are you positive you are picking the correct pin? BelaMini Multichannel Audio has the silkscreen wrong for D10, in case you were using that as a reference.
Did you run these lines or at least the first and third ones?
config-pin P2.25 spi;
config-pin P2.27 spi;
config-pin P2.29 spi_sclk;
config-pin P2.31 spi_cs;
I suspect the first one was not run (or you are using the wrong pin) because setting pinMode
in Bela shouldn't affect the pin's behaviour at all if the pin has been muxed to SPI.
Btw, once you get some signal on the MOSI line, you may want to try my attempt at DotStar here, which was not properly tested.