add speech recognition english examples.

Author: bitsk

libraries/Maix_Speech_Recognition/examples/voice_control_led_en/voice_control_led_en.ino

@@ -0,0 +1,71 @@
+#include "Maix_Speech_Recognition.h"
+#include "voice_model.h"
+
+SpeechRecognizer rec;
+
+void setup()
+{
+    pinMode(LED_RED, OUTPUT);
+    pinMode(LED_BLUE, OUTPUT);
+    pinMode(LED_GREEN, OUTPUT);
+    rec.begin();
+    Serial.begin(115200);
+    Serial.println("init model...");
+    rec.addVoiceModel(0, 0, red_0, fram_num_red_0); 
+    rec.addVoiceModel(0, 1, red_1, fram_num_red_1); 
+    rec.addVoiceModel(0, 2, red_2, fram_num_red_2); 
+    rec.addVoiceModel(0, 3, red_3, fram_num_red_3); 
+    rec.addVoiceModel(1, 0, green_0, fram_num_green_0);     
+    rec.addVoiceModel(1, 1, green_1, fram_num_green_1);     
+    rec.addVoiceModel(1, 2, green_2, fram_num_green_2);     
+    rec.addVoiceModel(1, 3, green_3, fram_num_green_3);     
+    rec.addVoiceModel(2, 0, blue_0, fram_num_blue_0);   
+    rec.addVoiceModel(2, 1, blue_1, fram_num_blue_1);   
+    rec.addVoiceModel(2, 2, blue_2, fram_num_blue_2);   
+    rec.addVoiceModel(2, 3, blue_3, fram_num_blue_3);   
+    rec.addVoiceModel(3, 0, turnoff_0, fram_num_turnoff_0);  
+    rec.addVoiceModel(3, 1, turnoff_1, fram_num_turnoff_1);  
+    rec.addVoiceModel(3, 2, turnoff_2, fram_num_turnoff_2);  
+    rec.addVoiceModel(3, 3, turnoff_3, fram_num_turnoff_3);  
+    Serial.println("init model ok!");
+}
+void loop()
+{
+    int res;
+    res = rec.recognize();
+    Serial.printf("res : %d ", res);
+    if (res > 0){
+        switch (res)
+        {
+        case 1:
+            digitalWrite(LED_RED, LOW); //power on red led
+            digitalWrite(LED_GREEN, HIGH);
+            digitalWrite(LED_BLUE, HIGH);
+            Serial.println("rec : red ");
+            break;
+        case 2:
+            digitalWrite(LED_GREEN, LOW); //power on green led
+            digitalWrite(LED_RED, HIGH);
+            digitalWrite(LED_BLUE, HIGH);
+            Serial.println("rec : green ");
+            break;
+        case 3:
+            digitalWrite(LED_BLUE, LOW); //power on blue led
+            digitalWrite(LED_RED, HIGH);
+            digitalWrite(LED_GREEN, HIGH);
+            Serial.println("rec : blue ");
+            break;
+        case 4:
+            digitalWrite(LED_RED, HIGH);
+            digitalWrite(LED_GREEN, HIGH);
+            digitalWrite(LED_BLUE, HIGH);   //power off all leds
+            Serial.println("rec : turnoff ");
+        default:
+            break;
+        }
+    }else
+    {
+        Serial.println("recognize failed.");
+    }
+    delay(1000);
+}