diff --git a/crickets/src/main.cpp b/crickets/src/main.cpp
index 17fb697..db02a3b 100755
--- a/crickets/src/main.cpp
+++ b/crickets/src/main.cpp
@@ -21,7 +21,7 @@
 //============<identities>============
 //
 #define MY_GROUP_ID   (3000)
-#define MY_ID         (MY_GROUP_ID + 20)
+#define MY_ID         (MY_GROUP_ID + 53)
 #define MY_SIGN       ("CRICKET")
 //
 //============</identities>============
@@ -242,6 +242,9 @@ void setup() {
   //led
   pinMode(LED_PIN, OUTPUT);
 
+  //pwm freq.
+  analogWriteFreq(40000);
+
   //serial
   Serial.begin(115200);
   delay(100);
diff --git a/id.list b/id.list
index 91b8485..e0949d3 100644
--- a/id.list
+++ b/id.list
@@ -28,5 +28,9 @@
 - @sampler
     == @sampler x N ~ 5001, 5002, 5003, ...
 
+- (new)
+    == cricket x 1 ~ 3087
+    == cricket x 1 ~ 3107
+
 - unused
     == gonggong x 1 ~ 4001