Teensy4.X with PJRC audio card Arduino based SDR Radio project.
The project has a forum and more wiki pages and info at https://groups.io/g/keithsdr
This is a GitHub Repository for Group Member builds and variations of hardware and feature experiments. There is a simpler version maintained by Keith, and this is my derivative, maintained by me, Mike.
The folder SDR_RA8875 is one such SDR project folder and is built on Teensy 4.1 with Audio Card and RA8875 based capacitive touchscreen at 800x480, or a RA8876 capacitive touchscreen at 1024x600. The UI elements use table driven data so they are resizeable/relocatable. The size screen is less important than the controller used. I am leveraging the BTE (Bit Transfer Engine) feature of these controllers to offload the CPU enabling high resolution spectrum and waterfall graphics with minimal CPU overhead.
More pics at https://github.com/K7MDL2/KEITHSDR/tree/main/SDR_RA8875/Pictures
and at my website https://k7mdl2.wixsite.com/k7mdl/copy-of-teensy-4-sdr
Features:
See the README file in each project for specifics about that build.
UI as of 3/25/2021. 40M FT-8. Testing colors and styles of indicators.
Sample rate at 102.4KHz with 4096 point I and Q FFT on a 800x480 4.3" display. 24% max CPU, 4% average. 1:1 bins-per-pixel mapping.
There are many Wiki Pages with hardware and software notes and how to build and configure. I sugest reviewing them and then this page to start your first build. https://github.com/K7MDL2/KEITHSDR/wiki/Getting-Started-Building-SDR_887x-SDR-program