Version 1.10 — July 2026 SpaceCommsKit — https://spacecommskit.com
The SCK-2400 is a 2.4GHz RF communications board built on OpenLST roots, using the Texas Instruments CC1352P SimpleLink wireless microcontroller. It replaces the SCK-915's OpenLST packet protocol with CCSDS framing — the same packet standard used by real spacecraft — while keeping the proven payload architecture from SCK-915: a Raspberry Pi Pico payload board running GPS, barometric altimeter, camera, and SD card flight logging.
With the SCK-2400 Ground Station you can:
Send and receive CCSDS commands between a ground station and a remote board over 2.4GHz RF
View real-time telemetry — uptime, RX/TX counters, link status
Update remote firmware over RF using OAD (Over-Air Download) — a full firmware image transfers in under 30 seconds
Query the payload board for GPS position, barometric altitude, and temperature
Trigger camera snapshots and manage files on the payload SD card
Note: The SCK-2400 operates in the 2.4GHz ISM band. Check local regulations for power limits in your jurisdiction before field or high-power operation.
| Item | Description |
|---|---|
| SCK-2400 Board ×2 | CC1352P-based 2.4GHz transceiver (one Ground Station board, one Remote board) |
| USB cables ×2 | Connect each board to your PC for programming and (GS board) operation |
| Antennas ×2 | 2.4GHz antennas |
| Raspberry Pi Pico payload board | Runs GPS, altimeter, camera, and SD logging (optional but recommended) |
| SCK Ground Station software | Windows application for commanding and monitoring |
The development hardware is SCK-2400 Mini boards (two units — one Ground Station, one Remote). Production hardware is the SCK-2400 custom PCB using the CC2652P.
Run the installer or build from source — see the SCK-2400 Developer Guide for build instructions.
Connect both boards to your PC via USB. Each LaunchPad exposes two COM ports — the lower numbered port (e.g. COM8) is the XDS110 debug/programming interface used by the Ground Station app.
Launch SCK Ground Station.
Quick Start Checklist:
0x010) to your PC via USBtlm_beacon response with a green checkmarkIf you see the green checkmark, your Ground Station board is alive and
the link is working. To talk to a Remote board over RF, set the APID
field to the remote board's address (e.g. 011) before sending commands
— the Ground Station board relays the command over RF automatically.
Connect via USB directly to your PC. This board must remain connected for the duration of your session — it relays all RF traffic between the Ground Station app and the Remote board.
This is the board that flies on your mission, or sits across the room during bench testing. It connects via RF to the Ground Station board and, optionally, via UART to a Raspberry Pi Pico payload board.
Remote board → Pico wiring:
| Remote Board Pin | Pico Pin | Function |
|---|---|---|
| DIO5 (header pin 10) | GPIO1 (pin 2) | UART TX → Pico RX |
| DIO16 (header pin 32) | GPIO0 (pin 1) | UART RX ← Pico TX |
| GND | GND | Common ground |
Both boards run on 3.3V logic — no level shifter is required.
| Component | Supply | Typical Current |
|---|---|---|
| SCK-2400 / LAUNCHXL-CC1352P-2 | 5V USB | ~100mA idle, higher during RF TX |
| Raspberry Pi Pico | 5V USB or 3.3V | ~25mA typical |
| BMP581/MS5611 altimeter | 3.3V | <1mA |
| GPS NEO-6M | 3.3V/5V | ~50mA |
The Home tab shows live telemetry from the connected and addressed board.
| Field | Description |
|---|---|
| Uptime | Seconds since last boot |
| RX Count | Packets received over RF |
| TX Count | Packets transmitted over RF |
| VCC | Supply voltage |
Telemetry updates each time you click Get Telem on the Commands tab, or automatically if the board's autonomous beacon is enabled.
Provides quick access to standard CCSDS commands.
| Button | Opcode | Description |
|---|---|---|
| Get Telem | 0x01 | Request telemetry from the addressed board |
| Reboot | 0x02 | Reboot the addressed board |
| Beacon ON / OFF | 0x04 | Enable or disable the autonomous RF beacon |
| Control | Description |
|---|---|
| Start OAD | Streams the built firmware image to the addressed remote board over RF |
| Inter-chunk delay | 10ms (production default) to 100ms — controls streaming speed |
| OAD Status | Query bytes received / total size during a transfer |
| Abort OAD | Cancel an in-progress transfer and clear the flash slot |
OAD performance: A full 335KB firmware image transfers in approximately 24 seconds at the 10ms setting — about 5% of a typical 8-minute LEO ground station pass, leaving ample time for acquisition and telemetry.
The remote board automatically reboots into the new firmware once the transfer completes and the image CRC is verified. If the connection is lost before verification, the board's bootloader (BIM) keeps the previous working firmware — OAD never bricks the board.
Lets you send any CCSDS command opcode with any payload. Commands persist
between sessions in customcommands.json.
Pre-loaded payload board commands:
| Name | Opcode | Payload | Expected Response |
|---|---|---|---|
| PICO Ping | 0x20 | — | PICO:ACK |
| PICO Read Temp | 0x21 | — | TEMP:13.47C |
| PICO Snap | 0x22 | — | SNAP:OK:snap_001.jpg:4617 |
| PICO List Files | 0x23 | — | LIST:snap_001.jpg,... |
| PICO Get GPS | 0x27 | — | GPS:lat,lon,alt,sats,fix,hpa,baro_alt,temp_c |
| PICO Get Baro | 0x28 | — | BARO:hpa,baro_alt,temp_c |
| PICO Beacon ON | 0x29 | 01 |
BEACON:ON |
| PICO Beacon OFF | 0x29 | 00 |
BEACON:OFF |
Tip: The Pico transmits its own GPS+baro beacon autonomously every 10 seconds. If your responses occasionally look mixed up or garbled, send PICO Beacon OFF first, run your commands, then send PICO Beacon ON when finished.
Displays live position from the payload board's GPS and barometric altimeter on an interactive map.
| Control | Description |
|---|---|
| Get GPS | Request a fresh GPS+baro fix on demand |
| Get Baro | Request barometric data only |
| Beacon ON / OFF | Toggle the payload board's autonomous 10-second beacon |
| Clear Track | Clear the plotted flight track from the map |
| Export KML | Save the current track as a KML file for Google Earth |
| Record | Begin recording a flight session to disk |
| Replay | Play back a previously recorded flight session |
The map shows current position, altitude, ascent rate, GPS/baro altitude delta, and satellite fix status — updated live as beacon packets or on-demand GPS responses arrive.
A file manager for the payload board's SD card.
Before using the Files tab: send PICO Beacon OFF to prevent the autonomous beacon from interrupting file transfers.
A typical flight log (.sckflight) or small JPEG transfers in a few
seconds depending on RF conditions and file size.
Used to build, sign, and flash custom firmware for either board.
sck2400_firmware CCS project folderSet Board Role — Ground Station (APID 0x010) or Remote (APID 0x011, 0x012, ...)
Choose RF Power Mode — Bench (0 dBm, indoor/safe) or Max Power (field/HAB/LEO mission)
Click Clean + Build
Always use Clean + Build after making source code changes. Stale object files are the most common cause of mysterious firmware behavior.
After flashing, send 2–3 Get Telem commands before moving the board to remote RF operation to confirm the radio stack is healthy.
One-time setup for new boards — flashes the bootloader (BIM) and sets the board's APID (address). BIM is permanent after initial flashing and is never overwritten by subsequent application or OAD updates.
Confirm the board is connected via USB (RF boards need external power for sustained TX in field deployments)
Rapid LED double-blink pattern indicates the bootloader is running without a valid application — reflash the application firmware
Confirm the Ground Station board (0x010) responds first — it relays RF commands
Boards should be at least a few feet apart during bench testing to avoid RF saturation
Try Get Telem 2–3 times — the first packet after boot is sometimes missed while the RF synthesizer stabilizes
Confirm the Pico is running main.py and showing beacon output on its
serial console
Verify UART wiring: Remote board DIO5 → Pico GPIO1, DIO16 → Pico GPIO0
If a transfer fails partway through, the Ground Station automatically retries — re-erasing the flash slot and re-streaming
A failed or interrupted OAD never corrupts the running firmware — BIM always falls back to the last known-good image
Confirm you flashed the merged hex (application + BIM), not the application-only hex — the Ground Station does this automatically via Build + Flash
A rapid 1-flash-pause-3-flash LED pattern after reset usually indicates BIM is running without a valid application image
| Parameter | Value |
|---|---|
| RF Frequency | 2.4GHz ISM band |
| Microcontroller (dev) | Texas Instruments CC1352P1F3RGZ (LAUNCHXL-CC1352P-2) |
| Microcontroller (production) | Texas Instruments CC2652P1FRGZ |
| RTOS | TI-RTOS7 |
| Protocol | CCSDS Space Packet Protocol |
| OAD transfer (335KB image) | ~24 seconds @ 10ms inter-chunk delay |
| Cold boot time | <40ms |
| Interface | USB (XDS110), 921600 baud to Ground Station |
| Payload UART | 115200 baud, ESP framing, to Raspberry Pi Pico |
SpaceCommsKit SCK-2400 User Guide v1.10 For updates and source code see https://spacecommskit.com