OnAirDecode ANT+ sensors with an SDR
ANT+ sensors on 2457 MHz (and other ANT networks on their own channel): heart rate straps and watches, bike speed, cadence and power sensors, footpods, environment sensors, as a watch or bike computer hears them: 1….
- Group
- IoT & sensors
- In the mode list
- ANT+ sensors on 2457 MHz (and other ANT networks on their own…
What ANT+ sensors is
ANT+ is the low-power wireless protocol of many heart-rate straps, bike sensors, power meters and fitness watches, on 2457 MHz.
Frequencies and settings
2457 MHz (ANT+), or any ANT channel 2400 - 2524 MHz, 4 Msps (a radio that reaches 2.4 GHz).
| Tuning range of the mode table | 2400 to 2524 MHz |
|---|---|
| Sample rate asked | 4 Msps |
| Lowest working rate | 4 Msps |
| Channel width | 2 MHz |
OnAir takes any frequency you type; the numbers above are the mode's starting point and the range its table describes. In the app the shortcut label is ANT+ sensors on 2457 MHz (and other ANT networks on their own….
What OnAir shows
Heart rate straps and watches, bike speed / cadence / power sensors, footpods and environment sensors: device number and type, the data pages (heart rate with beat count and R-R interval, plotted over time; power, cadence, speed, temperature), manufacturer, serial and battery. Receive only: the open broadcasts a watch hears, nothing is sent or paired.
Limits and what it was checked with
Checked with generated signals and impairments; recordings of real signals welcome.
Which radio you need
This mode sits at a high frequency, so check that your radio tunes it: a HackRF covers 1 MHz to 6 GHz, and RTL-SDR stops near 1.7 GHz. Some modes at these frequencies also need a fast radio (10 to 20 Msps) or a dish and an LNB.
Receiving and the law
Questions about ANT+ sensors
Can I decode ANT+ sensors with an RTL-SDR?
No: this mode needs a radio that samples at 4 Msps or more, and an RTL-SDR reaches about 2.4 Msps.
Is it legal to receive ANT+ sensors?
This mode is passive. It only receives, never connects, pairs or joins networks, and never decrypts payloads. Check the rules where you live.
Can I try ANT+ sensors in OnAir without a radio?
Yes. Most modes include a built-in synthetic test signal, so you can open the screen and try the controls before you own a radio.