RE: iBeacon emulator without SDK

ovrebekk — Thu, 17 Sep 2020 12:47:09 GMT

Did you start the external HF crystal before starting the advertising?

The 32MHz HF crystal is disabled by default, and if you don't enable it the radio will not transmit on the correct frequency.

Best regards
Torbjørn

RE: iBeacon emulator without SDK

honestech74 — Tue, 15 Sep 2020 15:30:52 GMT

Hi, ovrebekk
I am sorry for the late reply.

I already got started from your linked example but didn't get a good result.
But I think you answered as you can.
If you can suggest any better example, I'll like 🙂

Thank you

RE: iBeacon emulator without SDK

ovrebekk — Wed, 02 Sep 2020 08:13:35 GMT

The green area is the HCI header, and you can find the full description at page 2382 of the Bluetooth 5.2 specification (Vol 4, Part E, Section 7.7.65.2).

0x04 marks this as an HCI event.
0x3E is the event code shared by all LE events.
0x2A is the length of the packet
0x02 marks this as an advertising report event
0x01 is the number of responses in the event
0x00 means it is a connectable and scannable undirected advertising packet (ADV_IND)
0x01 mean the device is using a random device address

And the final 0xB4 at the end of the packet is the RSSI value.

While you can use one device to simulate multiple beacons, one thing this will not allow you to simulate is how real beacons will have independent timing, and will at times get into timing conflicts where two or more beacons send data at the same time.

In order to simulate this behavior you need to use multiple beacon emulators, but at a minimum you can use this method to simulate more beacons than you would otherwise be able to.

While we don't have an official example showing how to implement a beacon from scratch, I would suggest having a look at hal_radio.c from the solar panel beacon example on Github:
https://github.com/NordicPlayground/solar_sensor_beacon/blob/master/src/hal_radio.c#L89

The function l linked to will set up the radio to be compatible with BLE, including the access address used for Bluetooth advertise packets.

Best regards
Torbjørn