New "import SDK example" and modify for MaaXBoard-RT:
tjaekel/MaaXBoard-RT_lpspi_edma_b2b_transfer_master_cm7: MaaXBoard-RT LPSPI4 demo (github.com)
LPSPI4 demo plus GPIO INT demo:
This project demonstrates how to initialize and use the LPSPI4, populate on J1 header pins.
Plus: how to use GPIO Input Interrupt, here using the User Button switch.
Remarks:
- The LPSPI4 pins were NOT initialized in the file "pin_mux.c" : added
This file does not seem to support the initialization of "all" features on the MaaXBoard-RT,
some pin configs are missing (or not supported, e.g. LPSPI4 for SPI on J1 header). - The AVNET User Guide seems to have a flip on SPI_MISO and SPI_MOSI
Anybody with a better pin table?
Does anybody have a better table for the J1 signals?
Especially:
The pin name as "LPSPI4_SCK" is not very informative (neither helpful).
Better would be to have there "IOMUXC_GPIO_DISP_B2_12_LPSPI4_SCK", because it is NOT
the other one, for "SD".
I had to figure out which LPSPI4_SCK pin is used (no schematics available).
Great would be to have the pin names as used in SDK drivers or datasheet.
How to test?
Connect SPI_MISO with SPI_MOSI (pin 19) with SPI_MOSI (pin 21), via a wire:
It should "mirror" what was sent and result in an error free comparison (Rx = Tx).
The GPIO INT is based on the User Button:
Press and hold the User Button before you hit any key in UART (the Debug UART, LPUART1, is used, via MCU-LINK):
It will tell you if the INT and Button Press was seen (but edge triggered).