Tool/software: TI-RTOS
Wrote simple SPI test (didn't see any SPI examples readily available -- I am sure they are out there if I looked harder). Connected launchpad SCLK, MOSI, MISO & CS (managing CS in sw on DIO26) directly to scope to verify working as expected: bit order, expected clock, etc. [ 1: clock, 2:MOSI, 3: MISO, 4: CS ]
My motivation was to verify what I expected to happen was actually working, then I could begin testing with our own device.
At first glace all seemed fine, and values decoded correctly, but voltage on MOSI seemed a bit high. Since GPIO pins max at 4.1v, expected < 5v for mosi. MISO seems to be affected by what is sent over MOSI.
The question/concern: it appears that the voltage generated by launchpad (on MOSI pin) is over 30v. That voltage would probably not be very healthy for the components on our board. Something has to be wrong, since only powered by USB. What should I expect for the correct voltage?
Thank you.
scope capture:
