TinyGS :: 2.4 GHz LoRa (low cost and low tech) ground station

Project to develop a ground station board that will receive messages from satellite on the 2.4GHz band. Satellite tracks are Thingsat@STORK1 and other cubeseat followed by the TinyGS community. This station is low cost (off the shelves boards and modules) and low tech (required only a solder iron).

This Git contains Hardware and software of a TinyGS 2.4 GHz LoRa ground station https://tinygs.com/.

ESP32 Wroon 32U

The default MCU board is the ESP32 Wroom 32U.

Remark: The ESP32 Wroom 32D (on board PCB antenna) and The ESP32 Wroom 32U (UFL connector for an mandatory external antenna) can be used.

SX1280 modules

For the long-range communication, we will use the Semtech SX1280, which is a low power 2.4 GHz LoRa RF Transceiver.

Several manufacturers provide RF modules integrating the SX1280 transceiver :

Project contains several PCBs and firmwares.

Main Board

PCB are made to integrate up to 2 Mikrobus modules including SX1280 technology. Mikrobus board is an add-on board socket standard made by mikroe. This makes the ground station adjustable and modular.

There are 2 different PCB version:

Board_Tinysgs_2.4GHz_V1, which contains: ESP32 Wroom 32 + 2 Mikrobus modules + Grove connectors (RXTX,I2C,ANA)
Board_Tinysgs_2.4GHz_V2, which contains: ESP32 Wroom 32 + 2 Mikrobus modules + Grove connectors (RXTX,I2C,ANA) + H-Bridges for driving stepper + Power supply

We made the board as modular as possible. It is possible to implement all modules as desired, as long as it respects the Mikrobus pin specification. Mikrobus module are connected by SPI, I2C, UART and more GPIO. They are both supplied by 3V and Mikrobus_1 is also supplied by 5V if desired. 2 SMA connector mount edge are available on board. Theyre a connected to a SMA male connector, which allows to plug any signal that we want through a SMA female connector.

Both Mikrobus boards are connected to the ESP 32 by SPI. They are using the same SPI bus (SPI_0).

PCB are made on KiCad, which is a free software for electronics circuit board design. PCBs has been manufactered by JLCPCB.

Power

A Power Bank NCR18650B Battery shield made for Arduino and ESP32 can be plugged under the board using the 4 screw holes.

Mikrobus adapters for SX1280 modules

The design of two Mikrobus adapters for SX1280 modules are currently provided by the project:

The pinouts of those adapters have some differences.

Two versions of the E28 module exists: 12S & 20S

EByte28 module
AN  <-> Busy
INT <-> DIO1
PWM <-> DIO2

Lambda80C module
AN  <-> DIO1
INT <-> Busy
PWM <-> DIO2

NiceRF SX1280 TCXO module
AN  <-> ??
INT <-> ??
PWM <-> ??

Other Mikrobus adapters for SX1280 modules

Other Mikrobus modules (for the second Mikrobus slot)

Have a look into the shop

Geditech's LoRa Microchip RN2483 (for 433 MHz and 868 MHz ISM bands)

Firmware

Firmware are into ./Firmware.

Off-the-shelves gateways for LoRa 2.4 GHz

Those gateways had 3 LoRa® 2.4GHz channels for Rx and 1 LoRa® 2.4GHz channels for Tx.

Multitech MTCDT + MCard MTAC-LORA-2G4-3
SX1280Z3DSFGW1 LoRa® 2.4GHz 3 Channels Single SF Reference Design (included a removable mPCIe card).
Embit EMB-FEM2GW-O-2G4 (included a removable mPCIe card EMB-LR1280-mPCIe-4x).

References

Buy

ESP32 Wroon 32U

Important: ESP32 Wroon 32U had 38 pins and an UFL connector for an external (high gain and directive) antenna. ESP32 Wroon 32D had 38 pins and a PCB antenna. Choose ESP32 Wroon 32U for a better link margin.

SX1280 modules

LAMBDA80C-24D @ Farnell (UFL connector + EM shield)
LAMBDA80C-24S @ Mouser (UFL connector + EM shield)
EByte E28-2G4M20S @ Aliexpress (UFL connector + EM shield)

PCB

Headers and connectors

20-pin stackable headers (x2) for ESP32 : should be resized to 19 pins.
8-pin stackable headers (x2) for Mikrobus modules.
Grove connectors (x3 but optional).

Power (Optional)

Power Profiling

Nordic Power Profiler Kit II

Plug the PPK2 power source (VOUT+GND) on 3V3+GND pin (double-row header and Grove connectors) and DO NOT plug the ESP32 throught the mini-USB connector.