From f9d68cea85a358b59a8bfdbac05ebc15ad5abc8a Mon Sep 17 00:00:00 2001
From: Mr D <darren@darrenlines.uk>
Date: Mon, 18 Oct 2021 18:02:21 +0100
Subject: [PATCH] Added selectable precision to the OSD RPM

I've added selectable precision to the ESC RPM, as shown in the OSD. The default is 3, which is the same as the current RPM display.
---
 docs/Settings.md          | 10 ++++++++++
 src/main/fc/settings.yaml |  8 +++++++-
 src/main/io/osd.c         | 33 +++++++++++++++++++++++++++------
 src/main/io/osd.h         |  1 +
 4 files changed, 45 insertions(+), 7 deletions(-)

diff --git a/docs/Settings.md b/docs/Settings.md
index d53df0dd7e..f030464717 100644
--- a/docs/Settings.md
+++ b/docs/Settings.md
@@ -4122,6 +4122,16 @@ Value above which to make the OSD distance from home indicator blink (meters)
 
 ---
 
+### osd_esc_rpm_precision
+
+Number of characters used to display the RPM value.
+
+| Default | Min | Max |
+| --- | --- | --- |
+| 3 | 3 | 6 |
+
+---
+
 ### osd_esc_temp_alarm_max
 
 Temperature above which the IMU temperature OSD element will start blinking (decidegrees centigrade)
diff --git a/src/main/fc/settings.yaml b/src/main/fc/settings.yaml
index 70789c9ead..3becec8c4e 100644
--- a/src/main/fc/settings.yaml
+++ b/src/main/fc/settings.yaml
@@ -3340,7 +3340,6 @@ groups:
         description: "How many navigation waypoints are displayed, set to 0 (zero) to disable. As sample, if set to 2, and you just passed the 3rd waypoint of the mission, you'll see markers for the 4th waypoint (marked 1) and the 5th waypoint (marked 2)"
         default_value: 0
         field: hud_wp_disp
-
         min: 0
         max: 3
       - name: osd_left_sidebar_scroll
@@ -3476,6 +3475,13 @@ groups:
         min: -36
         max: 36
 
+      - name: osd_esc_rpm_precision
+        description: Number of characters used to display the RPM value.
+        field: esc_rpm_precision
+        min: 3
+        max: 6
+        default_value: 3
+
   - name: PG_OSD_COMMON_CONFIG
     type: osdCommonConfig_t
     headers: ["io/osd_common.h"]
diff --git a/src/main/io/osd.c b/src/main/io/osd.c
index 268815268f..b6f7c2b37f 100644
--- a/src/main/io/osd.c
+++ b/src/main/io/osd.c
@@ -1037,17 +1037,37 @@ static void osdFormatRpm(char *buff, uint32_t rpm)
 {
     buff[0] = SYM_RPM;
     if (rpm) {
-        if (rpm >= 1000) {
-            osdFormatCentiNumber(buff + 1, rpm / 10, 0, 1, 1, 2);
-            buff[3] = 'K';
-            buff[4] = '\0';
+        if ( digitCount(rpm) > osdConfig()->esc_rpm_precision) {
+            uint8_t rpmMaxDecimals = (osdConfig()->esc_rpm_precision - 3);
+            osdFormatCentiNumber(buff + 1, rpm / 10, 0, rpmMaxDecimals, rpmMaxDecimals, osdConfig()->esc_rpm_precision-1);
+            buff[osdConfig()->esc_rpm_precision] = 'K';
+            buff[osdConfig()->esc_rpm_precision+1] = '\0';
         }
         else {
-            tfp_sprintf(buff + 1, "%3lu", rpm);
+            switch(osdConfig()->esc_rpm_precision) {
+                case 6:
+                    tfp_sprintf(buff + 1, "%6lu", rpm);
+                    break;
+                case 5:
+                    tfp_sprintf(buff + 1, "%5lu", rpm);
+                    break;
+                case 4:
+                    tfp_sprintf(buff + 1, "%4lu", rpm);
+                    break;
+                case 3:
+                default:
+                    tfp_sprintf(buff + 1, "%3lu", rpm);
+                    break;
+            }
+
+            
         }
     }
     else {
-        strcpy(buff + 1, "---");
+        uint8_t buffPos = 1;
+        while (buffPos <=( osdConfig()->esc_rpm_precision)) {
+            strcpy(buff + buffPos++, "-");
+        }
     }
 }
 #endif
@@ -3148,6 +3168,7 @@ PG_RESET_TEMPLATE(osdConfig_t, osdConfig,
     .osd_home_position_arm_screen = SETTING_OSD_HOME_POSITION_ARM_SCREEN_DEFAULT,
     .pan_servo_index = SETTING_OSD_PAN_SERVO_INDEX_DEFAULT,
     .pan_servo_pwm2centideg = SETTING_OSD_PAN_SERVO_PWM2CENTIDEG_DEFAULT,
+    .esc_rpm_precision = SETTING_OSD_ESC_RPM_PRECISION_DEFAULT,
 
     .units = SETTING_OSD_UNITS_DEFAULT,
     .main_voltage_decimals = SETTING_OSD_MAIN_VOLTAGE_DECIMALS_DEFAULT,
diff --git a/src/main/io/osd.h b/src/main/io/osd.h
index e46a3bc0bb..fffdc37bf3 100644
--- a/src/main/io/osd.h
+++ b/src/main/io/osd.h
@@ -383,6 +383,7 @@ typedef struct osdConfig_s {
     uint8_t crsf_lq_format;
     uint8_t sidebar_height;             // sidebar height in rows, 0 turns off sidebars leaving only level indicator arrows
     uint8_t telemetry; 				    // use telemetry on displayed pixel line 0
+    uint8_t esc_rpm_precision;          // Number of characters used for the RPM numbers.
 
 } osdConfig_t;