Technical Specifications

This section provides detailed technical specifications for the SatTracker device.

Hardware Specifications

Processor and Memory

SoC:

Espressif ESP32-S3 (dual-core, 240 MHz)

PSRAM:

8 MB OPI (octal) PSRAM

Flash:

8 MB or 16 MB (variant dependent)

Wireless Connectivity

WiFi Standard:

IEEE 802.11 b/g/n

Frequency Band:

2.4 GHz only (5 GHz not supported)

WiFi Modes:

Station (STA), Access Point (AP)

Security:

WPA, WPA2, WPA2/WPA3 mixed

Antenna:

On-board PCB antenna

Note

SatTracker does not contain a radio receiver or transmitter for the amateur bands. It predicts and displays; you operate the satellite with your own station.

Display

Type:

7-inch IPS colour LCD (RGB parallel)

Resolution:

800 x 480 pixels

Backlight:

White LED (dimmable on supported hardware)

Touch Panel:

Capacitive multi-touch

Surface:

Glass

Power Requirements

Input Voltage:

5 V DC ±5% (via USB-C)

Input Current:

500 mA typical, ~1 A peak

Power Consumption:

2–4 W typical

Connector:

USB-C

Battery Support:

Via USB-C power bank (not included)

Warning

Use only a quality 5 V USB-C power supply rated for at least 1 A. Insufficient power may cause boot loops, display flicker, or instability.

Physical Specifications

Form factor:

7-inch landscape tablet-style enclosure

Mounting:

Desktop or shelf; supports 180° screen rotation for inverted mounting

Environmental Rating:

Indoor use only

Operating Environment

Operating Temperature:

0 °C to 40 °C (32 °F to 104 °F)

Storage Temperature:

−20 °C to 60 °C (−4 °F to 140 °F)

Humidity:

20% to 80% RH non-condensing

Altitude:

Up to 2000 m

Tracking Specifications

Orbit Model:

SGP4 / SDP4 (near-earth and deep-space)

Satellites in Catalogue:

About 95 (CelesTrak amateur radio group)

Workable Satellites with Frequency Data:

33 (firmware 0.1.0)

Tracked Satellites:

Up to 12 at once

Prediction Horizon:

24 hours, up to 12 passes per satellite

Prediction Accuracy:

within about 1 s (AOS / TCA / LOS) and 0.05° (maximum elevation) of the reference implementation, for the same orbital data

Position Update Rate:

1 per second

Pass Recalculation:

every 15 minutes, and on any change of data, location or settings

Horizon Mask:

0°, 5°, 10° or 15°

Doppler Correction:

live, for uplink and downlink, from the range rate

Map and Display

Map Projection:

Equirectangular (plate carrée), whole Earth

Map Area:

560 x 280 pixels

Coastlines:

Natural Earth 1:110m

Day/Night:

Solar terminator with grey-line (civil twilight) band, full resolution, updated every minute

Pass Timeline:

12 hours (1 h past, 11 h ahead), one row per tracked satellite

Themes:

NEON, OPS

Alerts

Good-Pass Threshold:

10°, 20°, 30°, 45° or 60° maximum elevation

Alert Lead Time:

2, 5, 10, 15 or 30 minutes before AOS, plus at AOS

Alert Output:

On-screen banner; wakes the screen from night mode

Network Specifications

Supported Protocols

Orbital Data:

HTTPS (TCP port 443) to celestrak.org

Firmware Updates & Registration:

HTTPS (TCP port 443) to u.topbytes.net

Web Setup Page:

HTTP (TCP port 80, AP setup mode only)

Time Sync:

NTP (UDP port 123)

DNS:

UDP port 53

Orbital Data

Source:

CelesTrak GP data, amateur radio group, TLE format

Refresh:

Daily (retry every 15 minutes on failure)

Storage:

Flash file system; firmware-built-in fallback

Time Synchronisation

Protocol:

NTP (Network Time Protocol)

Servers:

pool.ntp.org, time.google.com

Timezone:

Configurable (18 worldwide zones, automatic DST)

Clock Display:

Local HH:MM:SS with zone, plus UTC HH:MM

Configuration Limits

Max WiFi Networks:

3 (priority-ordered)

Max Tracked Satellites:

12

Brightness Range:

10–100% (dimmable hardware)

Performance Specifications

Cold Boot:

~2 seconds to UI ready

WiFi Connection:

5–30 seconds (network dependent)

NTP Sync:

1–3 seconds after WiFi

First Predictions:

about 10 seconds after the time is set

Watchdog Timer:

Yes

Automatic Recovery:

WiFi disconnections, failed downloads

OTA Failure Handling:

Failed updates leave the running firmware untouched

Compatibility

WiFi Router Compatibility

Compatible With:

  • All 2.4 GHz 802.11 b/g/n routers

  • WPA / WPA2 / WPA2-WPA3 mixed

  • Most home and portable routers (including phone hotspots)

Not Compatible With:

  • 5 GHz only networks

  • WPA3-only networks (use WPA2/WPA3 mixed-mode)

  • Enterprise WiFi with 802.1X

  • Captive portals requiring web-form authentication after joining

Power Source Compatibility

Compatible With:

  • USB-C wall adapters (5 V, ≥1 A)

  • USB-C ports on computers

  • USB-C power banks

  • USB-C car chargers

Not Recommended:

  • Charge-only USB-C cables (won't expose the serial console)

  • Supplies under 1 A — display flicker likely

Data Sources

  • Orbital elements: CelesTrak

  • Transmitter data: TopBytes curated list and SatNOGS DB (CC BY-SA 4.0)

  • Coastlines: Natural Earth (public domain)

  • Fonts: Exo 2, Orbitron, Share Tech Mono, IBM Plex Sans Condensed and IBM Plex Mono (SIL Open Font License)

These are independent sources not affiliated with TopBytes Ltd.

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