SPI_Asm bug

Rayman

My code works with SPI_Spin but not SPI_Asm…

I'm interfacing a Prop with EVE2 based display module.
It's regular SPI, but with 32 bit packet size.


I found the bug (I'm going to call this a bug) in the assembly code, in the MSBFirst_ section:

shl     t5,             arg3              ''          Shift "1" N number of bits to the left.

LSB first works, but MSB first does not for bits=32

This messed me up pretty good, had to break out oscilloscope to figure out what is going on...

Rayman

This version may have bug fixed.
Seems to work for me anyway...

avsa242

Hmm, I can't confirm that particular case as I don't have one, but the change breaks an ssd1331 object for me, vs the original SPI_Asm object, or the spin-standard-library rewrite of it (com.spi.spin), though the 1331 doesn't need the 32bit transaction capability. Maybe this would just be more of an EVE2-specific SPI driver...or maybe there's a way to get it to work with other devices and I'm just not experienced enough

Rayman

Yeah, my driver doesn't work for me anymore either...
Maybe only 32-bit transfers work...
I think I'll just make a new one that does only what I need...

Rayman

kuroneko gave me some code to fix this, see attached, seems to work now.

avsa242

Confirmed here too...thanks Ray and kuroneko!