From f6b6db4167e0b133420138fb9ef94fdfa2e32a08 Mon Sep 17 00:00:00 2001
From: Björn Stenberg <bjorn@haxx.se>
Date: Wed, 19 Nov 2003 14:14:41 +0000
Subject: Don't show battery meter until a proper power reading has been done

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@4042 a1c6a512-1295-4272-9138-f99709370657
---
 apps/status.c        |  4 +++-
 apps/wps-display.c   | 10 +++++++---
 firmware/powermgmt.c | 19 +++++++++++++------
 3 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/apps/status.c b/apps/status.c
index c6f4e4944c..7e9233a63f 100644
--- a/apps/status.c
+++ b/apps/status.c
@@ -175,8 +175,9 @@ void status_draw(bool force_redraw)
         }
 
 #ifdef HAVE_LCD_BITMAP
-        if (battery_state)
+        if (battery_state && (info.battlevel > -1))
             statusbar_icon_battery(info.battlevel, plug_state);
+            
         statusbar_icon_volume(info.volume);
         statusbar_icon_play_state(current_mode + Icon_Play);
         switch (info.repeat) {
@@ -202,6 +203,7 @@ void status_draw(bool force_redraw)
 
 
 #if defined(HAVE_LCD_CHARCELLS)
+    if (info.battlevel > -1)
     lcd_icon(ICON_BATTERY, battery_state);
     lcd_icon(ICON_BATTERY_1, info.battlevel > 25);
     lcd_icon(ICON_BATTERY_2, info.battlevel > 50);
diff --git a/apps/wps-display.c b/apps/wps-display.c
index c6621b1e62..563bb265be 100644
--- a/apps/wps-display.c
+++ b/apps/wps-display.c
@@ -478,10 +478,14 @@ static char* get_tag(struct mp3entry* id3,
                     return buf;
 
                 case 't': /* estimated battery time */
-                    snprintf(buf, buf_size, "%dh %dm",
-                             battery_time() / 60,
-                             battery_time() % 60);
+                {
+                    int t = battery_time();
+                    if (t >= 0)
+                        snprintf(buf, buf_size, "%dh %dm", t / 60, t % 60);
+                    else
+                        strncpy(buf, "?h ?m", buf_size);
                     return buf;
+                }
             }
             break;
 
diff --git a/firmware/powermgmt.c b/firmware/powermgmt.c
index cca44e01bd..80b6a80b2b 100644
--- a/firmware/powermgmt.c
+++ b/firmware/powermgmt.c
@@ -184,15 +184,13 @@ void battery_level_update(void)
     int c = 0;
     int i;
     
-    /* calculate average over last 3 minutes (skip empty samples) */
+    /* calculate maximum over last 3 minutes (skip empty samples) */
     for (i = 0; i < 3; i++)
-        if (power_history[POWER_HISTORY_LEN-1-i]) {
-            level += power_history[POWER_HISTORY_LEN-1-i];
-            c++;
-        }
+        if (power_history[POWER_HISTORY_LEN-1-i] > c)
+            c = power_history[POWER_HISTORY_LEN-1-i];
         
     if (c)
-        level = level / c;  /* avg */
+        level = c;
     else /* history was empty, get a fresh sample */
         level = (adc_read(ADC_UNREG_POWER) * BATTERY_SCALE_FACTOR) / 10000;
 
@@ -448,6 +446,12 @@ static void power_thread(void)
     
     while (1)
     {
+        /* never read power while disk is spinning, unless in USB mode */
+        if (ata_disk_is_active() && !usb_inserted()) {
+            sleep(HZ * 2);
+            continue;
+        }
+        
         /* Make POWER_AVG measurements and calculate an average of that to
          * reduce the effect of backlights/disk spinning/other variation.
          */
@@ -777,6 +781,8 @@ void powermgmt_init(void)
     
     /* init history to 0 */
     memset(power_history, 0x00, sizeof(power_history));
+
+#if 0
     /* initialize the history with a single sample to prevent level
        flickering during the first minute of execution */
     power_history[POWER_HISTORY_LEN-1] =
@@ -797,6 +803,7 @@ void powermgmt_init(void)
     /* if the battery is nearly empty, start charging immediately */
     if (power_history[POWER_HISTORY_LEN-1] < BATTERY_LEVEL_DANGEROUS)
         charger_enable(true);
+#endif
 #endif
 
     create_thread(power_thread, power_stack, sizeof(power_stack),
-- 
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