Ditched Eagle for EasyEDA and have finally got the hang of it. Created a breakout board similar to one I had for a STM32F4 except for the Teensy 4.1.

Also got my local Teensy delivered and managed to get my library back end hooked up and do some testing.

Tested SD card and SPI Oled SSD1351 with DMA including async.

As the Teensy has no DAC I made an area on the board to attach a DAC daughter board so that any compatible DAC could be used.

Also set up some pins for a 8 bit parallel port which works great.

Front
Click image for larger version. 

Name:	b1.png 
Views:	23 
Size:	162.4 KB 
ID:	27015

Back (with provision to add buck convertor)
Click image for larger version. 

Name:	b2.png 
Views:	18 
Size:	179.2 KB 
ID:	27016

DAC board that can be mounted on main board
Click image for larger version. 

Name:	b3.png 
Views:	20 
Size:	76.3 KB 
ID:	27017

Didn't realize until it came just how small it is!!!