small tweaks

flash.sh

 then
     echo Resetting Raspberry Pi Pico
     echo -n -e "\\x18" > $SERIAL
+    echo -n -e "\\x18" > $SERIAL
 fi
 
 echo -n Waiting for disk to appear

src/adc.c

 #define BAT_R1 10000.0f
 #define BAT_R2 18000.0f
 
+#define FILTER_OLD 0.75f
+#define FILTER_NEW (1.0f - FILTER_OLD)
+
+static float filtered = 0.0f;
+
+static float bat_read(void) {
+    float v_adc = adc_read() * ADC_CONVERT;
+
+    // Vadc = Vbat * R2 / (R1 + R2)
+    float v_bat = v_adc / (BAT_R2 / (BAT_R1 + BAT_R2));
+    return v_bat;
+}
+
 void bat_init(void) {
     adc_init();
     adc_gpio_init( ADC_PIN);
     adc_select_input( ADC_NUM);
+    filtered = bat_read();
 }
 
 float bat_get(void) {
-    float v_adc = adc_read() * ADC_CONVERT;
-
-    // Vadc = Vbat * R2 / (R1 + R2)
-    float v_bat = v_adc / (BAT_R2 / (BAT_R1 + BAT_R2));
-    return v_bat;
+    filtered = (filtered * FILTER_OLD) + (bat_read() * FILTER_NEW);
+    return filtered;
 }

src/lcd.c

 
 void lcd_draw_bye(void) {
     ssd1306_clear(&disp);
-    ssd1306_draw_string(&disp, 0, 0, 3, "Boot");
-    ssd1306_draw_string(&disp, 0, LCD_HEIGHT / 2, 3, "loader");
+    ssd1306_draw_string(&disp, 6, 5, 3, " Boot-");
+    ssd1306_draw_string(&disp, 8, LCD_HEIGHT / 2 + 5, 3, "loader");
     ssd1306_show(&disp);
 }

src/main.c

 #include "main.h"
 
 #define WATCHDOG_PERIOD_MS 100
-#define LOGO_INIT_MS 1500
+#define LOGO_INIT_MS 1000
 
 static const uint gpio_hw_detect = 21;
 
         sleep_ms(1);
     }
 
-    if (debug_buttons[BTN_REC]) {
+    if (debug_buttons[BTN_REC] && debug_buttons[BTN_CLICK]) {
         lcd_debug_buttons();
-    } else if (!debug_buttons[BTN_H]) {
+    } else if (debug_buttons[BTN_REC] && (!debug_buttons[BTN_CLICK])) {
+        // skip splash screen
+    } else {
         // show splash for a bit and animate LEDs
         for (uint i = 0; i < LED_COUNT; i++) {
             handle_serial_input();

src/ui.c

 
 #include <stdio.h>
 #include <inttypes.h>
+#include <math.h>
 #include "pico/stdlib.h"
 
 #include "adc.h"
 #include "sequence.h"
 #include "ui.h"
 
-#define REDRAW_MS 2000
+#define BAT_FETCH_MS 66
 
 static bool rec_held_down = false;
 static enum ui_modes ui_mode = 0;
 static enum machine_modes machine_mode = 0;
-static uint32_t last_redraw = 0;
+static uint32_t last_bat_fetch = 0;
+static float last_voltage = 0.0f;
 
 enum machine_modes ui_get_machinemode(void) {
     return machine_mode;
         }
     }
 
-    snprintf(bat, sizeof(bat) - 1, "Bat: %.2fV", bat_get());
+    snprintf(bat, sizeof(bat) - 1, "Bat: %.2fV", last_voltage);
     lcd_draw(mode, val, bat);
 }
 
             break;
         }
 
-        case BTN_REC:
+        case BTN_REC: {
+            // reset sequence
+            sequence_init();
+            ui_redraw();
+            break;
+        }
+
         case BTN_D:
         case BTN_H: {
             rec_held_down = val;
             sequence_looptime(!val);
+            if (!val) {
+                ui_redraw();
+            }
             break;
         }
 
 
 void ui_run(void) {
     uint32_t now = to_ms_since_boot(get_absolute_time());
-    if (now >= (last_redraw + REDRAW_MS)) {
-        ui_redraw();
-        last_redraw = now;
+    if (now >= (last_bat_fetch + BAT_FETCH_MS)) {
+        last_bat_fetch = now;
+
+        float volt = bat_get();
+        if (fabsf(volt - last_voltage) >= 0.01f) {
+            last_voltage = volt;
+            ui_redraw();
+        }
     }
 }