product is made, powered up sitting side by side, what is the best way to set up the information that the BLE broadcasts to advertise so that it can be received by a mobile device, and only 1 hardware and mobile device can be connected at any time.
For example, if you have 3 of the same fitness tracking watches side by side, and you only want to connect to 1 of them, how do you distinguish which is which on say the phones bluetooth pairing menu. Does each of the manufactured hardware need to have a unique ID that shows on the mobile device (eg ABC11, ABC112, ABC113 etc), and how do you program 100 unique programs into the hardware quickly. On the other hand, should each of the hardware have the same ID broadcast, and then the user just hopes for the best if the correct hardware is paired.
(BTW, the hardware is an arduino based microcontroller using a BM70 BLE module. neither of which are intended to be modified by the user)
Assistance appreciated. Thanks. Nunya
You do not have to manually program a different MAC addresses for each device, the BM70 module is the one that provides the BLE MAC address and they are supposed to have unique ones. Sometimes manufacturer recycle (reuse) the addresses, but I think the chance to hit a MAC twice with 100 devies is pretty low.
If your devices are all the same and use the same program they all offer and advertise the same BLE service. The service and containing characteristics are the feature that distinguishes your devices from other BLE devices. A true BLE device that does not also use Bluetooth Classic will not show up in your phones bluetooth settings or pairing menu. BLE requires a dedicated app where you scan for BLE devices and idealy filter for the special service you are using to only find your own devices.
To distinguish between 100 devices placed next to each other (if this even matters since they are all the same) you need to either read the MAC address and prit it on a label for each device or use some status LEDs to show the connection status on your arduino. If you connect to one device the LEDs could start blinking to show which device you are connected to.