PresTag
PresTag is a pressure logger. It samples barometric pressure and temperature on a fixed schedule and writes them to on-board flash, which makes it the family to reach for when the question is about altitude: how high a bird flew, when it climbed or descended, and how those episodes line up with the rest of a deployment.
It carries no accelerometer. A deployment that needs both altitude and activity is the BitPresTag’s job, which combines the two in one tag.
What it records
| Channel | Stored as |
|---|---|
| Barometric pressure | Absolute pressure in mbar |
| Temperature | Degrees C, from the pressure sensor |
| Supply voltage | Tag battery voltage over the deployment |
Samples are taken at the period set in the tag configuration before deployment, which is the main lever on how long a deployment lasts: a longer period costs resolution and buys time.
Hardware
The current design is the PresTagv3 board: an STM32L432KC processor, an ST
LPS27 pressure sensor, external flash, and an RV-3028 real-time clock. The
board designs live in the
hardware repository under
BoardDesigns/Tags/PresTag.
Firmware variants
Two builds share the same board and report the same tag type to the monitor, differing only in what they write:
- PresTag converts samples to engineering units on the tag and exports them as a pressure log.
- PresTagRaw exports raw sensor pages, converted on the host after download.
The build name and firmware string identify which one a tag is carrying.
Using one
PresTag is configured, armed and downloaded with the same tools as every other
family. In Tag Monitor it presents a schedule view; there are no additional
sensor controls to set. Downloaded data arrives as a SQLite file with
Pressure, Temperature and Voltage tables.