ZeroTrace Echo
Hardware
The Echo hardware at a glance, radio, memory, power, storage and what is optional.
Hardware
Echo pairs an ESP32-S3 processor with a dedicated sub-GHz radio, on a keychain-sized board with USB-C charging, one colour status light and one button.
| Processor & memory | |
|---|---|
| Processor | ESP32-S3 (dual-core, 240 MHz) |
| On-board memory | 2 MB |
| Storage | 10 MB usable capture storage |
| Sub-GHz radio | |
| Radio | TI CC1101 sub-GHz transceiver |
| Tuned band | 410-450 MHz (front-end module) |
| Wider tuning | 300-348 / 387-464 / 779-928 MHz (reception only, reduced sensitivity outside the tuned band) |
| Default frequency | 433.92 MHz |
| Output power | Up to +10 dBm |
| Modulation | OOK/ASK and FSK |
| Power | |
| Battery | 1x 3.7 V Li-ion / LiPo, 2-pin JST-XH (2.5 mm) connector, user-supplied |
| Charging | USB-C, on-board |
| Charge indicator | Dedicated red / green charge lights |
| Interface | |
| Control | ZeroTrace mobile app over Bluetooth LE |
| Connectivity | Bluetooth LE; USB-C |
| Local controls | 1 RGB status light + 1 button |
Frequency range
Echo's front end is tuned for the 410-450 MHz band, where most gate, garage and sensor traffic lives. The radio can also receive across the wider ranges listed above; signals outside the tuned band still come through, but more weakly, and Echo flags them as weak so you know.
Local controls
The only controls on the device are one colour status light and one button. Two extra lights show charge state. Everything else, setup, capture and decode, happens in the app over Bluetooth LE.
Battery & connector
Echo runs from a single 3.7 V Li-ion / LiPo cell that plugs into a 2-pin JST-XH connector — 2.5 mm pitch, and charges over USB-C. It ships without a cell, so you fit your own.
This is the JST-XH (2.5 mm) family, not the JST-PH 2.0 mm that most hobby LiPo packs use — a PH plug will not fit. Buy a pack terminated in a 2-pin JST-XH plug, or re-terminate to XH (measure the pin spacing: 2.5 mm = XH, correct; 2.0 mm = PH, wrong). Even with the right connector, a plug that fits can still be wired backwards, so treat polarity as something to verify, not assume.
Before plugging the battery in, check the + and − printed on the board next to the connector and confirm the pack's wires match (red is normally +, black is −). If they do not line up, re-pin the plug or use a correctly wired pack. Reversed polarity can permanently destroy the board.
Recommended cell
A good fit is a 3.7 V single-cell (1S) LiPo of around 3000 mAh with a built-in protection board. This exact cell is sold across Amazon regions under several names, MakerFocus, YELUFT, and often listed as a "Meshtastic Node" or Meshnology battery, but it is the same pack everywhere:
Its dimensions are roughly 65 × 35 × 10 mm (cell body) with about a 55 mm lead, and it is rated 3.7 V / 3000 mAh (11.1 Wh). Check this footprint against the space you have before buying.
The cell above comes terminated with a JST 1.25 plug, which does not fit Echo's 2-pin JST-XH (2.5 mm) header. The cell itself is ideal, but you must re-terminate the leads to a 2-pin JST-XH plug (or swap the connector) before use. When you do, keep the polarity correct, match red to + and black to − as printed on the board. Do not force the 1.25 plug or use an adapter that reverses the wires.
What is optional vs onboard
- Battery is user-supplied. Echo ships without a cell; you fit your own Li-ion / LiPo on the 2-pin JST-XH (2.5 mm) connector, not the common JST-PH 2.0 mm. On-board USB-C charging is included.
- No onboard GPS. Echo has no GPS receiver. Wardriving uses your phone's location instead. There is no add-on that gives Echo its own positioning.
- No memory card. Captures are kept in Echo's built-in 10 MB storage; there is no memory-card slot.
- Sub-GHz antenna. The radio module carries the antenna connection, with an SMA external antenna.