This board is a Raspberry PI Hat for the RAK833/RAK2247 LoRa Concentrator Gateway Modules. The RAK2247 is improved version of the RAK833 with better heatsinking, a boost in the maximum transmission power and improved interference immunity.
Both are a smaller version of the popular RAK831. The RAK831 is larger, about the same footprint than a Raspberry PI and requires a breakout board to convert the RAK831’s 24 pin connector to the Raspberry PI’s 40 pin connector. The RAK833 is a more elegant industry standard PCI Express Mini Card form factor (Type F2).
The RAK833 module consists of a Semtech SX1301 Digital Baseband chip for outdoor LoRaWAN Macro Gateways and two Semtech SX1257 Transceivers. The USB interface is provided by an FTDI FT2232H.
It supports both a USB and SPI interface selectable via the SPDT_SEL pin. This makes the module ideal for Raspberry PI and other Embedded Linux platforms that do no expose USB on the expansion connector.
Variants of the module are available for four different frequency ranges, 433MHz, 470MHz (China), 868MHz (Europe) & 915MHz (North America) and with or without the USB interface (FT2232H).
The RAK833-SPI/USB-xxx Mini PCie Module can be purchased from AliExpress for US$119. The non-USB version, the RAK833-SPI-xxx is US$99
Pinout
The following table provides details of the allocated I/O.
| Pin No. | PI Name | PI I/O Type | Net Name | Function |
|
8 | GPIO14/TXD0 | OUTPUT | UART_TX | GPS Receive (For configuration) |
|
10 | GPIO15/RXD0 | INPUT | UART_RX | GPS Transmit |
|
19 | GPIO10/SPI_MOSI | OUTPUT | PCIe_MOSI | SX1301 SPI Slave Input |
|
21 | GPIO09/SPI_MISO | INPUT | PCIe_MISO | SX1301 SPI Slave Output |
|
22 | GPIO25 | OUTPUT | PCIe_RESET | SX1301 Reset |
|
23 | GPIO11/SPI_SCK | OUTPUT | PCIe_SCK | SX1301 SPI Clock |
|
24 | GPIO08/SPI_CE0_N | OUTPUT | PCIe_CSN | SX1301 Chip Select |
Design Files
Design files can be downloaded from the Circuit Maker website. Circuit Maker is a free EDA tool from Altium.
- Open in Altium 365
- RAK833 version 1.A.4 Gerbers (Zip)
- RAK833 version 1.A.4 Schematics (PDF)
- RAK833 version 1.A.4 Bill of Materials (XLSX)
The PCB for this design was fabricated by JLCPCB.com. An earlier prototype was fabricated by pcbway.com.
Software – Basic Station
Instructions on how to install LoRA Basic Station can be found here.