[steponme82]

@isod89

The button lights work on my BlackBox. This is the driver from #8.

What they show:
1: AMP, MOD, DLY, REV and CAB are lit while their block is on
2: FX is lit while any block of the FX group is on (drive, SFX, synth, pitch, comp, gate, EQ). It's the same list the FX button cycles through, now UI_FXB in ui.h so both use it
3: HOME blinks while the tuner is open
4: all dark during an update

How:
1: px_leds.h drives the 595 the way you read it (DS PC8, SHCP PC5, STCP PC6). At init it loads the all-off byte, then drives PC7 low, like stock. PC7 is the lights' enable, not a screen line. lcd_init and input_init still set it high at boot, only their comments changed
2: px_lights.h builds the byte once per main loop pass and writes it only when it changes. On the wire a 0 lights, so it goes out inverted like stock
3: led_probe.h is the LED map build I used to read the bits (LED_PROBE 1, off by default). It can map a Pocket X too
4: tests/lpsim.c and tests/lightsim.c model the 595 with its enable on PC7. Both run in tests/run_tests.sh

Tested:
1: on my BlackBox the lights follow the blocks, also when I change preset, and HOME blinks in the tuner
2: the host tests all pass, and the two new tests catch all 19 deliberate mistakes I tried in the code
3: the CI build on my fork compiles with no warnings

Not tested on a Pocket X. The same firmware runs there and you found the same routine, but the bit order may be different. If you can, install it and check that each light sits on the right button. If not, LED_PROBE 1 gives the map in a minute.

Not in this PR: a setting to switch the lights off. It needs a place to save settings, and VinSpee's #10 adds the first one. I'll add it on top once #10 is in.

Heads up: #10 and #16 also add lines after the screen step in tests/run_tests.sh, so whichever goes in second gets a small conflict there. Keep both blocks.

🤖 Generated with Claude Code

[isod89]

@steponme82 NICE JOB! please read #16 more info about my current work. thank you so much for you help

[steponme82]

@isod89

Thanks! No rush, v37 first.

1: once v37 is pushed I'll rebase #17 on it myself, so you don't have to deal with the conflicts
2: the lights-off setting comes after that, on top of the settings store from #10
3: since the memory layout is changing, keep in mind the 021 point I left on #16. On a BlackBox that ran 021, the install overwrites the first 16K of its VM

If a second pair of eyes helps with the NAM speed, I have JieLi's objdump running here and I can go through how 021 uses the vector unit and the second core. Tell me where to start.