Merge pull request #299 from brilliantlabsAR/pairing_flow

Reduced camera image noise  (pink vertical lines) by constraining RGB gain values
Changed the default camera auto exposure settings so that photos are better out of the box
Updated the text displayed during pairing and firmware update to better reflect the status

Author: uma-shankar-TE

source/application/bluetooth.c

@@ -332,6 +332,8 @@ void SD_EVT_IRQHandler(void)
                     bond_storage,
                     (uint32_t *)&bond.keyset.keys_own.p_enc_key->enc_info,
                     sizeof(bond.keyset.keys_own.p_enc_key->enc_info));
+
+                status = show_pairing_screen(true, false);
             }
 
             break;

source/application/lua_libraries/camera.c

@@ -50,11 +50,11 @@ static struct camera_auto_last_values
     double green_gain;
     double blue_gain;
 } last = {
-    .shutter = 500.0f,
+    .shutter = 1600.0f,
     .analog_gain = 1.0f,
-    .red_gain = 1.9f,
-    .green_gain = 1.0f,
-    .blue_gain = 2.2f,
+    .red_gain = 121.6f,
+    .green_gain = 64.0f,
+    .blue_gain = 140.8f,
 };
 
 static struct camera_capture_settings
@@ -561,11 +561,12 @@ static int lua_camera_auto(lua_State *L)
     }
 
     // Default auto exposure settings
-    camera_metering_mode_t metering = AVERAGE;
-    double target_exposure = 0.18;
-    double exposure_speed = 0.50;
-    double shutter_limit = 1600.0;
-    double analog_gain_limit = 60.0;
+    camera_metering_mode_t metering = CENTER_WEIGHTED;
+    double target_exposure = 0.1;
+    double exposure_speed = 0.45;
+    double shutter_limit = 16383.0;
+    double analog_gain_limit = 16.0;
+    double rgb_gain_limit = 287.0;
 
     // Default white balance settings
     double white_balance_speed = 0.5;
@@ -655,6 +656,17 @@ static int lua_camera_auto(lua_State *L)
 
             lua_pop(L, 1);
         }
+
+        if (lua_getfield(L, 1, "rgb_gain_limit") != LUA_TNIL)
+        {
+            rgb_gain_limit = luaL_checknumber(L, -1);
+            if (rgb_gain_limit < 0.0 || rgb_gain_limit > 1023.0)
+            {
+                luaL_error(L, "rgb_gain_limit must be between 0 and 1023");
+            }
+
+            lua_pop(L, 1);
+        }
     }
 
     // Get current brightness from FPGA
@@ -668,6 +680,25 @@ static int lua_camera_auto(lua_State *L)
     double matrix_g = metering_data[4] / 255.0f;
     double matrix_b = metering_data[5] / 255.0f;
 
+    if (spot_r == 0.0) {
+        spot_r = 0.0001;
+    }
+    if (spot_g == 0.0) {
+        spot_g = 0.0001;
+    }
+    if (spot_b == 0.0) {
+        spot_b = 0.0001;
+    }
+    if (matrix_r == 0.0) {
+        matrix_r = 0.0001;
+    }
+    if (matrix_g == 0.0) {
+        matrix_g = 0.0001;
+    }
+    if (matrix_b == 0.0) {
+        matrix_b = 0.0001;
+    }
+
     double spot_average = (spot_r + spot_g + spot_b) / 3.0;
     double matrix_average = (matrix_r + matrix_g + matrix_b) / 3.0;
     double center_weighted_average = (spot_average +
@@ -769,6 +800,10 @@ static int lua_camera_auto(lua_State *L)
                                 ? matrix_g / last.green_gain
                                 : matrix_b / last.blue_gain);
 
+    // scale normalized RGB values to the gain scale
+    max_rgb *= 256.0;
+
+    // target per-channel gains that we blend towards
     double red_gain = max_rgb / matrix_r * last.red_gain;
     double green_gain = max_rgb / matrix_g * last.green_gain;
     double blue_gain = max_rgb / matrix_b * last.blue_gain;
@@ -777,19 +812,6 @@ static int lua_camera_auto(lua_State *L)
     double blending_factor = (scene_brightness - white_balance_min_activation) /
                              (white_balance_max_activation -
                               white_balance_min_activation);
-
-    if (red_gain > 1023.0)
-    {
-        red_gain = 1023.0;
-    }
-    if (green_gain > 1023.0)
-    {
-        green_gain = 1023.0;
-    }
-    if (blue_gain > 1023.0)
-    {
-        blue_gain = 1023.0;
-    }
     if (blending_factor > 1.0)
     {
         blending_factor = 1.0;
@@ -811,9 +833,51 @@ static int lua_camera_auto(lua_State *L)
                          (blue_gain - last.blue_gain) +
                      last.blue_gain;
 
-    uint16_t red_gain_uint16 = (uint16_t)(last.red_gain * 256.0);
-    uint16_t green_gain_uint16 = (uint16_t)(last.green_gain * 256.0);
-    uint16_t blue_gain_uint16 = (uint16_t)(last.blue_gain * 256.0);
+    double max_rgb_gain = last.red_gain > last.green_gain
+                            ? (last.red_gain > last.blue_gain
+                                ? last.red_gain
+                                : last.blue_gain)
+                            : (last.green_gain > last.blue_gain
+                                ? last.green_gain
+                                : last.blue_gain);
+
+    // Scale per-channel gains so the largest channel is at most rgb_gain_limit
+    if (max_rgb_gain > rgb_gain_limit)
+    {
+        double scale_factor = rgb_gain_limit / max_rgb_gain;
+        last.red_gain *= scale_factor;
+        last.green_gain *= scale_factor;
+        last.blue_gain *= scale_factor;
+    }
+
+    if (last.red_gain > 1023.0)
+    {
+        last.red_gain = 1023.0;
+    }
+    if (last.red_gain <= 0.0)
+    {
+        last.red_gain = 0.0001;
+    }
+    if (last.green_gain > 1023.0)
+    {
+        last.green_gain = 1023.0;
+    }
+    if (last.green_gain <= 0.0)
+    {
+        last.green_gain = 0.0001;
+    }
+    if (last.blue_gain > 1023.0)
+    {
+        last.blue_gain = 1023.0;
+    }
+    if (last.blue_gain <= 0.0)
+    {
+        last.blue_gain = 0.0001;
+    }
+
+    uint16_t red_gain_uint16 = (uint16_t)(last.red_gain);
+    uint16_t green_gain_uint16 = (uint16_t)(last.green_gain);
+    uint16_t blue_gain_uint16 = (uint16_t)(last.blue_gain);
 
     check_error(i2c_write(CAMERA, 0x5180, 0x03, red_gain_uint16 >> 8).fail);
     check_error(i2c_write(CAMERA, 0x5181, 0xFF, red_gain_uint16).fail);

source/application/lua_libraries/system.c

@@ -36,6 +36,12 @@
 
 static int lua_update(lua_State *L)
 {
+    int status = show_pairing_screen(false, true);
+    if (status != LUA_OK)
+    {
+        const char *lua_error = lua_tostring(L, -1);
+        luaL_error(L, "%s", lua_error);
+    }
     check_error(sd_power_gpregret_set(0, 0xB1));
     NVIC_SystemReset();
     return 0;

source/application/luaport.c

@@ -63,6 +63,39 @@ void lua_break_signal_interrupt(void)
                 1);
 }
 
+int show_pairing_screen(bool is_paired, bool is_update)
+{
+    int status;
+    if(L_global == NULL)
+    {
+        return LUA_ERRRUN;
+    }
+    if (is_update)
+    {
+        status = luaL_dostring(L_global, "frame.display.text('Frame Update', 200, 140);"
+                                       "frame.display.show();");
+    }
+    else if (!is_paired)
+    {
+         status = luaL_dostring(L_global, "frame.display.text('Ready to Pair', 200, 140);"
+                                      "frame.display.text('Frame '..frame.bluetooth.address():sub(-2, -1), 245, 210, { color = 'GREEN' });"
+                                      "frame.display.show();");
+    }
+    else
+    {
+         status = luaL_dostring(L_global, "frame.display.text('Frame is Paired', 185, 140);"
+                                      "frame.display.text('Frame '..frame.bluetooth.address():sub(-2, -1), 245, 210, { color = 'ORANGE' });"
+                                      "frame.display.show();");
+    }
+
+    if (status != LUA_OK)
+    {
+        lua_pop(L_global, -1);
+        error();
+    }
+    return status;
+}
+
 void run_lua(bool is_paired)
 {
     lua_State *L = luaL_newstate();
@@ -127,24 +160,8 @@ void run_lua(bool is_paired)
     }
 
     // Show splash screen
-    if (!is_paired)
-    {
-        status = luaL_dostring(L, "frame.display.text('Ready to Pair', 200, 140);"
-                                  "frame.display.text('Frame '..frame.bluetooth.address():sub(-2, -1), 245, 210, { color = 'GREEN' });"
-                                  "frame.display.show();");
-    }
-    else
-    {
-        status = luaL_dostring(L, "frame.display.text('Frame is Paired', 185, 140);"
-                                  "frame.display.text('Frame '..frame.bluetooth.address():sub(-2, -1), 245, 210, { color = 'ORANGE' });"
-                                  "frame.display.show();");
-    }
+    status = show_pairing_screen(is_paired, false);
 
-    if (status != LUA_OK)
-    {
-        lua_pop(L, -1);
-        error();
-    }
 
     //  Run REPL
     while (true)

source/application/luaport.h

@@ -29,7 +29,7 @@
 #include <stdio.h>
 #include "bluetooth.h"
 #include "nrfx_log.h"
-
+#include "lua.h"
 #define lua_writestring(s, l) bluetooth_send_data((uint8_t *)s, l)
 #define lua_writeline()
 #define lua_writestringerror(s, p) printf(s, p)
@@ -38,4 +38,6 @@ void lua_write_to_repl(uint8_t *buffer, uint8_t length);
 
 void lua_break_signal_interrupt(void);
 
-void run_lua(bool is_paired);
+void run_lua(bool is_paired);
+
+int show_pairing_screen(bool is_paired, bool is_update);