Doing something similar to the test gadget from a couple years ago, I went with a basic Arduino Nano, the SI5351 module, and a TFT Display. To this I added header pins to bring out pins for a Rotary encoder and other controlls. To an expansion header I brought out DC power, analog, I2C , and the SI5351 clock lines. Since some of the TFT Display modules require 3.3 volt logic levels instead of the 5 volt out of the Nano, I added 1K resistors in the control lines to provide current limit for the display if using a 3.3 v module.
Since I also want to be able to use this as a test_set during construction of the RF stages. I built up a small board with a rotary encoder and 3 push button switches that plugs on to the control header pins on the Arduino controller board.
Looking back at the Sweepering Jr., and different versions of the SNA Jr. projects, I decided to go with much of the original SNA Jr. design. I built a simple add on module that can be used as a Sig.Gen., SNA, RF voltmeter.
I hope to have several other modules that such as an antenna nalyzer. SWR power meter. measurement receiver, and possibly a very simple Spectrum Analyzer for up to about 60 MHz. These will be added as the transceiver project progresses.