Inside every Bluetooth sensor beacon is a System on a Chip (SoC) that’s a small computer that runs code. Dialog Semiconductor, the manufacturer of the SoC in some beacons, has just announced the world’s smallest (2.0mm x 1.7mm) and most power-efficient Bluetooth 5.1 SoC the DA14531.
The high level of integration means it only needs six additional electronic components and a power supply to make a complete Bluetooth low energy system. It’s expected to bring SoCs down to $0.50 in high volume.
While beacons tend to be limited by battery size rather than SoC size, the reduced price might bring downward pressure on cost. The small size is of more use in power harvesting/wearable scenarios such as printed Bluetooth sensors, connected injectors, glucose monitors and smart patches.
The type of System on a Chip (SoC) can greatly affect beacon battery life. At one time it was only Dialog that had low power SoCs. TI, NXP and Nordic followed and now Toshiba has joined them with their new TC35678FSG, TC35678FXG and TC35679FSG (PDF).
Toshiba has more information on these products.
The BeaconZone store has a special category for low power SoC beacons.
We have the new ASensor beacon in stock. This is our smallest sensor beacon measuring only 37.3mm x 37.3mm x 7mm and it uses the power efficient Dialog DA14580 that gives up to 1.5 years from a CR2025 battery.
The beacon supports iBeacon, Eddystone or sensor advertising. For sensor mode, the temperature, acceleration and battery level are in the advertising data.
We now have a few samples of the new TON9218 solar powered beacon available. The large 6.5cm x 9.6cm solar panel keeps the on-board rechargeable LIR2032 battery charged using only normal indoor lighting. Even with weak light, the solar panel generates about 100uA that’s 5x the average current consumption. Hence, with the use of the rechargeable LIR2032 battery as backup, this beacon can work almost forever.
As with the other Iotton models, the beacon has an internal timer and uses the Dialog DA14580 that provides 2x to 3x battery life of Nordic nrf51822 based beacons and up to x6 the battery life of TI CC254x based-beacons.
One of our most popular beacons is the TON9108. The low price has made it popular with first timers who want to try out iBeacons without a large financial commitment. It’s also great for rollouts because the low power Dialog DA14580 and timed on period allows the CR2032 battery to last as long as a CR2477 in a comparable TI CC254x based-beacon.
We recently re-stocked in larger quantities and so have been able to lower the price and keep it our March “Most Affordable Beacon”. This beacon is currently only £7.70 + vat (about $11, €9). EU companies outside the UK can order ex vat.
You can find the processor chip in the specification section of our beacon descriptions. Most people don’t know what this means or implies. This article will hopefully help you make a more informed choice and provide some insights into what’s coming in the near future.
There are currently three main chip families from Texas Instruments (CC254x), Dialog (DA14580) and Nordic (nrf51822). These chip manufacturers publish standard electronic circuit and printed circuit board layouts that beacon OEMs use for their beacons. Hence, most beacons, within a chip family, have very similar designs. However, small differences in implementation of board layout in areas such as the power supply, grounding, terminations, connectors and the antenna can cause electrical differences that can cause loss of power or noise that can affect operation. Hence the quality of the beacon radio signal is affected more by the quality of the implementation than the choice of chip. This is also evident in real world tests. We have performed RSSI strength and stability tests on the beacons we sell and haven’t yet found any correlation between signal quality and chip family.
The CPU type does significantly affect battery use. For the same transmit power and advertising interval configuration, the Dialog DA14580 provides 2x to 3x battery life of Nordic nrf51822 based (e.g. Estimote) beacons and up to x6 the battery life of TI CC254x based-beacons.
However, chip families are evolving ecosystems and there are also new contenders. In our talks with manufacturers, we know that the newer TI CC2640 is being used in new beacon designs and will provide a x3.5 battery life, at a compromise of a slightly reduced signal range, compared to the CC254x. NXP (used be part of Philips Semiconductors) also have the QN9020 that provides x3.5 battery power compared to the TI CC254x. We’ll be stocking beacons with these new processors in the near future.