Eddystone Beacon – First look from the inside out

I got my hands on an Eddystone Beacon before its official release.

Eddystone Beacon – physical facts

• Dimensions and weight: 30 mm diameter, 10 mm thickness, 7 grams
• Promised lifetime: 18 months (30 year shelf life)
• Range: 75 Meters with up to 120 Meters at maximum power
• Enclosure: Waterproofed with an option for custom tooling
• Battery: Replaceable CR2032 3V Li battery

Inside the Eddystone beacon

Eddystone Beacon – sensors and interfaces

• Push button
• LED indicator
• Temperature sensor (option)
• Motion sensor (option)
• Light sensor (option)

Eddystone Beacon – legal stuff

• FCC
• IC
• CE
• RoHS
• Halogen free

Eddystone Beacon – from the inside

Eddystone beacon – antenna & ground plane

Inside the Eddystone Beacon is an inverted F antenna. On a closer look it is not just a copy of a common public antenna design. The F structure is not a straight line or a meander. It is a round curve in parallel to a round small round ground plane. Moreover, the antenna structure is not linear. It shrinks from top to the end.
The ground plane is as large as it can practically be inside the small BLE beacon. The metal battery holder is a part of the ground plane as well. Just open any BLE beacon you already own and compare it yourself. Open it if you can 😉 as Some BLE beacons are glued. It is a shame – if the beacon is glued it is impossible to replace the coin cell battery.

Eddystone Beacon – top and bottom view

Eddystone beacon inside

The BLE beacon is optimised for RF performance and price. The self-made interfered F antenna will save the cost of a ceramic chip antenna. The two black drops on the PCB save the cost of enclosing the integrated circuit. The production and test of two ICs is too expensive. This BLE beacon holds the semiconductor die directly on the PCB and the semiconductor die is bonded directly onto the PCB!
The plastic enclosure is split in two parts. The top of the enclosure is flexible and will form a perfect seal. As a result, this beacon is water-resistant.

Furthermore I can help you with the schematic diagrams of the Eddystone beacon. You can also take the source code and rework it to your own requirements. You are free to make a one-to-one copy, but you have no chance of producing it more cheaply.
If you are interested in samples in order to test this Eddystone Beacon, or in analysing another BLE beacon, or if your requirement is to analyse some other wireless IoT hardware, or if you are studying or developing of some kind of wireless IoT device, then do not hesitate to drop an email to harald.naumann (at) gsm-modem.de

Note: You can get the Eddystone beacon with other beacon profiles like the iBeacon format as well. As already mentioned earlier in this post – you can change the source code and protocol as you wish as it is an “open beacon format”.