diff --git a/src/main.rs b/src/main.rs
index 1224819..65a45b7 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -131,10 +131,15 @@ fn main() -> ! {
             critical_section::with(|_| {
                 let serial = custom_hid::serial();
 
-                serial.send_text("---");
-                serial.send_number(mouse_sensor.operation_mode(), 10);
-                serial.send_text(" - ");
-                serial.send_number(0xB8, 10);
+                // serial.send_text("---");
+                // serial.send_number(mouse_sensor.product_id_1(), 10);
+                // serial.send_text(" - ");
+                // serial.send_number(0x30, 10);
+
+                // serial.send_text("---");
+                // serial.send_number(mouse_sensor.product_id_2(), 10);
+                // serial.send_text(" - ");
+                // serial.send_number(0x02, 10);
 
                 // custom_hid::serial().send_number(mouse_sensor.product_id_2(), 10);
             });
diff --git a/src/mouse_sensor.rs b/src/mouse_sensor.rs
index 1192a75..96519db 100644
--- a/src/mouse_sensor.rs
+++ b/src/mouse_sensor.rs
@@ -109,16 +109,27 @@ where
             log,
         };
 
-        if me.led.set_low().is_err() {
-            (me.log)("led low failed");
+        if me.led.set_high().is_err() {
+            (me.log)("led high failed");
         }
 
-        if !me.verify_product_id_1() || !me.verify_product_id_2() {
-            if me.led.set_high().is_err() {
-                (me.log)("led high failed");
+        // verify initialization
+        loop {
+            if me.verify_product_id_1() {
+                break;
             }
         }
 
+        loop {
+            if me.verify_product_id_2() {
+                break;
+            }
+        }
+
+        if me.led.set_low().is_err() {
+            (me.log)("led low failed");
+        }
+
         me
     }
 
@@ -144,21 +155,29 @@ where
     }
 
     pub fn read(&mut self, address: u8) -> u8 {
-        self.access(|me| {
-            if me.spi.send(address & Self::READ).is_err() {
-                (me.log)("send address (read) failed");
-            }
-
-            me.delay.delay_us(50);
-
-            match me.spi.read() {
-                Ok(res) => res,
-                Err(_) => {
-                    (me.log)("read failed");
-                    0
+        loop {
+            let res = self.access(|me| {
+                if me.spi.send(address & Self::READ).is_err() {
+                    (me.log)("send address (read) failed");
                 }
+
+                if me.spi.send(0).is_err() {
+                    (me.log)("send dummy (read) failed");
+                }
+
+                match me.spi.read() {
+                    Ok(r) => r << 1,
+                    Err(_) => {
+                        (me.log)("read failed");
+                        0
+                    }
+                }
+            });
+
+            if res != address {
+                return res;
             }
-        })
+        }
     }
 
     pub fn write(&mut self, address: u8, value: u8) {