rpitx-expansion-board

Expansion board for Raspberry Pi 4 Model B that eliminates the need for a direct wired connection of radio equipment (such as antennas, amplifiers, switches, etc.) to GPIO when working with rpitx or rpitx-ui packages. Now, you can use coaxial SMA output, switchable filters, and built-in LNA on one board!

The expansion board is installed by connecting it to the 40-pin Raspberry Pi header and can be fixed additionally by connecting holes on the Raspberry Pi and the expansion board.

Current development progress:

  

Application usage:

Installing and using rpitx-control application:

sudo apt update && sudo apt install git pipx
git clone https://github.com/IgrikXD/rpitx-expansion-board
cd rpitx-expansion-board
pipx ensurepath
pipx install .
rpitx-control

Before building and installing the control application, you can perform the following steps (not required if you plan to use the application normally):

Enabling debugging mode (while the program is running, the log file APPLICATION_DIR/DebugInfo.log is created):

sed -i 's/SHOW_DEBUG_INFO = False/SHOW_DEBUG_INFO = True/' ControlApplication/main.py

Enabling the use of MockFactory to simulate GPIO ports (used to run and debug the application on non-Raspberry Pi devices):

sed -i 's/IS_MOCK_GPIO_USED = False/IS_MOCK_GPIO_USED = True/' ControlApplication/main.py

Uninstalling the rpitx-control application:

pipx uninstall rpitx-control

Current available implementations at EasyEDA platform:

Expansion boards without built-in LNA:

• rpitx-expansion-board-SP3T - Expansion board with 3 switchable filters (Components list, Assembly guide, Usage guide)
• rpitx-expansion-board-SP4T - Expansion board with 4 switchable filters (Components list, Assembly guide, Usage guide)
• rpitx-expansion-board-SP6T - Expansion board with 6 switchable filters (Components list, Assembly guide, Usage guide)

Expansion boards with built-in LNA:

• rpitx-expansion-board-SP3T-LNA - Expansion board with 3 switchable filters and built-in LNA (Components list, Assembly guide, Usage guide)
• rpitx-expansion-board-SP4T-LNA - Expansion board with 4 switchable filters and built-in LNA (Components list, Assembly guide, Usage guide)
• rpitx-expansion-board-SP6T-LNA - Expansion board with 6 switchable filters and built-in LNA (Components list, Assembly guide, Usage guide)

Basic characteristics of the expansion boards:

RF connector: SMA
Feed line: 50 Ohm coaxial cable
Used PCB Material: FR-4
PCB thickness: 1.6 mm
PCB copper weight: 1 oz

How to use this repository?

The ControlApplication directory contains the source code for the rpitx-control application. The ExpansionBoards directory contains information about all available expansion boards. After selecting a specific board in the Datasheets and Schematics directories, you can find all the necessary technical documentation and schematic files in .pdf format. If you only need GERBER files, you can find them in the appropriate Gerbers directory. In the EasyEDA directory, you can find a list of files for implementing the ready device (files can be imported into EasyEDA editor). Based on submitted files, you can order PCB from factory manufacturing make the device independently.

Additionally, for each expansion board you can find a list of required components, assembly guide and an example of use in conjunction with the rpitx-control application.

Resources:

rpitx project page at GitHub
rpitx-ui project page at GitHub
Buy filters / amplifiers / RF switches

How to contact me?

• E-mail: igor.nikolaevich.96@gmail.com
• Telegram: https://t.me/igrikxd
• LinkedIn: https://www.linkedin.com/in/igor-yatsevich/