add Catch Unit example

Author: Gitshaoxiang

examples/Unit/CATCH/CATCH.ino

@@ -0,0 +1,32 @@
+/*
+    Description: Control Catch Unit through PWM.
+*/
+
+#include <M5Stack.h>
+
+const int servoPin = 26;
+int freq = 50;
+int ledChannel = 0;
+int resolution = 10;
+void setup() {
+  // put your setup code here, to run once:
+  M5.begin();
+  M5.Power.begin();
+  M5.Lcd.setCursor(100, 50, 4);
+  M5.Lcd.println("Catch Unit");
+  M5.Lcd.setCursor(40, 120, 4);
+  M5.Lcd.println("Connect to the Port B");
+  ledcSetup(ledChannel, freq, resolution);
+  ledcAttachPin(servoPin, ledChannel);
+}
+
+void loop() {
+  // High level 0.5ms is angle 0°
+  // duty = 0.5/20ms = 0.025, 0.025*1023≈25
+    ledcWrite(ledChannel, 25);
+    delay(2000);
+  // High level 1ms is angle 45°
+  // duty = 1/20ms = 0.05, 0.05*1023≈50
+    ledcWrite(ledChannel, 50);
+    delay(2000);
+}