Very curious.
Are you sure you are getting the correct code loaded into the Nano?
Perhaps I am wrong to assume the Nano will write to the display,
perhaps one of the other connections is hanging it up.
You may need help from someone familiar with your particular firmware.
Yes 0 to 5v, not 0 to 3.3v.
That activity may be just a quick burst immediately after power up or Nano reset,
only lasting for a few milliseonds.
Perhaps even less, the SPI bus can be very fast.
Jerry, KE7ER
On Wed, Feb 10, 2021 at 06:49 PM, John Terrell wrote:
With or without the screen attached, and whether or not the Raduino is powered by the main board or removed from the main board and powered by the USB connector on the Nano, there is no activity on CS_TFT, D_C, SDI, SCK, or SDO?on the oscilloscope. What frequency should I expect to see activity? It looks flat regardless. Voltages are 5, 5, 0, 0 and 0 respectively. And I see no output from the Si5351 CLK0, CLK 1 or CLK2.
