Last week we published a detailed guide to the SenseID evaluation boards — five battery-free sensor tags that communicate via EPC C1G2. This week we cover the other side of the same platform: the SenseBLE family.
The headline: same sensors, same energy harvesting, different communication protocol. SenseBLE tags harvest energy from a UHF RF field (exactly like SenseID), power up the sensor, take a measurement — and then transmit the data via a BLE advertising burst at 2.4 GHz instead of using EPC C1G2 backscatter.
The result: any BLE-capable device can receive the sensor data. Your phone. A tablet. A 20 € BLE gateway. No UHF RFID reader required on the data path.
1) The SenseBLE lineup
Four evaluation boards are available today, mirroring the core SenseID lineup:
EVAL‑SBLE‑AT — Ambient temperature. Same digital temperature sensor as the EVAL-SID-AT. Measures air temperature around the tag.
EVAL‑SBLE‑RHAT — Relative humidity and temperature. Same combined RH + T sensor as the EVAL-SID-RHAT. Measures both humidity and temperature in a single tag.
EVAL‑SBLE‑ACC — 3-axis accelerometer. Same MEMS accelerometer as the EVAL-SID-ACC. Measures acceleration along X, Y and Z axes for vibration, tilt, shock and orientation.
EVAL‑SBLE‑MGF — Magnetometer. Same 3-axis magnetometer as the EVAL-SID-MGF. Measures magnetic field for position detection, tamper detection and proximity sensing.
All boards: 50 € each, standard dipole PCB antenna, compatible with KL-OSIRIS.
2) What’s the same as SenseID
The sensor. Identical hardware, identical calibration, identical accuracy. A temperature reading from an EVAL-SBLE-AT and an EVAL-SID-AT in the same location will show the same number.
The energy source. Both families harvest energy from a UHF RF field in the 868/915 MHz band. The tag doesn’t care whether that field comes from a commercial RFID reader or a dedicated RF transmitter — it just needs enough energy to power the sensor and the communication circuit.
The operational range. The distance at which the tag can operate is limited by the UHF power transfer, not by the communication protocol. Since both SenseID and SenseBLE use the same energy harvesting front end, their working range from the RF source is essentially the same.
The price. 50 € per evaluation board for both families.
3) What’s different
Communication protocol. SenseID sends data via EPC C1G2 backscatter (modulating the incoming RF signal and reflecting it back at 868/910 MHz). SenseBLE sends data via a BLE advertising burst (an active transmission at 2.4 GHz). Both carry the same payload: tag ID plus sensor measurement.
Read pattern. This is the most important practical difference. With SenseID, the reader controls when each tag is interrogated — it sends a command, the tag responds. This is deterministic: you know exactly when you’ll get a reading. With SenseBLE, the tag accumulates energy from the UHF field and then fires a BLE burst when it has enough. This is event-driven: the tag decides when to transmit, based on energy availability. You’ll see the data arrive in bursts, not on demand.
What can receive the data. SenseID requires a UHF RFID reader. SenseBLE can be received by anything that understands BLE advertising packets — smartphones, tablets, BLE gateways, IoT edge devices, laptops with BLE adapters. This dramatically expands the receiver options and typically lowers the receiver cost.
Receiver-side cost. This is where the economic argument lives. A UHF RFID reader needs complex same-band TX+RX electronics (as we discussed in our economics post). A BLE gateway is commodity hardware. If you’re building from scratch with no existing RFID infrastructure, the SenseBLE path can be meaningfully cheaper on the receiver side.
4) Evaluating SenseBLE: what you need
A UHF energy source. This can be a commercial UHF RFID reader (you’re using it purely as an RF power source — its RFID functionality isn’t needed for SenseBLE) or a dedicated RF transmitter. If you already have an RFID reader from evaluating SenseID, use the same one. The tag harvests the energy regardless.
A BLE receiver. The easiest option: your smartphone with a BLE scanner app (nRF Connect, LightBlue, or similar — all free). You’ll see the SenseBLE tag appear as an advertising device with the sensor data in the advertising payload. For a more structured evaluation: KL-OSIRIS on a computer with BLE capability.
That’s it. The barrier to entry is genuinely low. If you have a UHF RFID reader or transmitter and a phone with BLE (so, any modern phone), you can evaluate SenseBLE right now.
5) The evaluation experience: what to expect
Bursts, not continuous reads. When you place the SenseBLE tag in the UHF field, it starts accumulating energy. After enough energy has been stored, the tag powers the sensor, takes a measurement, fires a BLE advertising burst, and goes back to sleep. Then the cycle repeats. On your BLE scanner, you’ll see the tag appear and disappear — that’s normal. Each appearance is a fresh measurement.
Burst frequency depends on field strength. Close to the RF source (4-5 meters), the tag accumulates energy quickly and bursts might come every second. At longer distances, the energy accumulation takes longer and bursts are less frequent. If you move the tag to the edge of the power transfer range, bursts might take 10-15 seconds or more. This is physics, not a problem — but it’s different from the instant response you get with SenseID.
The advertising payload contains the data. The tag ID and sensor measurement are encoded in the BLE advertising packet. KL-OSIRIS decodes this automatically and displays the reading on screen. If you’re using a generic BLE scanner app, you’ll see the raw advertising data — you’ll need to know the payload format to interpret it (documented in the evaluation board datasheet).
Test range from both sides. You have two “ranges” to consider: the distance from the UHF source to the tag (power transfer range) and the distance from the tag to the BLE receiver (BLE advertising range). The power transfer range is the bottleneck — BLE advertising typically reaches much further than the UHF energy can be harvested.
6) SenseID or SenseBLE — a quick recap
If you’ve read both evaluation guides and you’re still wondering which to buy, here’s the practical summary:
Buy SenseID if you already have a UHF RFID reader, you want deterministic reads, or your systems already handle EPC C1G2 data.
Buy SenseBLE if you don’t have an RFID reader, you want to evaluate with just a phone, you’re planning a greenfield deployment where BLE gateway cost matters, or your IoT platform already speaks BLE.
Buy both if you want to compare the two approaches side by side. The sensor data will be identical — only the delivery method changes. This is actually a very useful evaluation: it lets you make the protocol decision based on direct experience rather than specs.
7) From evaluation to custom solution
Like the SenseID boards, these are evaluation tools — not production-ready tags. The path forward is the same: validate the concept with a 50 € board, and if the technology fits your application, we’ll discuss a custom solution designed for your specific environment, sensor requirements, and form factor.
The SenseBLE architecture is particularly interesting for custom solutions where the receiver infrastructure needs to be cost-optimised. If you’re deploying at scale across many zones, the combination of a dedicated RF transmitter (for power) plus commodity BLE gateways (for data) can deliver significant savings compared to a UHF RFID reader per zone.
Order evaluation boards: SenseBLE product page — all boards 50 €.
Download KL-OSIRIS: Resources page — free, works with both SenseID and SenseBLE.
Ready to discuss a custom solution? Contact us — we’ll help you decide which protocol fits your deployment and design the right solution.
Next week: “SENSEID SDK: Building Custom Applications in .NET and Python” — for developers who want to integrate sensor data into their own systems.