From 08b0940d732b94e6080e57d534d3d0de92dc5436 Mon Sep 17 00:00:00 2001
From: Me Here <me@here>
Date: Mon, 1 Jun 2026 07:54:23 -0500
Subject: [PATCH] pm-kit: redraw periodically (~7fps) so the metronome reliably
 appears

Blank-screen fix attempt: the single boot-time draw (right after the init DISPON)
was likely lost; the peripheral test worked because it redrew every frame. Redraw
on change AND every ~140ms. (Audio timing checked between redraws; partial/playhead
redraw is the next step to tighten it.)

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
---
 rust/pm-kit/src/main.rs | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/rust/pm-kit/src/main.rs b/rust/pm-kit/src/main.rs
index 0e0e95c..9091b73 100644
--- a/rust/pm-kit/src/main.rs
+++ b/rust/pm-kit/src/main.rs
@@ -184,6 +184,7 @@ fn main() -> ! {
     let (mut pa, mut pb) = (false, false);
     let mut joy_zone = 0i8;
     let mut full_redraw = true;
+    let mut last_draw_us = 0u64;
     let mut hb = false;
     let mut hb_us = 0u64;
     led.set_low().unwrap();
@@ -262,8 +263,9 @@ fn main() -> ! {
             let _ = spk.channel_b.set_duty_cycle(0);
         }
 
-        // ---- draw: full screen only on change; the bar-position strip every frame ----
-        if full_redraw {
+        // ---- draw: on change, and periodically (so a draw lost right after init reappears, and
+        // the playhead advances). ~7 fps; partial/playhead-only redraw is the next optimization. ----
+        if full_redraw || now.wrapping_sub(last_draw_us) > 140_000 {
             let lanes: Vec<pm_ui::LaneView> = track
                 .lanes
                 .iter()
@@ -282,8 +284,8 @@ fn main() -> ! {
                 pm_ui::draw_metronome(&mut display, &screen).ok();
             }
             full_redraw = false;
+            last_draw_us = now;
         }
-        let _ = pm_ui::draw_progress(&mut display, phase, playing, 62);
 
         // heartbeat LED (~1 Hz)
         if now.wrapping_sub(hb_us) > 500_000 {