how to get 4 digit decimal no.

Using Arduino Programming Questions
1

i interface with analog voltage at pin no A0 and get the data. than i convert the data in to voltage but it has been showing upto 2 digit no not upto 4 digit no. but i need upto four 4 digit no so how can i get the value up to 4 digit no any suggestion.

2 
Serial.print (myFloatVoltage, 4);

But, with 4mV resolution, this may not be what you want.

(post your code if you want help)

3

do you mean preceding zero's? e.g. 0024 mV?

4

With a print function you can define how many 0's you want after the decimal point
ie print(a0,2); will print to 2 decimal places.
I use this for voltages myself but I have found sometimes if the voltage is under ten and using an LCD 2 line display I will get 3 decimal places instead of 2.
Not sure if this problem occurs on serial monitor.
Hope this helps

5

I use this for voltages myself but I have found sometimes if the voltage is under ten and using an LCD 2 line display I will get 3 decimal places instead of 2.

Can you make a test application that shows this behaviour?

6

Can you make a test application that shows this behaviour?

I'd guess that it only happens when the value drops from over 10 to under 10, and OP isn't clearing the LCD display.