Works on SPI0 on an RPI, fails on SPI1

[karalabe]

I cannot even fathom how to debug this. I have two SPI port sets on a RaspberryPI. I can use both SPI0 and SPI1 successfully to interface other hardware, so the ports surely work.

When running my LED driver off of SPI0, everything works. Changing the Bus parameter from Spi0 to Spi1 causes the LEDs to light up almost fully when "off", and when driving them they increase a bit in brightness. If it was a timing issue, I'd expect nothing to appear or more randomness. Any ideas where I might look?

[david-sawatzke]

I could imagine there being some clock differences, leading to every bit being "high". Probably the easiest approach is looking at the signal with a logic analyzer or an oscilloscope. The cheapest useful device (which I generally recommend if you want to do more digital logic) is a FX2 logic analyzer. You can buy one on Amazon or Aliexpress (or others), everything with 24 MHz and 8 Channels is good (under 10$). To use them, sigrok + pulseview work good. With this you can record the signals in both cases and compare them.