linear hall sensor

Hello I have the linear hall sensor and this is my code,

int readpin = A0;
int incoming = 0;
void setup ()

{Serial.begin(115200);
}
void loop ()
{
incoming = analogRead(readpin) ;
if(incoming > 500){
Serial.print("nothing detected ");
}
if(incoming < 500){
Serial.print(“detecting something.”);
}

and my error message is,

Arduino: 1.8.5 (Windows Store 1.8.10.0) (Windows 10), Board: “Arduino/Genuino Uno”

Archiving built core (caching) in: C:\Users\tbjon\AppData\Local\Temp\arduino_cache_947827\core\core_arduino_avr_uno_a94ab6aaf61dfb93b4a8079c694a14c2.a
Sketch uses 1992 bytes (6%) of program storage space. Maximum is 32256 bytes.
Global variables use 228 bytes (11%) of dynamic memory, leaving 1820 bytes for local variables. Maximum is 2048 bytes.
C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware\tools\avr/bin/avrdude -CC:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware\tools\avr/etc/avrdude.conf -v -patmega328p -carduino -PCOM3 -b115200 -D -Uflash:w:C:\Users\tbjon\AppData\Local\Temp\arduino_build_158021/Hall_sensor_red_.ino.hex:i

avrdude: Version 6.3, compiled on Jan 17 2017 at 12:00:53
Copyright (c) 2000-2005 Brian Dean, http://www.bdmicro.com/
Copyright (c) 2007-2014 Joerg Wunsch

System wide configuration file is “C:\Program Files\WindowsApps\ArduinoLLC.ArduinoIDE_1.8.10.0_x86__mdqgnx93n4wtt\hardware\tools\avr/etc/avrdude.conf”

Using Port : COM3
Using Programmer : arduino
Overriding Baud Rate : 115200
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 1 of 10: not in sync: resp=0x21
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 2 of 10: not in sync: resp=0x21
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 3 of 10: not in sync: resp=0x21
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 4 of 10: not in sync: resp=0x21
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 5 of 10: not in sync: resp=0x21
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 6 of 10: not in sync: resp=0x21
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 7 of 10: not in sync: resp=0x21
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 8 of 10: not in sync: resp=0x21
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 9 of 10: not in sync: resp=0x21
avrdude: stk500_recv(): programmer is not responding
avrdude: stk500_getsync() attempt 10 of 10: not in sync: resp=0x21

avrdude done. Thank you.

Problem uploading to board. See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.

This report would have more information with
“Show verbose output during compilation”
option enabled in File → Preferences.

Serial.println(incoming);
delay(400);
}

any suggestions, thanks

See http://www.arduino.cc/en/Guide/Troubleshooting#upload for suggestions.

So, did you? Lots of good ideas there.