Thus far, I've got nothing on the screen. On cursory examination my "SPI" appears correct, though I'm sure I'm making all sorts of protocol errors with it which I'll fix with time and a bit of trolling the web -- my code is a mishmash of Jim Lynch's and a few others.
Thus far, the backlight appears to be off -- just black screen all the time. I'm driving the backlight boost converter with 5V raw USB, and only getting 4.75 V at the backlight.
So, now the noob questions. If the backlight is has insufficient power (like 4.75V), will I see anything at all on the screen, staring into the inky darkness? I'm looking forward to _not_ having to rig up a separate 5V supply for the backlight (yet), so I'd like to separate out the possibility of a backlight problem (I can't see my brilliant graphics because the backlight doesn't have enough power) from an interface problem (I can't see anything because I haven't initialized the display properly). If the backlight is on but the display uninitialized, is it apparent -- do I get a bright black/blue/white screen?
Simple questions, I know, but would save a lot of experimentation.