# Temperature Sensor with buzzer **URL:** \ **Category:** Programming\ **Created:** [October 26, 2020, 3:01am UTC](https://forum.arduino.cc/t/temperature-sensor-with-buzzer/680007 "2020-10-26T03:01:54Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![unknowniiix](https://avatars.discourse-cdn.com/v4/letter/u/dec6dc/32.png) [@unknowniiix](https://forum.arduino.cc/u/unknowniiix)\ **Post date:** [October 26, 2020, 3:01am UTC](https://forum.arduino.cc/t/temperature-sensor-with-buzzer/680007/1 "2020-10-26T03:01:54Z")
This is the code i use float temp; float tempC = 0; float tempF = 0; int buzzer = 7; void setup() { pinMode(A0, INPUT); pinMode(buzzer, OUTPUT); Serial.begin(9600); } void loop() { temp = analogRead(A0); temp =((temp\*5)/1024); tempC = (temp-0.5)_100; tempF = ((tempC_9)/5 + 32); Serial.print("Temperature = "); Serial.print(tempC); Serial.print(" C , "); Serial.print(tempF); Serial.println(" F "); if (temp \<=22) { noTone(buzzer); delay(1000); } if (temp \>= 18 && temp \<= 22) { noTone(buzzer); delay(1000); } if (temp \> 23) { tone(7, 1000); delay(200); } } I can simulate it with no errors but i have a problem if the temperature is greather than 23 there no sound coming from buzzer how to solve it? ![tmp.png](https://europe1.discourse-cdn.com/arduino/original/4X/d/5/c/d5c33a7d8bad5105d14095aa78aa305a6ca25084.png) ![tmp circuit.png](https://europe1.discourse-cdn.com/arduino/original/4X/3/1/5/31511793732aaa99924704d63070c937ff39aa4d.png) ![tmp.png](https://europe1.discourse-cdn.com/arduino/original/4X/d/5/c/d5c33a7d8bad5105d14095aa78aa305a6ca25084.png) ![tmp circuit.png](https://europe1.discourse-cdn.com/arduino/original/4X/3/1/5/31511793732aaa99924704d63070c937ff39aa4d.png) ---
**Author:** ![wildbill](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/wildbill/32/1126438_2.png) [@wildbill](https://forum.arduino.cc/u/wildbill)\ **Post date:** [October 26, 2020, 3:11am UTC](https://forum.arduino.cc/t/temperature-sensor-with-buzzer/680007/2 "2020-10-26T03:11:57Z")
You're displaying tempC and tempF, but your buzzer code relies on temp. An issue there I suspect. ---
**Author:** ![IoT\_hobbyist](https://avatars.discourse-cdn.com/v4/letter/i/e5b9ba/32.png) [@IoT\_hobbyist](https://forum.arduino.cc/u/IoT_hobbyist)\ **Post date:** [October 26, 2020, 7:02am UTC](https://forum.arduino.cc/t/temperature-sensor-with-buzzer/680007/3 "2020-10-26T07:02:18Z")
I think you need to change temp inside if to tempC ---
**Author:** ![TomGeorge](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/tomgeorge/32/215261_2.png) [@TomGeorge](https://forum.arduino.cc/u/TomGeorge)\ **Post date:** [October 26, 2020, 9:57am UTC](https://forum.arduino.cc/t/temperature-sensor-with-buzzer/680007/4 "2020-10-26T09:57:37Z")
Hi, Welcome to the forum. Please read the post at the start of any forum , entitled "How to use this Forum". OR [http://forum.arduino.cc/index.php/topic,148850.0.html](http://forum.arduino.cc/index.php/topic,148850.0.html). Then look down to item #7 about how to post your code. It will be formatted in a scrolling window that makes it easier to read. Thanks.. Tom... 🙂 ---
**Author:** ![Idahowalker](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/idahowalker/32/238858_2.png) [@Idahowalker](https://forum.arduino.cc/u/Idahowalker)\ **Post date:** [October 26, 2020, 10:40am UTC](https://forum.arduino.cc/t/temperature-sensor-with-buzzer/680007/5 "2020-10-26T10:40:12Z")
As was written you are comparing apples (floats) to oranges (integers) is what you do ```cpp [color=#222222] if (temp > 23)[/color][color=#222222][/color] [color=#222222]  {[/color][color=#222222][/color] [color=#222222]    tone(7, 1000);[/color][color=#222222][/color] [color=#222222]    delay(200);[/color][color=#222222][/color] [color=#222222]  } ``` Is what I'd do ```cpp if (tempC > 23.0f)   {tone(7, 1000);   delay(200);} ``` See the difference? You are using the raw AD value (temp), I am using the calculated C value. Also when using floats and you use a literal to compare a float value against, I found it is best to fully describe your literal. 23 describes a literal integer, 23.0f describes a float literal. A 23 integer is not really equal to a 23.0f float as some resolution is lost in the implicit conversion. ---
**Author:** ![Idahowalker](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/idahowalker/32/238858_2.png) [@Idahowalker](https://forum.arduino.cc/u/Idahowalker)\ **Post date:** [October 26, 2020, 10:53am UTC](https://forum.arduino.cc/t/temperature-sensor-with-buzzer/680007/6 "2020-10-26T10:53:21Z")
This can produce an incorrect result: ```cpp tempC = (temp-0.5)*100; ``` This will reduce the chance of an incorrect result. ```cpp tempC = (temp-0.5f)*100.0f; ``` ---
**Author:** ![unknowniiix](https://avatars.discourse-cdn.com/v4/letter/u/dec6dc/32.png) [@unknowniiix](https://forum.arduino.cc/u/unknowniiix)\ **Post date:** [October 27, 2020, 12:26am UTC](https://forum.arduino.cc/t/temperature-sensor-with-buzzer/680007/7 "2020-10-27T00:26:37Z")
> wildbill: > You're displaying tempC and tempF, but your buzzer code relies on temp. An issue there I suspect. thank you sir for clarifying this And thank you for your all replies i manage to fix it , it finally make sound . I really appreciate all your replies Thank you very much ---
**Author:** ![system](https://dub1.discourse-cdn.com/arduino/user_avatar/forum.arduino.cc/system/32/1140315_2.png) [@system](https://forum.arduino.cc/u/system)\ **Post date:** [May 6, 2021, 12:49am UTC](https://forum.arduino.cc/t/temperature-sensor-with-buzzer/680007/8 "2021-05-06T00:49:10Z")