I am so happy to make this log entry.  It's been a long haul - probably much more time than I should have spent - but my final vision for tCam is coming together. 

The hardware is based on a new version of gCore, my ESP32 dev board, which replaces the FireCam prototype I have been developing firmware on.  Aside from form-factor the main feature the new gCore brings is a much higher performance display which allows the full 8.7 fps frame rate.  It accomplishes this by using the ESP32's SPI interface running at its fastest rate of 80 MHz feeding a serial-to-parallel converter driving the ILI9488-based display through an 8-bit parallel interface.

Adjusting task priority and SPI bus speeds, along with a larger checksum, has made the communication between tCam-Mini and the tCam firmware reliable.  The shutter control has become a physical button (not shown in the pictures here) which will be mounted in a yet-to-be-designed 3D printed enclosure along with the other electronics.