Harry Potter and The Reuse Of The Shield

The first prototype of XFM running on a Digilent CMOD A7 is alive. I reused the previous shield by using this “wire jungle” arrangement shown in the picture.

The bad news: the CMOD A7 35T is USD 89, so using it to build XFM won’t be a sub-50 project anymore. Also, it doesn’t have a 32U4, so no freebies for the UI expansion.

The good news: this prototype works smoothly, and is actually running two XFM instances, conveniently sharing the program memory and MIDI connection.
So this build is now a 64-voice, 2-part multitimbral FM synth. The CMOD is also way smaller. It uses an Artix A7 FPGA, in BGA form, and requires changing the toolchain to Vivado. Somehow it made the HDL synthesis worse in terms of resource usage, but at least is future-proof.

The board also has onboard SRAM. I wonder if I could squeeze some fabric to add a delay effect. And individual outputs. And some more features. Still a lot to do and test.