MultiNav Pro+ BLE - does output power scale down automatically at short range?

Jennifer Williams•June 23, 2026

Been working on a wearable tracking project where the BLE module will sometimes be operating at like 5-10 meters from the base station, sometimes much further out depending on the deployment scenario. The 50km range spec is obviously overkill for the close-range cases, but what I'm wondering is whether the module does any kind of adaptive power management on the RF side - like does it automatically reduce TX power when the RSSI is strong, or is it always blasting at full output regardless of link quality?

💬 5 replies👍 0 likes👁 0 views

Replies

Adam•June 23, 2026

@Jennifer Williams good question — the honest answer is that the MultiNav Pro+ doesn't do automatic adaptive TX power out of the box. It's running at its configured output level regardless of what RSSI looks like on the link. The module is built around the STM32WB07 and the external PA stage, and that PA isn't being dynamically throttled based on link quality in the current firmware.

That said, you're not stuck blasting full power at 5 meters. TX power is configurable in firmware, so for your wearable use case you could either set a fixed lower power level if you know the deployment is always going to be short range, or build a small control loop in your application layer that reads RSSI and adjusts TX power through the BLE stack — the STM32WB07 supports that. It's not automatic, but it's not hard to wire up either.

The AI firmware builder in the Dev Hub is actually pretty decent at scaffolding something like this if you describe the logic — something like "read RSSI every N seconds, step TX power down if above threshold X, step it back up if below threshold Y" — it'll get you most of the way there without writing it from scratch.

David Moore•June 23, 2026

The MultiNav Pro+ doesn't do automatic TX power scaling based on RSSI out of the box - it'll just run at whatever power level you've configured. You can absolutely manage this yourself though by reading RSSI periodically and stepping the TX power down via the AT command set, which is honestly what I'd recommend anyway since you get more control over the tradeoff between range and battery life for your specific deployment scenarios.

William Thomas•June 23, 2026

David's right, and worth adding that if you're bouncing between 5m and long range deployments you might want to just set a few fixed power tiers and switch between them based on RSSI thresholds rather than trying to do anything continuous - way easier to tune and debug in the field. I've been doing something similar on a project and it's been rock solid once you get your thresholds dialed in.

Richard Rodriguez•June 23, 2026

Yep tiered approach is the way to go - also worth factoring in that keeping TX power high at short range can actually cause issues with some receivers getting overwhelmed, so there's a functional reason to step it down beyond just battery savings. I'd start with maybe 3 tiers and give yourself some hysteresis on the thresholds so you're not toggling back and forth constantly if the RSSI is sitting right on a boundary.

Thomas Taylor•June 23, 2026

Richard's point about receiver saturation is real - burned some time on that exact issue before I figured out what was happening. Hysteresis is definitely not optional if your RSSI has any normal fluctuation, I'd go at least 5-6 dBm of headroom on each threshold boundary or you'll be toggling constantly.