adc0804

[gsingh]

i m making a temperature indicator using adc 0804.Microcontroller used is AT89S52 and display will be on 16*2 LCd. The problem is that when I connect the circuit to a 6v supply, all output pins of ADC0804 are either at HIGH state or at LOW state. i mean if the temp is 32 deg C then the output should be 00100000 but in my case the output is 11111111. any suggestions?????

[Kunal]

what is the voltage apllied to Vref of your ADC0804 IC???

[gsingh]

i hav given 5.00V at pin 20 of adc 0804 and 1.28V at pin 9 so as to get a unit change in the digital output for every 10mV change in the input……

[Kunal]

go through this link you may get some idea about connection.

 

http://www.engineersgarage.com/microcontroller/8051projects/interface-ADC0804-AT89C51-circuit

 

or go through this link also u will get multiple ideas

 

http://www.8051projects.net/adc-interfacing/

 

 

[romel emperado]

since you adc is powered with 5vdc then it is impossible to input more than 5v voltage to your adc..

 

if you want to input bigger voltage than in your Vref then you can use voltage devider for that..

 

check this tutorial and working code of adc0804:

http://adf.ly/2GyMI

 

and also check this voltage devider calculator:

 

http://adf.ly/2GyO6

[gsingh]

Is there a possibility that my adc0804 has damaged and thats why it is giving the output 11111111B?????

[Author]

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